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1.
  • Sperlich, Billy, et al. (författare)
  • Does a 3-minute all-out test provide suitable measures of exercise intensity at the maximal lactate steady state or peak oxygen uptake for well-trained runners?
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 9:5, s. 807-812
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE:To examine whether a 3-min all-out test can be used to obtain accurate values for the maximal lactate steady state (vMLSS) and/or peak oxygen uptake (VO2peak) of well-trained runners.METHODS:The 15 male volunteers (25 ± 5 y, 181 ± 6 cm, 76 ± 7 kg, VO2peak 69.3 ± 9.5 mL · kg-1 · min-1) performed a ramp test, a 3-min all-out test, and several submaximal 30-min runs at constant paces of vEND (mean velocity during the last 30 s of the 3-min all-out test) itself and vEND +0.2, +0.1, -0.1, -0.2, -0.3, or -0.4 m/s.RESULTS:vMLSS and vEND were correlated (r = .69, P = .004), although vMLSS was lower (mean difference: 0.26 ± 0.32 m/s, 95% CI -.44 to -.08 m/s, P = .007, effect size = 0.65). The VO2peak values derived from the ramp and 3-min all-out tests were not correlated (r = .41, P = .12), with a mean difference of 523 ± 1002 mL (95% CI 31 to 1077 mL).CONCLUSION:A 3-min all-out test does not provide a suitable measure of vMLSS or VO2peak for well-trained runners.
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3.
  • Born, Dennis, et al. (författare)
  • Bringing light into the dark: effects of compression clothing on performance and recovery
  • 2013
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 8:1, s. 4-18
  • Forskningsöversikt (refereegranskat)abstract
    • To assess original research addressing the effect of the application of compression clothing on sport performance and recovery after exercise, a computer-based literature research was performed in July 2011 using the electronic databases PubMed, MEDLINE, SPORTDiscus, and Web of Science. Studies examining the effect of compression clothing on endurance, strength and power, motor control, and physiological, psychological, and biomechanical parameters during or after exercise were included, and means and measures of variability of the outcome measures were recorded to estimate the effect size (Hedges g) and associated 95% confidence intervals for comparisons of experimental (compression) and control trials (noncompression). The characteristics of the compression clothing, participants, and study design were also extracted. The original research from peer-reviewed journals was examined using the Physiotherapy Evidence Database (PEDro) Scale. Results indicated small effect sizes for the application of compression clothing during exercise for shortduration sprints (10-60 m), vertical-jump height, extending time to exhaustion (such as running at VO2maxor during incremental tests), and time-trial performance (3-60 min). When compression clothing was applied for recovery purposes after exercise, small to moderate effect sizes were observed in recovery of maximal strength and power, especially vertical-jump exercise; reductions in muscle swelling and perceived muscle pain; blood lactate removal; and increases in body temperature. These results suggest that the application of compression clothing may assist athletic performance and recovery in given situations with consideration of the effects magnitude and practical relevance.
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4.
  • Born, Dennis, et al. (författare)
  • Muscle oxygenation asymmetry in ice speed skaters is not compensated by compression
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 58-67
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE:The present investigation assessed tissue oxygenation and local blood volume in both vastus lateralis muscles during 3000 m race simulations in elite speed skaters on ice and the effects of leg compression on physiological, perceptual and performance measures.METHODS:Ten (6 female) elite ice speed skaters completed two on-ice trials with and without leg compression. Tissue oxygenation and local blood volume in both vastus lateralis muscles was assessed by applying near-infrared spectroscopy (NIRS). Continuous measures of oxygen uptake, ventilation, heart rate and velocity were conducted throughout the race simulations as well as blood lactate concentration and ratings of perceived exertion before and after the trials. In addition, lap times were assessed.RESULTS:The investigation of tissue oxygenation in both vastus lateralis muscles revealed an asymmetry (P<0.00; effect size=1.81) throughout the 3000 m race simulation. The application of leg compression did not affect oxygenation asymmetry (smallest P=0.99; largest effect size=0.31) or local blood volume (P=0.33; 0.95). Lap times (P=0.88; 0.43), velocity (P=0.24; 0.84), oxygen uptake (P=0.79; 0.10), ventilation (P=0.11; 0.59), heart rate (P=0.21; 0.89), blood lactate concentration (P=0.82; 0.59) and ratings of perceived exertion (P=0.19; 1.01) were also unaffected by the different types of clothing.CONCLUSION:Elite ice speed skaters show an asymmetry in tissue oxygenation of both vastus lateralis muscles during 3000 m events remaining during the long gliding phases along the straight sections of the track. Based on our data, we conclude no performance enhancing benefits from wearing leg compression under a normal racing suit.
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5.
  • Born, Dennis, et al. (författare)
  • Near-Infrared Spectroscopy: More Accurate Than Heart Rate for Monitoring Intensity in Running in Hilly Terrain
  • 2017
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 12:4, s. 440-447
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose:To 1) investigate the cardiorespiratory and metabolic response of trail running and 2) evaluate whether heart rate (HR) adequately reflects the exercise intensity or whether the tissue saturation index (TSI) could provide a more accurate measure when running in hilly terrain.Methods:Seventeen competitive runners (female: n=4, V’O2max: 55±6 mL·kg−1·min−1; male: n=13, V’O2max: 68±6 mL·kg−1·min−1) performed a time trial on an off-road trail course. The course was made up of two laps covering a total distance of 7 km and included six steep up- and downhill sections with an elevation gain of 486 m. All runners were equipped with a portable breath-by-breath gas analyzer, HR belt, global positioning system receiver and near-infrared spectroscopy (NIRS) device to measure the TSI.Results:During the trail run, the exercise intensity within the uphill and downhill sections was 94±2% and 91±3% of HRmax, 84±8% and 68±7% of V’O2max, respectively. The oxygen uptake (V’O2) increased within the uphill and decreased within the downhill sections (P< .01). While HR was unaffected by the altering slope conditions, the TSI was inversely correlated to the changes in V’O2 (r = - .70, P< .05).Conclusions:The HR was unaffected by the continuously changing exercise intensity, however, the TSI reflected the alternations in V’O2. Recently used exclusively for scientific purpose, this NIRS based variable may offer a more accurate alternative to HR to monitor running intensity in the future, especially for training and competition in hilly terrain.
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6.
  • Born, Dennis-Peter, et al. (författare)
  • Specialize Early and Select Late : Performance Trajectories of World-Class Finalists and International- and National-Class Swimmers
  • 2024
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 19:2, s. 164-172
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To investigate performance progression from early-junior to peak performance age and compare variety in race distances and swimming strokes between swimmers of various performance levels. Methods: Using a longitudinal data analysis and between-groups comparisons 306,165 annual best times of male swimmers (N = 3897) were used to establish a ranking based on annual best times at peak performance age. Individual performance trajectories were retrospectively analyzed to compare distance and stroke variety. Performances of world-class finalists and international- and national-class swimmers (swimming points: 886 [30], 793 [28], and 698 [28], respectively) were compared across 5 age groups—13–14, 15–16, 17–18, 19–20, and 21+ years—using a 2-way analysis of variance with repeated measures. Results: World-class finalists are not significantly faster than international-class swimmers up to the 17- to 18-year age group (F2|774 = 65, P < .001, η2p=.14) but specialize in short- or long-distance races at a younger age. World-class breaststroke finalists show faster breaststroke times compared to their performance in other swimming strokes from an early age (P < .05), while world-class freestyle and individual medley finalists show less significant differences to their performance in other swimming strokes. Conclusions: While federation officials should aim for late talent selection, that is, not before the 17- to 18-year age group, coaches should aim to identify swimmers’ preferred race distances early on. However, the required stroke variety seems to be specific for each swimming stroke. Breaststroke swimmers could aim for early and strong specialization, while freestyle and individual medley swimmers could maintain large and very large stroke variety, respectively.
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7.
  • Boullosa, DA, et al. (författare)
  • Effectiveness of polarized training for rowing performance
  • 2010
  • Ingår i: International journal of sports physiology and performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 5:4, s. 431-432
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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8.
  • Byrkjedal, Per T., et al. (författare)
  • Association Between Physical Performance Tests and External Load During Scrimmages in Highly Trained Youth Ice Hockey Players
  • 2023
  • Ingår i: International Journal of Sports Physiology and Performance. - Champaign, IL : Human Kinetics. - 1555-0265 .- 1555-0273. ; 18:1, s. 47-54
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: To investigate the relationship between physical performance tests and on-ice external load from simulated games (scrimmages) in ice hockey. METHODS: A total of 14 players completed a physical performance test battery consisting of 30-m sprint test-run and 30-m sprint test-skate (including 10-m split times and maximum speed), countermovement jump, standing long jump, bench press, pull-ups, and trap bar deadlift and participated in 4 scrimmages. External load variables from scrimmages included total distance; peak speed; slow (< 11.0 km/h), moderate (11.0-16.9 km/h), high (17.0-23.9 km/h), and sprint (> 24.0 km/h) speed skating distance; number of sprints; PlayerLoad™; number of high-intensity events (> 2.5 m/s); accelerations; decelerations; and changes of direction. Bayesian pairwise correlation analyses were performed to assess the relationship between physical performance tests and external load performance variables. RESULTS: The results showed strong evidence (Bayes factor > 10) for associations between pull-ups and high-intensity events (τ = .61) and between maximum speed skate and peak speed (τ = .55). There was moderate evidence (Bayes factor >3 to <10) for 6 associations: both maximum speed skate (τ = .44) and countermovement jump (τ = .44) with sprint speed skating distance, countermovement jump with number of sprints (τ = .46), pull-ups with changes of direction (τ = .50), trap bar with peak speed (τ = .45), and body mass with total distance (τ = .49). CONCLUSION: This study found physical performance tests to be associated with some of the external load variables from scrimmages. Nevertheless, the majority of correlations did not display meaningful associations, possibly being influenced by the selection of physical performance tests.
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9.
  • Carlsson, Magnus, et al. (författare)
  • Prediction of race performance of elite cross-country skiers by lean mass
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 9:6, s. 1040-1045
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To investigate the relationship between race performance and lean mass (LM) variables, as well as to examine sex differences in body composition in elite-standard cross-country skiers. Methods: Thirty-four elite cross-country skiers (18 men and 16 women) underwent a dual-emission x-ray absorptiometry body composition test to determine LM, fat mass, and bone mineral content. For both sexes, performance data were collected from a sprint prologue and a distance race. Results: The absolute expression of LM variables [whole body (LMWB), upper body (LMUB), and lower body (LMLB)] was significantly correlated with finishing time in the sprint prologue independent of sex. Distance-race performance was significantly related to LMWB, LMUB, and LMLB in women; however, no correlation was found in men. Men had a significantly higher LM and lower fat mass, independent of expression (absolute or relative), for the whole body, arms, trunk, and legs, except for the absolute fat mass in the trunk. Conclusions: The absolute expressions of LMWB, LMUB, and LMLB were significant predictors of sprint-prologue performance in both sexes, as well as of distance-race performance in women only. Compared with women, male skiers have a higher LM in the body segments that are major contributors to propelling forces. These results suggest that muscle mass in the lower and upper body is equally important for race performance; thus, more focus of elite skiers’ training should be directed to increasing whole-body muscle mass to improve their competitive performance capability.
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10.
  • Carlsson, Magnus, et al. (författare)
  • Time trials predict the competitive performance capacity of junior cross-country skiers
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 12-18
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: This study investigated whether there is a correlation between time-trial performance and competitive performance capacity of male and female junior cross-country skiers and sought to explain sex-specific competitive performance capacity through multiple-regression modeling.Methods: The International Ski Federation's (FIS) junior ranking points for distance (FISdist) and sprint (FISsprint) competitions were used as performance parameters. A total of 38 elite junior (age 18.5 +/- 1.0 y) cross-country skiers (24 men and 14 women) completed 3 time-trial tests: a 3-km level-running time trial (TTRun), a 2-km moderate uphill (1.2 slope) roller-skiing time trial using the double-poling technique (TTDP), and a 2-km uphill (2.8 slope) roller-skiing time trial using the diagonal-stride technique (TTDiag). The correlations were investigated using Pearson correlation analysis, and regression models were created using multiple-linear-regression analysis. Results: For men, FISsprint and FISdist were correlated with the times for TTRun, TTDP, and TTDiag (all P < .001). For women, FISsprint was correlated with the times for TTRun (P < .05), TTDP (P < .01), and TTDiag (P < .01), whereas FISdist was correlated only with the times for TTDP (P < .01) and TTDiag (P < .05). The models developed for FISdist and FISsprint explained 73.9-82.3% of the variance in the performance capacity of male junior cross-country skiers. No statistically valid regression model was found for the women.Conclusions: Running and roller-skiing time trials are useful tests for accurately predicting the performance capacity of junior cross-country skiers.
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11.
  • Cook, C. J., et al. (författare)
  • Improving strength and power in trained athletes with 3 weeks of occlusion training
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 166-172
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To examine the effects of moderate-load exercise with and without blood-flow restriction (BFR) on strength, power, and repeated-sprint ability, along with acute and chronic salivary hormonal parameters. Methods: Twenty male semiprofessional rugby union athletes were randomized to a lower-body BFR intervention (an occlusion cuff inflated to 180 mmHg worn intermittently on the proximal thighs) or a control intervention that trained without occlusion in a crossover design. Experimental sessions were performed 3 times a week for 3 wk with 5 sets of 5 repetitions of bench press, leg squat, and pull-ups performed at 70% of 1-repetition maximum. Results: Greater improvements were observed (occlusion training vs control) in bench press (5.4 ± 2.6 vs 3.3 ± 1.4 kg), squat (7.8 ± 2.1 vs 4.3 ± 1.4 kg), maximum sprint time (-0.03 ± 0.03 vs -0.01 ± 0.02 s), and leg power (168 ± 105 vs 68 ± 50 W). Greater exercise-induced salivary testosterone (ES 0.84-0.61) and cortisol responses (ES 0.65-0.20) were observed after the occlusion intervention sessions compared with the nonoccluded controls; however, the acute cortisol increases were attenuated across the training block. Conclusions: Occlusion training can potentially improve the rate of strength-training gains and fatigue resistance in trained athletes, possibly allowing greater gains from lower loading that could be of benefit during high training loads, in competitive seasons, or in a rehabilitative setting. The clear improvement in bench-press strength resulting from lower-body occlusion suggests a systemic effect of BFR training. © 2014 Human Kinetics, Inc.
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12.
  • Derakhti, Mikael, et al. (författare)
  • Four Weeks of Power Optimized Sprint Training Improves Sprint Performance in Adolescent Soccer Players.
  • 2022
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 17:9, s. 1343-1351
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: This study compared the effects of heavy resisted sprint training (RST) versus unresisted sprint training (UST) on sprint performance among adolescent soccer players.METHODS: Twenty-four male soccer players (age: 15.7 [0.5] y; body height: 175.7 [9.4] cm; body mass: 62.5 [9.2] kg) were randomly assigned to the RST group (n = 8), the UST group (n = 10), or the control group (n = 6). The UST group performed 8 × 20 m unresisted sprints twice weekly for 4 weeks, whereas the RST group performed 5 × 20-m heavy resisted sprints with a resistance set to maximize the horizontal power output. The control group performed only ordinary soccer training and match play. Magnitude-based decision and linear regression were used to analyze the data.RESULTS: The RST group improved sprint performances with moderate to large effect sizes (0.76-1.41) across all distances, both within and between groups (>92% beneficial effect likelihood). Conversely, there were no clear improvements in the UST and control groups. The RST evoked the largest improvements over short distances (6%-8%) and was strongly associated with increased maximum horizontal force capacities (r = .9). Players with a preintervention deficit in force capacity appeared to benefit the most from RST.CONCLUSIONS: Four weeks of heavy RST led to superior improvements in short-sprint performance compared with UST among adolescent soccer players. Heavy RST, using a load individually selected to maximize horizontal power, is therefore highly recommended as a method to improve sprint acceleration in youth athletes.
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13.
  • Dobler, Florian, et al. (författare)
  • Physiological Responses and Performance During a 3-Minute Cycle Time Trial : Standard Paced Versus All-Out Paced
  • 2022
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 17:11, s. 1583-1589
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To compare performance and physiological responses between a standard-paced 3-minute time trial (TTSP, ie, pacing based on normal intention) and a consistently all-out-paced 3-minute time trial (TTAOP). Methods: Sixteen well-trained male cyclists completed the TTSP and TTAOP, on separate days of testing, on a cycling ergometer with power output and respiratory variables measured. Time trials were preceded by 7 x 4-minute submaximal stages of increasing intensity with the linear relationship between power output and metabolic rate used to estimate the contribution from aerobic and anaerobic energy resources. The time course of anaerobic and aerobic contributions to power output was analyzed using statistical parametric mapping. Results: Mean power output was not different between the 2 pacing strategies (TTSP = 417 [43] W, TT Lambda OP = 423 [41] W; P = 0.158). TTAOP resulted in higher peak power output (P < .001), mean ventilation rate (P < .001), mean heart rate (P = .044), peak accumulated anaerobically attributable work (P = .026), post-time-trial blood lactate concentration (P = .035), and rating of perceived exertion (P = .036). Statistical parametric mapping revealed a higher anaerobic contribution to power output during the first similar to 30 seconds and a lower contribution between similar to 90 and 170 seconds for TT Lambda OP than TTSP. The aerobic contribution to power output was higher between -55 and 75 seconds for TT Lambda OP. Conclusions: Although there was no significant difference in performance (ie, mean power output) between the 2 pacing strategies, differences were found in the distribution of anaerobically and aerobically attributable power output. This implies that athletes can pace a 3-minute maximal effort very differently but achieve the same result.
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14.
  • Dunst, Anna Katharina, et al. (författare)
  • A Novel Approach to Determining the Alactic Time Span in Connection with Assessment of the Maximal Rate of Lactate Accumulation in Elite Track Cyclists
  • 2023
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 18:2, s. 157-163
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Following short-term all-out exercise, the maximal rate of glycolysis is frequently assessed on the basis of the maximal rate of lactate accumulation in the blood. Since the end of the interval without significant accumulation (talac) is 1 of 2 denominators in the calculation employed, accurate determination of this parameter is crucial. Although the very existence and definition of talac, as well as the validity of its determination as time-to-peak power (tPpeak), remain controversial, this parameter plays a key role in anaerobic diagnostics. Here, we describe a novel approach to determination of talac and compare it to the current standard. Methods: Twelve elite track cyclists performed 3 maximal sprints (3, 8, and 12 s) and a high-rate, low-resistance pedaling test on an ergometer with monitoring of crank force and pedaling rate. Before and after each sprint, capillary blood samples were taken for determination of lactate accumulation. Fatigue-free force–velocity and power–velocity profiles were generated. talac was determined as tPpeak and as the time point of the first systematic deviation from the force–velocity profile (tFf). Results: Accumulation of lactate after the 3-second sprint was significant (0.58 [0.19] mmol L−1; P < .001, d = 1.982). tFf was <3 seconds and tPpeak was ≥3 seconds during all sprints (P < .001, d = − 2.111). Peak power output was lower than maximal power output (P < .001, d = −0.937). Blood lactate accumulation increased linearly with increasing duration of exercise (R2 ≥ .99) and intercepted the x-axis at ∼tFf. Conclusion: Definition of talac as tPpeak can lead to incorrect conclusions. We propose determination of talac based on tFf, the end of the fatigue-free state that may reflect the beginning of blood lactate accumulation.
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15.
  • Fabré, Nicolas, et al. (författare)
  • A novel approach for lactate threshold assessment based on rating of perceived exertion
  • 2013
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 8:3, s. 263-270
  • Tidskriftsartikel (refereegranskat)abstract
    • This study tested the hypothesis that the DMAX (for maximal distance) method could be applied to ratings of perceived exertion (RPE), to propose a novel method for individual detection of the lactate threshold (LT) using RPE alone during an incremental test to exhaustion. Twenty-one participants performed an incremental test on a cycle ergometer. At the end of each stage, lactate concentration was measured and the participants estimated RPE using the Borg CR100 scale. The intensity corresponding to the fixed lactate values of 2 or 4 mmol • L-1 (2mM and 4mM), the ventilatory threshold (VT), the respiratory-compensation point (RCP), and the instant of equality of pulmonary gas exchange (RER=1.00) were determined. Lactate (DMAX La) and RPE (DMAX RPE) thresholds were determined using the DMAX method. Oxygen uptake (VO2), heart rate, and power output measured at DMAX RPE and at D MAX La were not statistically different. Bland-Altman plots showed small bias and good agreements when DMAX RPE was compared with the DMAX La and RER=1.00 methods (bias = -0.05% and -2% of VO2max, respectively). Conversely, VO2 from the D MAX RPE method was lower than VO2 at 4 mM and at RCP and was higher than VO2 at 2 mM and at VT. VO2 at D MAX RPE was strongly correlated with VO2 at D MAX La (r = .97), at RER=1.00 (r = .97), at 2 mM (r = .85), at 4 mM (r = .93), at VT (r = .95), and at RCP (r = .95). The combination of the DMAX method with the RPE responses permitted precise and individualized estimates of LT using the DMAX method.
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16.
  • Fornasiero, Alessandro, et al. (författare)
  • Analysis of Sprint Ski Mountaineering Performance
  • 2024
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 19:2, s. 155-163
  • Tidskriftsartikel (refereegranskat)
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17.
  • Fullagar, Hugh H. K., et al. (författare)
  • The Time Course of Perceptual Recovery Markers After Match Play in Division I-A College American Football
  • 2017
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 12:9, s. 1264-1266
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To investigate the recovery time course of customized wellness markers (sleep, soreness, energy, and overall wellness) in response to match play in American Division I-A college football players. Methods: A retrospective research design was used. Wellness data were collected and analyzed for 2 American college football seasons. Perceptions of soreness, sleep, energy, and overall wellness were obtained for the day before each game (GD-1) and the days after each game (GD+2, GD+3, and GD+4). Standardized effect-size (ES) analyses +/- 90% confidence intervals were used to interpret the magnitude of the mean differences between all time points for the start, middle, and finish of the season, using the following qualitative descriptors: 0-0.19 trivial, 0.2-0.59 small, 0.6-1.19 moderate, 1.2-1.99 large, <2.0 very large. Results: Overall wellness showed small ES reductions on GD+2 (d = 0.22 +/- 0.09, likely [94.8%]), GD+3 (d = 0.37 +/- 0.15, very likely), and GD+4 (d = 0.29 +/- 0.12, very likely) compared with GD-1. There were small ES reductions for soreness between GD-1 and GD+2, GD+3, and GD+4 (d = 0.21 +/- 0.09, likely, d = 0.29 +/- 0.12, very likely, and 0.30 +/- 0.12, very likely, respectively). Small ES reductions were also evident between GD-1 and GD+3 (d = 0.21 +/- 0.09, likely) for sleep. Feelings of energy showed small ESs on GD+3 (d = 0.27 +/- 0.11, very likely) and GD+4 (d = 0.22 +/- 0.09, likely) compared with GD-1. Conclusion: All wellness markers were likely to very likely worse on GD+3 and GD+4 than on GD-1. These findings show that perceptual wellness takes longer than 4 d to return to pregame levels and thus should be considered when prescribing training and/or recovery.
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18.
  • Garland, Stephen, 1973-, et al. (författare)
  • Effect of Blood Lactate Sample Site and Test Protocol on Training Zone Prescription in Rowing
  • 2008
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 3:3, s. 347-358
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose:To assess the effect of sample site (earlobe vs toe) and incremental exercise protocol (continuous vs discontinuous) on training zone prescription in rowing.Methods:Twenty-six rowers performed two incremental exercise tests on an ergometer: (1) a five-step discontinuous test with 4-min stages and 30-W increment, with blood samples taken from the earlobe and toe at the start of the 1-min break between steps; (2) a continuous test, with 2-min stages and 30-W increment, with blood samples taken from the right first toe at the end of each stage. Blood was analyzed for lactate concentration.Results:At a lactate concentration of 2 mmol·L−1, the mean (95% CI) power output was 8.1 (± 15.4) W greater for the continuous protocol, the random error between the methods (1.96 × SD of differences) was ± 58.8 W, and there was no evidence of any relationship between power output and error between methods. At a lactate concentration of 4 mmol·L−1, the mean (95% CI) power output was 24.2 (± 17.0) W greater for the continuous protocol, and the random error was ± 64.8 W. At 4 mmol·L−1, systematic bias between methods increased with high power outputs.Conclusions:The continuous protocol with toe sampling led to higher power outputs for a given lactate concentration compared with the discontinuous protocol with earlobe sampling. This was partly due to the choice of sample site and largely due to the choice of protocol. This bias, and also random variability, makes direct comparison of these tests inappropriate.
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19.
  • Govus, Andrew D., et al. (författare)
  • Relationship between pretraining subjective wellness measures, player load, and rating-of-perceived-exertion training load in American college football
  • 2018
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 13:1, s. 95-101
  • Tidskriftsartikel (refereegranskat)abstract
    • Context: The relationship between pretraining subjective wellness and external and internal training load in American college football is unclear. Purpose: To examine the relationship of pretraining subjective wellness (sleep quality, muscle soreness, energy, wellness Z score) with player load and session rating of perceived exertion (s-RPE-TL) in American college football players. Methods: Subjective wellness (measured using 5-point, Likert-scale questionnaires), external load (derived from GPS and accelerometry), and s-RPE-TL were collected during 3 typical training sessions per week for the second half of an American college football season (8 wk). The relationship of pretraining subjective wellness with player load and s-RPE training load was analyzed using linear mixed models with a random intercept for athlete and a random slope for training session. Standardized mean differences (SMDs) denote the effect magnitude. Results: A 1-unit increase in wellness Z score and energy was associated with trivial 2.3% (90% confidence interval [CI] 0.5, 4.2; SMD 0.12) and 2.6% (90% CI 0.1, 5.2; SMD 0.13) increases in player load, respectively. A 1-unit increase in muscle soreness (players felt less sore) corresponded to a trivial 4.4% (90% CI ?8.4, ?0.3; SMD ?0.05) decrease in s-RPE training load. Conclusion: Measuring pretraining subjective wellness may provide information about players’ capacity to perform in a training session and could be a key determinant of their response to the imposed training demands American college football. Hence, monitoring subjective wellness may aid in the individualization of training prescription in American college football players.
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20.
  • Hanstock, Helen, 1989-, et al. (författare)
  • Influence of Immune and Nutritional Biomarkers on Illness Risk During Interval Training
  • 2020
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 15:1, s. 60-67
  • Tidskriftsartikel (refereegranskat)abstract
    • Intensive training periods may negatively influence immune function, but the immunological consequences of specific high-intensity training (HIT) prescriptions are not well defined. Purpose: This study explored whether three different HIT prescriptions influence multiple health-related biomarkers and whether biomarker responses to HIT were associated with upper respiratory illness (URI) risk. Methods: Twenty-five male cyclists and triathleteswere randomised to three HIT groups and completed twelve HIT sessions over four weeks. Peak oxygen consumption (V̇O2peak) was determined using an incremental cycling protocol, while resting serum biomarkers (cortisol, testosterone, 25(OH)D and ferritin), salivary immunoglobulin-A (s-IgA) and energy availability (EA) were assessed before and after the training intervention. Participants self-reported upper respiratory symptoms during the interventionand episodes of URI were identified retrospectively. Results: Fourteen athletes reported URIs, but there were no differences in incidence, duration or severity between groups. Increased risk of URI was associated with higher s-IgA secretion rates (odds ratio=0.90, 90% CI:0.83-0.97). Lower pre-intervention cortisol and higher EA predicted a 4% increase in URI duration. Participants with higher V̇O2peak reported higher total symptom scores (incidence rate ratio=1.07, 90% CI:1.01-1.13). Conclusions: Although multiple biomarkers wereweakly associated with risk of URI, the direction of associations between s-IgA, cortisol, EA and URI risk were inverse to previous observations and physiological rationale. There was a cluster of URIs within the first week of the training intervention, but no samples were collected at this time-point. Future studies should incorporate more frequent sample time-points, especially around the onset of new training regimes, and include athletes with suspected or known nutritional deficiencies.
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21.
  • Hébert-Losier, Kim, et al. (författare)
  • Jumping and hopping in elite and amateur orienteering athletes and correlations to sprinting and running
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 9:6, s. 993-999
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE:Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening-cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlations with sprinting and/or running have been examined in orienteering athletes.METHODS:The authors investigated squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), and hopping performed by 8 elite and 8 amateur male foot-orienteering athletes (29 ± 7 y, 183 ± 5 cm, 73 ± 7 kg) and possible correlations to road, path, and forest running and sprinting performance, as well as running economy, velocity at anaerobic threshold, and peak oxygen uptake (VO(2peak)) from treadmill assessments.RESULTS:During SJs and CMJs, elites demonstrated superior relative peak forces, times to peak force, and prestretch augmentation, albeit lower SJ heights and peak powers. Between-groups differences were unclear for CMJ heights, hopping stiffness, and most SLJ parameters. Large pairwise correlations were observed between relative peak and time to peak forces and sprinting velocities; time to peak forces and running velocities; and prestretch augmentation and forest-running velocities. Prestretch augmentation and time to peak forces were moderately correlated to VO(2peak). Correlations between running economy and jumping or hopping were small or trivial.CONCLUSIONS:Overall, the elites exhibited superior stretch-shortening-cycle utilization and rapid generation of high relative maximal forces, especially vertically. These functional measures were more closely related to sprinting and/or running abilities, indicating benefits of lower-body training in orienteering.
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22.
  • Hernandez-Sanchez, S, et al. (författare)
  • Ultraendurance Exercise in a Renal Transplant Recipient: A Case Study
  • 2020
  • Ingår i: International journal of sports physiology and performance. - : Human Kinetics. - 1555-0273 .- 1555-0265. ; 15:7, s. 1039-1042
  • Tidskriftsartikel (refereegranskat)abstract
    • Context: Exercise improves the commonly impaired physical fitness and cardiovascular health of transplant recipients. However, concerns remain about the safety of strenuous physical exercise in this population. Purpose: To describe the physiological effects of ultraendurance exercise in a renal transplant recipient. Methods: After a 25-week training program, a 31-year-old male with stage 3 chronic kidney disease who had undergone 2 kidney transplants participated in a 62-km (5600 m of positive altitude change) trail-running race. Blood and urine analyses were performed at baseline (24 h before the race), 4 days after the race, and at different time points up to 16 weeks postexercise. Results: The participant completed the race in 12 hours 18 minutes. No noticeable side effects were recorded during the whole study period, including the prerace training program. No major urine or blood alterations were observed after ultraendurance exercise, with glomerular filtration rate remaining steady during the study period. Conclusions: Ultraendurance exercise induced no adverse physiological effects in a well-trained young renal transplant recipient.
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23.
  • Ihalainen, Johanna K., et al. (författare)
  • Body composition, energy availability, training, and menstrual status in female runners
  • 2021
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 16:7, s. 1043-1048
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), amenorrheic (AME), and eumenorrheic (EUM) ATH. Correlations to injury, illness, and performance were also examined. Methods: 13 ATH and 8 CON completed the Low Energy Availability in Females Questionnaire. Anthropometric, energy intake, and peak oxygen uptake assessments were made at 4 time points throughout the year: at baseline post competition season, post general preparation, post-specific preparation, and post competition season the following year. Logs of physical activity, menstrual cycle, illness, and injury were kept by all participants. Performance was defined using the highest International Association of Athletics Federations points prior to and after the study. Results: ATH had significantly lower body mass (P=.008), fat percentage (P<.001), and body mass index (P=.027) compared with CON, while energy availability did not differ between ATH and CON. The Low Energy Availability in Females Questionnaire score was higher in ATH than in CON (P=.028), and 8 ATH (vs zero CON) were AME. The AME had significantly more injury days (P=.041) and ran less (P=.046) than EUM, while total annual running distance was positively related to changes in performance in ATH (r=.62, P=.043, n=11). Conclusions: More than half of this group of runners was AME, and they were injured more and ran less than their EUM counterparts. Furthermore, only the EUM runners increased their performance over the course of the year.
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24.
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25.
  • Jones, Thomas W., et al. (författare)
  • An Analysis of Warm-Up Strategies at a Cross-Country Skiing National Championship
  • 2022
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 17:1, s. 50-57
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To provide a descriptive analysis of the warm-up (WU) strategies employed by cross-country skiers prior to distance and sprint competitions at a national championship and to compare the skiers' planned and executed WUs prior to the respective competitions.Methods: Twenty-one national- and international-level skiers (11 women and 10 men) submitted WU plans prior to the distance and sprint competitions, and after the competitions, reported any deviations from the plans. Skiers used personal monitors to record heart rate (HR) during WU, races, and cooldown. Quantitative statistical analyses were conducted on WU durations, durations in HR-derived intensity zones, and WU loads. Qualitative analyses were conducted on skiers' WU plans and their reasons for deviating from the plans.Results: Skiers' planned WUs were similar in content and planned time in HR-derived intensity zones for both the distance and sprint competitions. However, 45% of the women and 20% of the men reported that their WU was not carried out as planned, with reasons detailed as being due to incorrect intensities and running out of time. WU activities including skiing across variable terrain, muscle-potentiating exercises, and heat-maintenance strategies were missing from the skiers' planned routines.Conclusions: Skiers favored a long, traditional WU approach for both the sprint and distance events, performing less high-intensity and more moderate-intensity exercise during their WUs than planned. In addition, elements likely relevant to successful performance in cross-country skiing were missing from WU plans.
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26.
  • Jones, Thomas W., et al. (författare)
  • Using Multivariate Data Analysis to Project Performance in Biathletes and Cross-Country Skiers
  • 2023
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 18:8, s. 840-851
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To determine whether competitive performance, as defined by International Biathlon Union (IBU) and International Ski Federation (FIS) points in biathlon and cross-country (XC) skiing, respectively, can be projected using a combination of anthropometric and physiological metrics. Shooting accuracy was also included in the biathlon models. Methods: Data were analyzed using multivariate methods from 45 (23 female and 22 male) biathletes and 202 (86 female and 116 male) XC skiers who were all members of senior national teams, national development teams, or ski-university or high school invite-only programs (age range: 16-36 y). Anthropometric and physiological characteristics were assessed via dual-energy X-ray absorptiometry and incremental roller-ski treadmill tests, respectively. Shooting accuracy was assessed via an outdoor standardized testing protocol. Results: Valid projective models were identified for female biathletes' IBU points (R2 = .80/ Q2 = .65) and female XC skiers' FIS distance (R2 = .81/Q2 = .74) and sprint (R2 = .81/Q2 = .70) points. No valid models were identified for the men. The most important variables for the projection of IBU points were shooting accuracy, speeds at blood lactate concentrations of 4 and 2 mmol center dot L-1, peak aerobic power, and lean mass. The most important variables for the projection of FIS distance and sprint points were speeds at blood lactate concentrations of 4 and 2 mmol center dot L-1 and peak aerobic power. Conclusions: This study highlights the relative importance of specific anthropometric, physiological, and shooting-accuracy metrics in female biathletes and XC skiers. The data can help to identify the specific metrics that should be targeted when monitoring athletes' progression and designing training plans.
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27.
  • Lanferdini, Fábio J, et al. (författare)
  • Differences in Pedaling Technique in Cycling : A Cluster Analysis.
  • 2016
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 11:7, s. 959-964
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (POVT2) compared with cycling at their maximal power output (POMAX).METHODS: Twenty athletes performed an incremental cycling test to determine their power output (POMAX and POVT2; first session), and pedal forces, muscle activation, muscle-tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in POMAX and POVT2. Athletes were assigned to 2 clusters based on the behavior of outcome variables at POVT2 and POMAX using cluster analysis.RESULTS: Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle-tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at POVT2 vs POMAX, cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length.CONCLUSIONS: Increases in power output lead to greater variations in knee angle, muscle-tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.
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28.
  • Lucia, A, et al. (författare)
  • Elite athletes: are the genes the champions?
  • 2010
  • Ingår i: International journal of sports physiology and performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 5:1, s. 98-102
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent research has analyzed the genetic factors that influence world-class athletic status. Much of what we know comes from association studies, with the ACE I/D and ACTN3 R577X polymorphisms having been extensively studied. The association between the ACTN3 R577X variation and elite athlete status in power sports is strongly documented, yet whether the current body of knowledge on other variants can be extrapolated to athletic champion status remains to be determined. Athletic champion status is a complex polygenic trait in which numerous candidate genes, complex gene–gene interactions, and environment–gene interactions are involved. Besides the need for more studies and new approaches taking into account the complexity of the problem, we believe that factors beyond genetic endowment are likely to have a stronger influence in the attainment of athletic champion status.
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29.
  • Matzka, Manuel, et al. (författare)
  • Comparison of Physiological Parameters During On-Water and Ergometer Kayaking and Their Relationship to Performance in Sprint Kayak Competitions
  • 2021
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 16:7, s. 958-964
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: (1) To compare various physiological indicators of performance during a 5 x 1500-nt incremental kayak test performed on an ergometer and on-water and (2) to analyze the relationships between these indicators and the actual competition performance of elite sprint kayakers, aiming to provide information to coaches for evaluating and planning training on-water. Methods: A total of 14 male and female German elite sprint kayakers performed an incremental test both on an ergometer and onwater. The tissue saturation index of the musculus (m.) biceps brachii, oxygen consumption, ratings of perceived exertion, and levels of blood lactate were measured and compared with actual racing times. In addition, power output was monitored during ergometer testing only. Results: Oxygen consumption during the fourth (P = .02; d = 0.32) and final (fifth; P < .001; d= 0.32) steps of incremental testing was higher on-water than on the ergometer. The tissue saturation index of the m. biceps brachii was approximately 21% higher at the end of the ergometer test (P = .002; d = 1.14). During the second (P = .01; d = 0.78), third (P = .005; d = 0.93), and fourth stages (P = .005; d = 1.02), the ratings of perceived exertion for ergometer kayaking was higher. During the final step, power output was most closely correlated to 200- (r = .88), 500- (r = .93). and 1000-m (r = .86) racing times (all Ps <.01). Conclusions: During high-intensity kayaking on an ergometer or on-water, the oxygen consumption and tissue saturation index of the m. biceps brachii differ. Furthermore, at moderate to submaximal intensities, the ratings of perceived exertion were higher for ergometer than for on-water kayaking. Finally, of all parameters assessed, the power output during ergometer kayaking exhibited the strongest correlation with actual racing performance.
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30.
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31.
  • McGawley, Kerry, 1978-, et al. (författare)
  • Aerobic and anaerobic contributions to energy production among junior male and female cross-country skiers during diagonal skiing
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 32-40
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Cross-country-ski races place complex demands on athletes, with events lasting between approximately 3 min and 2 h. The aim of the current study was to compare the aerobic and anaerobic measures derived from a short time trial (TT) between male and female skiers using diagonal cross-country skiing. Methods: Twenty-four highly trained cross-country skiers (12 male and 12 female, age 17.4 ± 1.4 y, body mass 68.2 ± 8.9 kg, height 174 ± 8 cm) participated. The submaximal VO2–speed relationship and VO2max were derived from an incremental ramp test to exhaustion (RAMP), while the accumulated oxygen deficit (AOD), peak VO2, and performance time were measured during a 600-m TT. Results: The female skiers took longer to complete the TT than the males (209 ± 9 s vs 166 ± 7 s, P < .001) and exhibited a lower relative anaerobic contribution (20% ± 4% vs 24% ± 3%, P = .015) and a higher fractional utilization of VO2max (84% ± 4% vs 79% ± 5%, P = .007) than males. Although there was no significant difference in AOD between the sexes (40.9 ± 9.5 and 47.3 ± 7.4 mL/kg for females and males, respectively; P = .079), the mean difference ± 90% confidence intervals of 6.4 ± 6.0 mL/kg reflected a likely practical difference (ES = 0.72). The peak VO2 during the TT was significantly higher than VO2max during the RAMP for all participants combined (62.3 ± 6.8 vs 60.5 ± 7.2 mL/kg/min, P = .011), and the mean difference ± 90% confidence intervals of 1.8 ± 1.1 mL/kg reflected a possible practical difference (ES = 0.25). Conclusions: These results show that performance and physiological responses to a self-paced TT lasting approximately 3 min differ between sexes. In addition, a TT may provide a valid measure of VO2max.
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32.
  • McGawley, Kerry, 1978-, et al. (författare)
  • Comparing active, passive and combined warm-ups among junior alpine skiers in -7°C
  • 2021
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 16:8, s. 1140-1147
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Warming up in very cold climates and maintaining an elevated body temperature prior to a race is challenging for snow-sport athletes. This study aimed to investigate the effects of active (ACT), passive (PAS) and a combination of ACT and PAS (COM) warm-ups on maximal physical performance in a sub-zero environment. Methods: Ten junior alpine skiers completed three experimental trials in -7.2 ± 0.2°C. ACT involved 5-min of moderate cycling, 3 x 15-s accelerations, a 6-s sprint, five counter-movement jumps (CMJs) and a 10-min passive transition phase, while in PAS participants wore a lower-body heated garment for 24 min. In COM participants completed the active warm-up, then wore the heated garment during the transition phase. Two maximal CMJs and a 90-s maximal isokinetic cycling test followed the warm-up. Results: CMJ performance was likely (P=0.150) and very likely (P=0.013) greater in ACT and COM, respectively, versus PAS. Average power output during the cycling test was likely (P=0.074) greater in ACT and COM versus PAS. Participants felt likely to almost certainly warmer (P<0.01) and more comfortable (P=0.161) during ACT and COM versus PAS. In addition, participants felt likely warmer (P=0.136) and very likely more comfortable (P=0.161) in COM versus ACT. Conclusions: COM resulted in significantly improved CMJ performance versus PAS, while both ACT and COM led to likely improved 90-s cycling performance. Participants felt significantly warmer during ACT and COM versus PAS, and likely warmer in COM versus ACT. Therefore, a combined warm-up is recommended for alpine skiers performing in sub-zero temperatures.
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33.
  • Mourot, Laurent, et al. (författare)
  • Cross-Country Skiing and Postexercise Heart-Rate Recovery
  • 2015
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 10:1, s. 11-16
  • Tidskriftsartikel (refereegranskat)abstract
    • Postexercise heart-rate (HR) recovery (HRR) indices have been associated with running and cycling endurance-exercise performance. The current study was designed (1) to test whether such a relationship also exists in the case of cross-country skiing (XCS) and (2) to determine whether the magnitude of any such relationship is related to the intensity of exercise before obtaining HRR indices. Ten elite male cross-country skiers (mean +/- SD; 28.2 +/- 5.4 y, 181 +/- 8 cm, 77.9 +/- 9.4 kg, 69.5 +/- 4.3 mL.min(-1) . kg(-1) maximal oxygen uptake [VO2max]) performed 2 sessions of roller-skiing on a treadmill: a 2 x 3-km time trial and the same 6-km at an imposed submaximal speed followed by a final 800-m time trial. VO2 and HR were monitored continuously, while HRR and blood lactate (BLa) were assessed during 2 min immediately after each 6-km and the 800-m time trial. The 6-km time-trial time was largely negatively correlated with VO2max and BLa. On the contrary, there was no clear correlation between the 800-m time-trial time and VO2, HR, or BLa. In addition, in no case was any clear correlation between any of the HRR indices and performance time or VO2max observed. These findings confirm that XCS performance is largely correlated with VO2max and the ability to tolerate high levels of BLa; however, postexercise HRR showed no clear association with performance. The homogeneity of the group of athletes involved and the contribution of the arms and upper body to the exercise preceding determination of HRR may explain this absence of a relationship.
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34.
  • Mourot, Laurent, et al. (författare)
  • Second Ventilatory Threshold From Heart-Rate Variability : Valid When the Upper Body Is Involved?
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:4, s. 695-701
  • Tidskriftsartikel (refereegranskat)abstract
    • To determine the most accurate method based on spectral analysis of heart-rate variability (SA-HRV) during an incremental and continuous maximal test involving the upper body, the authors tested 4 different methods to obtain the heart rate (HR) at the second ventilatory threshold (VT2). Sixteen ski mountaineers (mean +/- SD; age 25 +/- 3 y, height 177 +/- 8 cm, mass 69 +/- 10 kg) performed a roller-ski test on a treadmill. Respiratory variables and HR were continuously recorded, and the 4 SA-HRV methods were compared with the gas-exchange method through Bland and Altman analyses. The best method was the one based on a time-varying spectral analysis with high frequency ranging from 0.15 Hz to a cutoff point relative to the individual's respiratory sinus arrhythmia. The HR values were significantly correlated (r(2) = .903), with a mean HR difference with the respiratory method of 0.1 +/- 3.0 beats/min and low limits of agreements (around -6 /+ 6 beats/min). The 3 other methods led to larger errors and lower agreements (up to 5 beats/min and around -23/+ 20 beats/min). It is possible to accurately determine VT2 with an HR monitor during an incremental test involving the upper body if the appropriate HRV method is used.
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35.
  • Nilsson, Johnny, 1950-, et al. (författare)
  • Contribution of leg muscle forces to paddle force and kayak speed during maximal effort flat-water paddling
  • 2016
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 11:1, s. 22-27
  • Tidskriftsartikel (refereegranskat)abstract
    • The purpose was to investigate the contribution of leg-muscle-generated forces to paddle force and kayak speed during maximal-effort flat-water paddling. Five elite male kayakers at national and international level participated. The participants warmed up at progressively increasing speeds and then performed a maximal-effort, nonrestricted paddling sequence. This was followed after 5 min rest by a maximal-effort paddling sequence with the leg action restricted—the knee joints “locked.” Left- and right-side foot-bar and paddle forces were recorded with specially designed force devices. In addition, knee angular displacement of the right and left knees was recorded with electrogoniometric technique, and the kayak speed was calculated from GPS signals sampled at 5 Hz. The results showed that reduction in both push and pull foot-bar forces resulted in a reduction of 21% and 16% in mean paddle-stroke force and mean kayak speed, respectively. Thus, the contribution of foot-bar force from lower-limb action significantly contributes to kayakers’ paddling performance.
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36.
  • Nilsson, Johnny E, et al. (författare)
  • New Devices for Measuring Forces on the Kayak Foot-Bar and on the Seat During Flat-Water Kayak Paddling : a technical report.
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 9:2, s. 365-70
  • Tidskriftsartikel (refereegranskat)abstract
    • The purpose was to develop and validate portable force-measurement devices for recordings of push and pull forces applied by each foot to the foot-bar of a kayak, and the horizontal force at the seat. A foot-plate on a single-point force transducer mounted on the kayak foot-bar underneath each foot allowed the push and pull forces to be recorded. Two metal frames interconnected with four linear ball-bearings and a force transducer allowed recording of horizontal seat force. The foot-bar force device was calibrated by loading each foot plate with weights in the push pull direction perpendicular to the foot plate surface while the seat force device was calibrated to horizontal forces with and without weights on the seat. A strong linearity (r2=0.99-1.0) was found between transducer output signal and load force in the push and pull directions for both foot-bar transducers perpendicular to the foot plate and the seat-force measuring device. Reliability of both devices was tested by means of a test-retest design. The coefficient of variation (CV) for foot-bar push and pull forces ranged from 0.1 to 1.1% and the CV for the seat forces varied between 0.6 - 2.2%. The present study opens up for new investigations of the forces generated within the kayak and ways to optimize kayak paddling performance.
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37.
  • Osborne, John O., et al. (författare)
  • Annual Volume and Distribution of Physical Training in Norwegian Female Cross-Country Skiers and Biathletes : A Comparison Between Sports, Competition Levels, and Age Categories- The FENDURA Project
  • 2024
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 19:1, s. 19-27
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To describe and compare the annual physical training characteristics between Norwegian female cross-country (XC) skiers and biathletes across competition levels and age categories. Methods: Daily training sessions for 1 year were recorded for 45 XC skiers and 26 biathletes, comprising international/national team (inter[national]) and nonnational/regional team members (nonnational) of both junior and senior age. Endurance, strength, flexibility, speed, and power training sessions were recorded. Data included exercise modality, intensity, and duration. Data were analyzed using linear mixed-effects models. Results: The total annual physical training volume consisted of -90% endurance training for both groups, although XC skiers had significantly higher total volumes (-10%; P = .003; d= 0.78) than biathletes. Senior XC skiers performed more training hours of skiing and/or roller skiing compared with biathletes over the season. However, biathletes compensated for this lower volume by more skating and a higher proportion of endurance training as skiing (81% [17%]) compared with XC skiers (68% [16%]; P < .001; d= 0.94). Overall, (inter)national-level athletes completed a higher annual training volume than non-national-level athletes (740 [90] h vs 649 [95] h; P= .004;d = 0.81). Although juniors reported less endurance volume than seniors, they maintained a relatively stable level of endurance training across the preparatory and competition period, unlike senior athletes. Conclusions: The higher annual physical training volume by XC skiers compared with biathletes is likely caused by the different demands of the 2 sports; XC skiing necessitates training for 2 skiing styles, while biathlon requires additional shooting practice. However, biathletes compensate with a higher proportion of ski training, particularly in the skating technique.
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38.
  • Sandbakk, Oyvind, et al. (författare)
  • A Reappraisal of Success Factors for Olympic Cross-Country Skiing.
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 117-121
  • Tidskriftsartikel (refereegranskat)abstract
    • Cross-country skiing has been an Olympic event since the first Winter Games in Chamonix in 1924. Due to more effective training and tremendous improvements in equipment and track preparation, the speed of Olympic cross-country ski races has increased more than that of any other Olympic endurance sport. Moreover, pursuit, mass-start and sprint races have been introduced. Indeed, ten of the twelve current Olympic competitions in cross-country skiing involve mass-starts, in which tactics play a major role and the outcome is often decided in the final sprint. Accordingly, reappraisal of the success factors for performance in this context is required. The very high aerobic capacity (VO2max) of many of today's world-class skiers is similar that of their predecessors. At the same time, the new events provide more opportunities to profit from anaerobic capacity, upper-body power, high-speed techniques and "tactical flexibility". The wide range of speeds and slopes involved in cross-country skiing require skiers to continuously alternate between and adapt different sub-techniques during a race. This technical complexity places a premium on efficiency. The relative amounts of endurance training performed at different levels of intensity have remained essentially constant during the past four decades. However, in preparation for the Sochi Olympics in 2014 cross-country skiers are performing more endurance training on roller skis on competition-specific terrain, placing greater focus on upper-body power and more systematically perform strength training and skiing at high speeds than previously.
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39.
  • Sandbakk, Oyvind, et al. (författare)
  • Sex Differences in World Record Performance : The Influence of Sport Discipline and Competition Duration
  • 2018
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 13:1, s. 2-8
  • Tidskriftsartikel (refereegranskat)abstract
    • In the present review, we summarize scientific knowledge concerning sex differences in world record performance and the influence of sport discipline and competition duration. In addition, we discuss how physiological factors relate to sex dimorphism. While cultural factors played a major role in the rapid improvement of performance of women relative to men up until the 1990’s, sex differences between the world’s best athletes in most events have remained relatively stable at approximately 8-12%. The exceptions are events in which upper-body power is a major contributor, where this difference is more than 12%, and ultra-endurance swimming, where the gap is now less than 5%. The physiological advantages in men include a larger body size with more skeletal muscle mass, a lower percentage of body fat, as well as greater maximal delivery of anaerobic and aerobic energy. The greater strength and anaerobic capacity in men normally disappears when normalized for fat-free body mass, whereas the higher hemoglobin concentrations leads to 5-10% greater maximal oxygen uptakes in men also with such normalization. The higher percentage of muscle mass in the upper-body of men results in a particularly large sex difference in power production during upper-body exercise. While the exercise efficiency of men and women is usually similar, women have a better capacity to metabolize fat and demonstrate better hydrodynamics and more even pacing, which may be advantageous in particular during long-lasting swimming competitions.
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40.
  • Sandbakk, Øyvind, et al. (författare)
  • Physiological Capacity and Training Routines of Elite Cross-Country Skiers : Approaching the Upper Limits of Human Endurance
  • 2017
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 12:8, s. 1003-1011
  • Forskningsöversikt (refereegranskat)abstract
    • Cross-country (XC) skiing is one of the most demanding of endurance sports, involving protracted competitions on varying terrain employing a variety of skiing techniques that require upper- and/or lower-body work to different extents. Through more effective training and extensive improvements in equipment and track preparation, the speed of cross-country ski races has increased more than that of any other winter Olympic sport, and, in addition, new types of racing events have been introduced. To a certain extent this has altered the optimal physiological capacity required to win, and the training routines of successful skiers have evolved accordingly. The long-standing tradition of researchers working closely with XC-ski coaches and athletes to monitor progress, improve training, and refine skiing techniques has provided unique physiological insights revealing how these athletes are approaching the upper limits of human endurance. This review summarizes current scientific knowledge concerning the demands involved in elite XC skiing, as well as the physiological capacity and training routines of the best athletes.
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41.
  • Sandbakk, Øyvind, et al. (författare)
  • The Evolution of World-Class Endurance Training: The Scientist's View on Current and Future Trends
  • 2023
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 18:8, s. 885-889
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Elite sport is continuously evolving. World records keep falling and athletes from a longer list of countries are involved.Purpose: This commentary was designed to provide insights into present and future trends associated with world-class endurance training based on the perspectives, experience, and knowledge of an expert panel of 25 applied sport scientists.Results: The key drivers of development observed in the past 10-15 years were related to (1) more accessible scientific knowledge for coaches and athletes combined with (2) better integration of practical and scientific exchange across multidisciplinary perspectives within professionalized elite athlete support structures, as well as (3) utilization of new technological advances. Based on these perspectives, we discerned and exemplified the main trends in the practice of endurance sports into the following categories: better understanding of sport-specific demands; improved competition execution; larger, more specific, and more precise training loads; improved training quality; and a more professional and healthier lifestyle. The main areas expected to drive future improvements were associated with more extensive use of advanced technology for monitoring and prescribing training and recovery, more precise use of environmental and nutritional interventions, better understanding of athlete- equipment interactions, and greater emphasis on preventing injuries and illnesses.Conclusions: These expert insights can serve as a platform and inspiration to develop new hypotheses and ideas, encourage future collaboration between researchers and sport practitioners, and, perhaps most important, stimulate curiosity and further collaborative studies about the training, physiology, and performance of endurance athletes.
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42.
  • Sandbakk, Ø., et al. (författare)
  • The velocity and energy profiles of elite cross-country skiers executing downhill turns with different radii
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 41-47
  • Tidskriftsartikel (refereegranskat)abstract
    • This study examined the influence of turn radius on velocity and energy profiles when skidding and step turning during more and less effective downhill turns while cross-country skiing. Thirteen elite female cross-country skiers performed single turns with a 9- or 12-m radius using the skidding technique and a 12- or 15-m radius with step turning. Mechanical parameters were monitored using a real-time kinematic Global Navigation Satellite System and video analysis. Step turning was more effective during all phases of a turn, leading to higher velocities than skidding (P < .05). With both techniques, a greater radius was associated with higher velocity (P < .05), but the quality of turning, as assessed on the basis of energy characteristics, was the same. More effective skidding turns involved more pronounced deceleration early in the turn and maintenance of higher velocity thereafter, while more effective step turning involved lower energy dissipation during the latter half of the turn. In conclusion, the single-turn analysis employed here reveals differences in the various techniques chosen by elite cross-country skiers when executing downhill turns of varying radii and can be used to assess the quality of such turns. © 2014 Human Kinetics, Inc.
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43.
  • Solana-Tramunt, Mònica, et al. (författare)
  • Heart Rate Variability in Elite Synchronized Swimmers
  • 2019
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 14:4, s. 464-471
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To determine whether heart-rate variability (HRV) was correlated with other training-load and training-tolerance markers for monitoring the effect of a training session on elite synchronized swimmers.Methods: The authors recorded the resting HRV of 12 elite swimmers (mean age = 21.5 [3.5] y) 3 times over 1 wk with a cadence of 48 h prior to the 2015 World Swimming Championships. They continuously monitored heart rate and obtained salivary cortisol (SC) samples before and after the last training session of the week. The authors measured capillary blood lactate (La) 2, 4, and 8 min after the last training session and monitored recovery HRV. They assessed rating of perceived exertion (RPE) over the entire session and tested the association between the highest La concentration (Lapeak), SC, and RPE and relative changes (Δ%) in the natural logarithm of the root-mean-square successive difference of intervals (LnRMSSD). The authors also calculated the smallest worthwhile change of the averaged pre and post LnRMSSD measurements.Results: There were periods of pronounced bradycardia (60.5 [16.7] beats/ min) during training exercises corresponding to apneic exercise. The magnitude-based inferences showed nonclinically meaningful changes of LnRMSSD. Lapeak (6.8 [2.7] mmol/L) correlated positively with Δ%LnRMSSD and Δ%SC (r = .89, P = .001 and r = .61, P = .04, respectively). Conclusions: There was no change in LnRMSSD and Lapeak, Δ%SC, and RPE indicated reduced sympathetic activation and positive adaptation to the stress imposed by the session. Isolated HRV assessment may reveal a controversial interpretation of autonomic nervous system status or the training tolerance in elite synchronized swimming athletes due to the influence of the diving response.
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44.
  • Solli, Guro S., et al. (författare)
  • Changes in self-reported physical fitness, performance, and side effects across the phases of the menstrual cycle among competitive endurance athletes
  • 2020
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 15:9, s. 1324-1333
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To investigate changes in self-reported physical fitness, performance, and side effects across the menstrual cycle (MC) phases among competitive endurance athletes and to describe their knowledge and communication with coaches about the MC. Methods: The responses of 140 participants (older than 18 y) competing in biathlon or cross-country skiing at the (inter)national level were analyzed. Data were collected via an online questionnaire addressing participants' competitive level, training volume, MC history, physical fitness, and performance during the MC, MC-related side effects, and knowledge and communication with coaches about the MC and its effects on training and performance. Results: About 50% and 71% of participants reported improved and reduced fitness, respectively, during specific MC phases, while 42% and 49% reported improved and reduced performance, respectively. Most athletes reported their worst fitness (47%) and performance (30%) and the highest number of side effects during bleeding (P <.01; compared with all other phases). The phase following bleeding was considered the best phase for perceived fitness (24%, P <.01) and performance (18%, P <.01). Only 8% of participants reported having sufficient knowledge about the MC in relation to training, and 27% of participants communicated about it with their coach. Conclusions: A high proportion of athletes perceived distinct changes in fitness, performance, and side effects across the MC phases, with their worst perceived fitness and performance during the bleeding phase. Because most athletes indicate a lack of knowledge about the MC's effect on training and performance and few communicate with coaches on the topic, the authors recommend that more time be devoted to educating athletes and coaches. 
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45.
  • Sperlich, B., et al. (författare)
  • Does upper-body compression improve 3 × 3-min double-poling sprint performance?
  • 2014
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 9:1, s. 48-57
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To evaluate whether upper-body compression affects power output and selected metabolic, cardiorespiratory, hemodynamic, and perceptual responses during three 3-min sessions of double-poling (DP) sprint. Method: Ten well-trained male athletes (25 ± 4 y, 180 ± 4 cm, 74.6 ± 3.2 kg) performed such sprints on a DP ski ergometer with and without a long-sleeved compression garment. Result: Mean power output was not affected by such compression (216 ± 25 W in both cases; P = 1.00, effect size [ES] = 0.00), although blood lactate concentration was lowered (P < .05, ES = 0.50-1.02). Blood gases (ES = 0.07-0.50), oxygen uptake (ES = 0.04-0.28), production of carbon dioxide (ES = 0.01-0.46), heart rate (ES = 0.00-0.21), stroke volume (ES = 0.33-0.81), and cardiac output (ES = 0.20-0.91) were also all unaffected by upper-body compression (best P = 1.00). This was also the case for changes in the tissue saturation index (ES = 0.45-1.17) and total blood content of hemoglobin (ES = 0.09-0.85), as well as ratings of perceived exertion (ES = 0.15-0.88; best P = .96). Conclusion: The authors conclude that the performance of well-trained athletes during 3 × 3-min DP sprints will not be enhanced by upper-body compression. © 2014 Human Kinetics, Inc.
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46.
  • Sperlich, Billy, et al. (författare)
  • Salivary Cortisol, Heart Rate and Blood Lactate Responses During Elite Downhill Mountain Bike Racing
  • 2012
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 7:1, s. 47-52
  • Forskningsöversikt (refereegranskat)abstract
    • Purpose: This study aimed to quantify the intensity profile of elite downhill mountain bike races during competitions. Methods: Seventeen maledownhill racers (22 ± 5 y; 185.1 ± 5.3 cm; 68.0 ± 3.9 kg; VO 2peak: 59.4 ± 4.1 mL min kg -1) participated in the International German DownhillChampionships in 2010. The racers' peak oxygen uptake and heart rate (HR) at 2 and 4 mmol L -1 blood lactate (HR2 and HR 4), were assessed during an incremental laboratory step test (100 W, increase 40 W every 5 min). During the races, the HR was recorded and pre- and postrace bloodlactate concentrations as well as salivary cortisol levels were obtained. Results: During the race, the absolute time spent in the "easy" intensity zone was 23.3 ± 6.8 s, 24.2 ± 12.8 s (HR 2-HR 4) in the "moderate" zone, and 151.6 ± 18.3 s (>HR 4) in the "hard" zone. Eighty percent of the entire race was accomplished at intensities >90% HRpeak. Blood lactate concentrations postrace were higher than those obtained after the qualification heat (8.0 ± 2.5 mmol L -1 vs 6.7 ± 1.8 mmol L -1, P < .01). Salivary levels of cortisol before the competition and the qualification heat were twice as high as at resting state (P < .01). Conclusions: This study shows that mountain bike downhill races are conducted at high heart rates and levels of blood lactate as well as increased concentration of salivary cortisol as marker for psycho-physiological stress. © 2011 Human Kinetics, Inc.
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47.
  • Sperlich, Billy, et al. (författare)
  • Table tennis: Cardio-respiratory and metabolic analysis of match and exercise in elite junior national players
  • 2011
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 6:2, s. 234-242
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: The aim of the study was to determine the cardiorespiratory and metabolic characteristics during intense and moderate table tennis (TT) training, as well as during actual match play conditions. Methods: Blood lactate concentration (Lac), heart rate (HR, beats per minute [bpm]), oxygen uptake (VO(2)), and energy expenditure (EE) in 7 male participants of the German junior national team (age: 14 +/- 1 y, weight: 60.5 +/- 5.6 kg height; 165 +/- 8 cm) were examined during six training sessions (TS) and during an international match. The VO(2) was measured continuously with portable gas analyzers. Lac was assessed every 1 to 3 min during short breaks. Results: Mean (peak) values for Lac, HR, VO(2), and EE during the TS were 1.2 +/- 0.7 (4.5) mmol.L(-1), 135 +/- 18 (184) bpm, 23.5 +/- 7.3 (43.0) mL.kg(-1).min-(1), and 6.8 +/- 2.0 (11.2) METs, respectively. During match play, mean (peak) values were 1.1 +/- 0.2 (1.6) mmol.L(-1), 126 +/- 22 (189) bpm, 25.6 +/- 10.1 (45.9) mL.kg(-1).min(-1), and 4.8 +/- 1.4 (9.6) METs, respectively. Conclusions: For the first time, cardiorespiratory and metabolic data in elite junior table tennis have been documented demonstrating low cardiorespiratory and metabolic demands during TT training and match play in internationally competing juniors.
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48.
  • Staunton, Craig A., et al. (författare)
  • A Framework for the Standardization of Game Analysis in Ice Hockey
  • 2023
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 18:5, s. 458-464
  • Tidskriftsartikel (refereegranskat)abstract
    • Background:Compared with other major global team sports such as football or basketball, ice hockey has received considerably less attention in sport-science research. However, the research focus on ice hockey performance is growing rapidly. Unfortunately, despite the growing interest in ice hockey, among the little research that has been conducted there are inconsistencies in terminology and methodology in the study of physiology and performance during games. The need for systematic and standardized reporting of study methodology is vital, as a lack of methodological detail or methodological inconsistencies make it impossible to replicate published studies, and alterations in the methodologies used can influence the measured demands imposed on players. Accordingly, this prohibits the ability of coaches to generate game-replicating training programs, decreasing the application of research findings to practice. In addition, a lack of methodological detail or methodological inconsistencies can result in incorrect conclusions being made from research.Purpose:In this invited commentary, we aim to increase awareness regarding the current standard of methodological reporting in ice hockey game-analysis research. In addition, we have developed a framework for the standardization of game analysis in ice hockey in order to allow for greater replication in future research and to increase the application of published findings to practice.Conclusions:We implore researchers in the field to consult the Ice Hockey Game Analysis Research Methodological Reporting Checklist in order to adopt a detailed reporting standard of methodologies in future work to help improve the applicability of research outcomes.
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49.
  • Staunton, Craig A., et al. (författare)
  • Heart Rate Does Not Accurately Predict Metabolic Intensity During Variable-Intensity Roller Skiing or Cycling
  • 2022
  • Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 17:12, s. 1664-1671
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose:To critically appraise the utility of heart rate (HR) and power output (PO) to predict metabolic rate (MR) and oxygen consumption ( ˙VO2 ) during variable-intensity roller skiing and cycling.Methods:National-level cyclists (n = 8) and cross-country skiers (n = 9) completed a preliminary session to determine ˙VO2max , and a variable-intensity protocol with 3 high-intensity stages at 90% ˙VO2max for 3 minutes interspersed with 3 moderate-intensity stages at 70% ˙VO2max for 6 minutes. Cardiorespiratory measures were recorded throughout. Linear HR–MR, HR–˙VO2 , PO–MR, and PO–˙VO2 regressions were computed from the preliminary session, individually, for all athletes and used to predict MR and ˙VO2 from both HR and PO, separately, during the variable-intensity protocol. Mean differences with 95% limits of agreement (LOA) between measured and predicted MR and ˙VO2 were calculated.Results:MR and ˙VO2 estimated from HR displayed a mean bias close to zero but wide LOA. HR overestimated MR and ˙VO2 during moderate intensity but underestimated MR and ˙VO2 during high intensity, for both roller skiing and cycling. MR and ˙VO2 estimated from PO were more consistent across the experimental trial, displaying a mean bias farther from zero but with tighter LOA.Conclusions:This study has demonstrated that HR has limited utility to predict metabolic intensity during variable-intensity roller skiing and cycling because of wide LOA. On the other hand, metabolic intensity predicted from PO had tighter LOA, suggesting better consistency. PO might provide a better prediction of metabolic intensity compared with HR, particularly when longer-duration steps are performed during preliminary testing.
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50.
  • Staunton, Craig A., et al. (författare)
  • Heart Rate–Blood Lactate Profiling in World-Class Biathletes During Cross-Country Skiing : The Difference Between Laboratory and Field Tests
  • 2023
  • Ingår i: International Journal of Sports Physiology and Performance. - 1555-0265 .- 1555-0273. ; 18:7, s. 780-785
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To identify differences in heart rate (HR) and concentration of blood lactate ([La]) relationships between laboratory and field-based skate-roller-skiing tests.Methods: Fourteen world-class biathletes (8 women, 6 men) completed a laboratory- and field-based roller-skiing test using the skate technique. The laboratory-based test comprised 5 to 7 submaximal steps at a fixed incline and speed on a roller-skiing treadmill. The field-based test comprised 5 steps on a course where the final hill was designed to mimic the conditions of the laboratory test. HR and [La] were measured for each step. The HR associated with 2 mmol·L−1(HR@2 mmol) and 4 mmol·L−1 (HR@4 mmol) of [La] was calculated using an interpolation method. A 1-way analysis of variance and Bland–Altman analyses with 95% limits of agreement (LoA) were used to determine if test type influenced HR@2 mmol orHR@4 mmol. A second-order polynomial was fitted to group-level data to highlight the HR–[La] relationships for laboratory- and field-based tests.Results: HR@2 mmol was lower for field tests than for laboratory tests (mean bias: 1.9%HRmax; 95% LoA: −4.5 to+8.3%HRmax; P < .001). HR@4 mmol was also lower for field tests compared to laboratory tests (mean bias: 2.4%HRmax; 95%LoA: −1.2 to +6.0%HRmax; P < .001). On the group level, the lactate threshold occurred at a lower HR during roller skiing in the field compared to the laboratory.Conclusions: The findings from this study confirm that for a given HR, [La] was greater in field compared with laboratory-based conditions. These results might have implications for how coaches define training-intensity“zones” during skate roller skiing based on laboratory tests.
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