| 1. |
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| 2. |
- Andersson, Erik P., 1984-, et al.
(författare)
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Anaerobic work capacity in cycling : the effect of computational method
- 2022
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 122, s. 2637-2650
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To compare the anaerobic work capacity (AnWC, i.e., attributable anaerobic mechanical work) assessed using four different approaches/models applied to time-trial (TT) cycle-ergometry exercise. Methods Fifteen male cyclists completed a 7 x 4-min submaximal protocol and a 3-min all-out TT (TTAO). Linear relationships between power output (PO) and submaximal metabolic rate were constructed to estimate TT-specific gross efficiency (GE) and AnWC, using either a measured resting metabolic rate as a Y-intercept (7 + Y-LIN) or no measured Y-intercept (7-Y-LIN). In addition, GE of the last submaximal bout (GE(LAST)) was used to estimate AnWC, and critical power (CP) from TTAO (CP3'AO) was used to estimate mechanical work above CP (W', i.e., "AnWC"). Results Average PO during TTAO was 5.43 +/- 0.30 and CP was 4.48 +/- 0.23 W.kg(-1). The TT-associated GE values were similar to 22.0% for both 7 + Y-LIN and 7-Y-LIN and similar to 21.1% for GE(LAST) (both P < 0.001). The AnWC were 269 +/- 60, 272 +/- 55, 299 +/- 61, and 196 +/- 52 J.kg(-1) for the 7 + Y-LIN, 7 Y-LIN, GE(LAST), and CP3'AO models, respectively (7 + Y-LIN and 7-Y-LIN versus GE(LAST), both P <0.001; 7+ Y-LIN, 7 Y-LIN, and GE(LAST) versus CP3'AO, all P < 0.01). For the three pair-wise comparisons between 7+ Y-LIN, 7-Y-LIN, and GE(LAST), typical errors in AnWC values ranged from 7 to 11 J.kg(-1), whereas 7+ Y-LIN, 7-Y-LIN, and GE(LAST) versus CP3'AO revealed typical errors of 55-59 J.kg(-1). Conclusion These findings demonstrate a substantial disagreement in AnWC between CP3'AO and the other models. The 7 + Y-LIN and 7-Y-LIN generated 10% lower AnWC values than the GE(LAST) model, whereas 7 + Y-LIN and 7-Y-LIN generated similar values of AnWC.
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| 3. |
- Andersson, Erik P., 1984-, et al.
(författare)
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The effect of exercise hyperpnea on gross efficiency and anaerobic capacity estimates during a 3-min cycle time trial
- 2023
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Ingår i: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 134:2, s. 253-263
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to analyze the effect of exercise-induced hyperpnea on gross efficiency (GE) and anaerobic capacity estimates during a self-paced 3-min supramaximal cycle time trial (TT). Fourteen highly trained male cyclists performed 7 × 4-min submaximal stages, a 6-min passive rest, a 3-min TT, a 5-min passive rest, and a 6-min submaximal stage. Three models were based on the 7 × 4-min linear regression extrapolation method, using 1) the conventional model (7-YLIN); 2) the same 7-YLIN model but correcting for the additional ventilatory cost (i.e., hyperpnea) (7-YLIN-V-cor); and 3) accounting for linearly declining GE during the TT (7-YLIN-D). The other three models were based on GE from the last submaximal stage, using the conventional model (GELAST) and the same modifications as described for 7+YLIN, i.e., 1) GELAST, 2) GELAST-V-cor, and 3) GELAST-D. The GELAST model generated 18% higher values of anaerobic capacity than the 7-YLIN model (P < 0.05). During the TT, the hyperpnea-corrected model (i.e., 7-YLIN-V-cor or GELAST-V-cor) generated, compared with the respective conventional model (i.e., 7-YLIN or GELAST), ∼0.7 percentage points lower GE and ∼11% higher anaerobic capacity (all, P < 0.05). The post-TT GE was 1.9 percentage points lower (P < 0.001) and the 7-YLIN-D or GELAST-D model generated, compared with the respective conventional model, a lower GE (∼1.0 percentage points) and ∼17% higher anaerobic capacity during the TT (all, P < 0.05). In conclusion, the correction for a declining GE due to hyperpnea during a supramaximal TT resulted in an increased required total metabolic rate and anaerobic energy expenditure compared with the conventional models.NEW & NOTEWORTHY This study demonstrates that GE declines during a 3-min supramaximal cycle TT, which is possibly related to the hyperpneic response during supramaximal exercise. The finding from this study also provides novel insight into how the increased ventilatory energy cost from exercise-induced hyperpnea contributes to decreased GE, increased required total metabolic rate, and increased anaerobic energy expenditure during supramaximal exercise. Therefore, conventional linear models for estimating anaerobic capacity are likely to generate underestimated values.
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| 4. |
- Born, Dennis-Peter, et al.
(författare)
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Predicting future stars : Probability and performance corridors for elite swimmers
- 2024
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Ingår i: Journal of Science and Medicine in Sport. - : Elsevier BV. - 1440-2440 .- 1878-1861. ; 27:2, s. 113-118
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo evaluate the new age groups of the World Junior Championships in swimming from a scientific perspective, establish benchmarks and performance corridors that predict success at peak performance age and compare performance corridors between men and women and short-, middle-, and long-distance freestyle races.DesignLongitudinal big data analysis.MethodsIn total, 347,186 annual best times of male (n = 3360, 561 ± 177 Swimming Points) and female freestyle swimmers (n = 2570, 553 ± 183 Swimming Points) were collected across all race distances at peak performance age and retrospectively analyzed throughout adolescence. Cumulative Poisson distribution was used to calculate probabilities of becoming world-class finalist, international-class, or national-class swimmer for each age group. Performance corridors were expressed relative to the World Record and compared between performance levels, sex, race distances, and age groups with a 2-way analysis of variance.ResultsFemales are required to swim faster relative to the World Record at a younger age and show earlier performance plateaus than males at national and international levels. Additionally, world-class long-distance finalists show higher Swimming Points earlier in their career compared to short-distance swimmers. This effect is more distinctive in females than males.ConclusionsBased on the sex-specific performance corridors and developments, the newly aligned age groups for the World Junior Championships are questionable regarding long-term athlete development. Based on race times from 131 nations, the present benchmarks provide valid international normative values to predict success chances at peak performance age and guide young swimmers along their talent pathway.AbbreviationsFINA, Fédération Internationale de Natation; 850 swimmers, world-class finalists; 750 swimmers, international-class swimmers; 650 swimmers, national-class swimmers
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| 5. |
- Born, Dennis-Peter, et al.
(författare)
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Specialize Early and Select Late : Performance Trajectories of World-Class Finalists and International- and National-Class Swimmers
- 2024
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Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 19:2, s. 164-172
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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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| 6. |
- Born, Dennis-Peter, et al.
(författare)
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Variation vs. specialization : the dose-time-effect of technical and physiological variety in the development of elite swimmers
- 2024
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Ingår i: BMC Research Notes. - : Springer Nature. - 1756-0500. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveIt is heavily discussed whether larger variety or specialization benefit elite performance at peak age. Therefore, this study aimed to determine technical (number of different swimming strokes) and physiological (number of different race distances) variety required to become an international-class swimmer (> 750 swimming points) based on 1′522′803 race results.ResultsCorrelation analyses showed lower technical variety in higher ranked swimmers (P < 0.001), yet with small effects (0.11–0.30). However, Poisson distribution revealed dose-time-effects and specified number of swimming strokes required during each age group. Specifically, freestyle swimmers showed highest chances when starting to compete in three to four swimming strokes but reduced their variety to three swimming strokes at the ages of 12/13yrs with another transition to two swimming strokes at the ages of 19/21yrs (female/male swimmers, respectively). Although both sexes showed similar specialization pattern throughout their career, earlier specialization was generally evident in female compared to male swimmers. At peak performance age, freestyle was most frequently combined with butterfly. Swimmers who either kept competing in all five swimming strokes or focused on only one at the beginning of their careers showed lowest probability of becoming an international-class swimmer. Physiological variety increased during junior age but declined again to three race distances towards elite age.
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| 7. |
- Jonsson Kårström, Malin, et al.
(författare)
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Kinematical Effects of Rifle Carriage on Roller-Skiing in Well-Trained Female and Male Biathletes
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Purpose This study aimed to investigate how rifle carriage and skiing speed during biathlon roller-skiing affect range of motion (ROM) in joint angles and equipment (skis and poles), the vertical distance between shoulders and treadmill (vertdist), as well as possible sex differences associated with rifle carriage. Methods Fourteen biathletes (6 women, 8 men) roller-skied on a treadmill at submaximal and simulated race speeds, with (WR) and without (NR) a rifle, using gears 3 and 2. Kinematical data for the whole body, poles, roller-skis, rifle and treadmill were monitored using a 3D motion capture system. Movements determined as flexion/extension (x), abduction/adduction (y) and/or internal/external rotation (z) were analyzed for the hip, shoulder, thorax, knee, ankle, elbow, poles and roller-skis. ROM (the difference between maximal and minimal angles) in joints and equipment, and vertdist were analyzed over six skiing cycles during each condition (WR and NR) and speed. Results The maximal vertdist was lower for WR compared to NR (gear 3: 1.53±0.06 vs 1.54±0.06 m; gear 2: 1.49±0.06 vs 1.51±0.06 m; both p<0.001). ROM in the upper body was altered when roller-skiing WR (movements decreased in thorax and shoulder (x) and increased in elbow (only gear 3) (x), thorax (only gear 2) and shoulder (y) and (z); all p><0.05) and increased with speed, without differences between sexes (p>0.05). Conclusion Since rifle carriage and speed appear to affect the kinematics of rollerskiing, coaches and biathletes are advised to perform skiing technique training under competition-like conditions (i.e., at race speeds while carrying the rifle).
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| 8. |
- Jonsson Kårström, Malin, et al.
(författare)
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Kinematical effects of rifle carriage on roller skiing in well-trained female and male biathletes
- 2023
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 33:4, s. 444-454
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study aimed to investigate how rifle carriage and skiing speed during biathlon roller skiing affect range of motion (ROM) in joint angles and equipment (skis and poles), the vertical distance between shoulders and treadmill (vertdist), as well as possible sex differences associated with rifle carriage. Methods: Fourteen biathletes (6 women, 8 men) roller-skied on a treadmill at submaximal and simulated race speeds, with (WR) and without (NR) a rifle, using gears 3 and 2. Kinematical data for the whole body, poles, roller-skis, rifle, and treadmill were monitored using a 3D motion capture system. Movements determined as flexion/extension (x), abduction/adduction (y), and/or internal/external rotation (z) were analyzed for the hip, shoulder, thorax, knee, ankle, elbow, poles, and roller skis. ROM (the difference between maximal and minimal angles) in joints and equipment, and vertdist were analyzed over six skiing cycles during each condition (WR and NR) and speed. Results: The maximal vertdist was lower for WR compared with NR (gear 3: 1.53 ± 0.06 vs 1.54 ± 0.06 m; gear 2: 1.49 ± 0.06 vs 1.51 ± 0.06 m; both p < 0.001). ROM in the upper body was altered when roller skiing WR (movements decreased in thorax and shoulder (x) and increased in elbow (only gear 3) (x), thorax (only gear 2), and shoulder (y) and (z); all p < 0.05) and increased with speed, without differences between sexes (p > 0.05). Conclusion: Since rifle carriage and speed appear to affect the kinematics of roller skiing, coaches, and biathletes are advised to perform skiing technique training under competition-like conditions (i.e., at race speeds while carrying the rifle).
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| 9. |
- Staunton, Craig A., et al.
(författare)
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The Relationship Between Cardiorespiratory and Accelerometer-Derived Measures in Trail Running and the Influence of Sensor Location
- 2022
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Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 17:3, s. 474-483
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To examine the relationship between cardiorespiratory and accelerometer-derived measures of exercise during trailrunning and determine the influence of accelerometer location.Methods: Eight trail runners (7 males and 1 female; age 26 [5] y;maximal oxygen consumption [ ̇VO2] 70 [6] mL·kg−1·min−1) completed a 7-km trail run (elevation gain: 486 m), with concurrentmeasurements of ̇VO2, heart rate, and accelerations recorded from 3 triaxial accelerometers attached at the upper spine, lowerspine, and pelvis. External exercise intensity was quantified from the accelerometers using PlayerLoad™ per minute andaccelerometry-derived average net force. External exercise volume was calculated using accumulated PlayerLoad and the product of average net force and duration (impulse). Internal intensity was calculated using heart rate and ̇VO2-metrics; internal volume was calculated from total energy expenditure (work). All metrics were analyzed during both uphill (UH) and downhill(DH) sections of the trail run.Results: PlayerLoad and average net force were greater during DH compared with UH for all sensorlocations (P ≤ .004). For all accelerometer metrics, there was a sensor position × gradient interaction (F2,1429.003;P <.001). The upper spine was lower compared with both pelvis (P ≤ .003) and lower spine (P ≤ .002) for all accelerometermetrics during both UH and DH running. Relationships between accelerometer and cardiorespiratory measures during UH running ranged from moderate negative to moderate positive (r = −.31 to .41). Relationships were stronger during DH running where there was a nearly perfect correlation between work and impulse (r = .91; P < .001).Conclusions: Simultaneous monitoring of cardiorespiratory and accelerometer-derived measures during trail running is suggested because of the disparity between internal and external intensities during changes in gradient. Sensor positioning close to the center of mass isrecommended.
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| 10. |
- Stöggl, Thomas, et al.
(författare)
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A Systematic Review of the Effects of Strength and Power Training on Performance in Cross-Country Skiers
- 2022
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Ingår i: Journal of Sports Science and Medicine (JSSM). - : Department of Sports Medicine, Uludag University. - 1303-2968. ; 21:4, s. 555-579
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Forskningsöversikt (refereegranskat)abstract
- To identify and evaluate current scientific literature concerning the effect of strength, power and speed training on relevant phys-iological and biomechanical characteristics and performance of competitive cross-country skiers (XCS), the databases Scopus and PubMed were searched systematically for original articles in peer-reviewed journals. Of the 599 studies retrieved, 12 met the inclusion criteria (i.e., assessment of outcome measures with rel-evance for XCS performance; involvement of traditional re-sistance training; application of external resistance to the body; intervention longer than 4 weeks; randomized controlled trial). The methodological rigor of each study was assessed using the PEDro scale, which were mostly poor-to-fair, with good method-ological quality in only two articles. All of the strength/power/speed interventions improved 1RM (0.8 -6.8 ES), but findings with respect to jump performance, ability to generate force rapidly and body composition were mixed. Interventions demonstrated moderate-to-high ES on XCS specific performance compared with control (mean ES = 0.56), but the pattern observed was not consistent. None of the interventions changed anaerobic capacity, while in most studies VO2max was either unchanged or increased. Work economy or efficiency was enhanced by most of the interventions. In conclusion, present research indicates that strength training improves general strength, with moderate effects on XCS performance, and inconclusive effects on work economy and VO2max/VO2peak. Strength training with high loads, explosive strength training, or sprint interval training seem to be promising tools for modern XCS training. Future investigations should in-clude long-term (e.g., >6 months) strength training to allow suf-ficient time for increased strength and speed to influence actual XCS performance. Moreover, they should include both sexes, as well as upper-and lower-body muscles (trained separately and together) and employ free weights and core training. Methodo-logical differences and limitations highlighted here may explain discrepancies in findings and should be taken into consideration in future research in this area.
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| 11. |
- Takeda, Masaki, et al.
(författare)
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Skating technique detection in cross-country skiing using a kinematic global navigation satellite system. The difference between fast and slow gliding skies
- 2022
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Ingår i: Abstract Book of the 9th Congress on Science and Skiing. - Salzburg, Austria : University of Salzburg, Austria.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: Technique detection in both classical and skating in cross-country skiing is an essential issue to improve competitive performance [1]. In this study, we tried to detect skating sub-techniques, V1, V2, V2a, and others (turning or gliding) using a kinematic global navigation satellite system (GNSS). METHODS: Participants were one male skier aged 41 yrs, former Olympic athlete, and two females (aged 41 yrs and 24 yrs, former XC competitive skiers) in Japan. Each participant performed 2-time trials of 3 km with the skating technique with 1-hour rest in between trials. One time trial with a slower gliding speed ski and 1 with faster gliding ski controlled by different kinds of ski waxing and in randomized order across participants. Air temperature was -1 ℃. A triple-band helical GNSS antenna was attached on the top of the skier’s head and the kinematic positioning data was measured by a data logger, with a sampling rate 10 Hz (The measurement accuracy 1 to 2 cm [2]). A video camera (GoPro Hero 9 Black) was attached on the chest of the participant to focus on skiing movement to detect the used technique during skiing. Both vertical and lateral head movements were visually extracted from the GNSS position data to determine the characteristics of each sub-technique. The number of each sub-technique counted by GNSS were compared with video-counted data in both faster and slower gliding skis respectively. RESULTS: The match ratio of the used all-technique counts between video and GNSS data for a total of six trials was 99.5±0.4%. Match ratios of V1 (101.2±1.5%), V2 (98.5±4.0%), V2a (109.4 ±16.7%), and others (94.9 ±19.0%) were observed. When participants used a faster gliding ski, the used technique ratio for V1 was almost unaltered, V2 decreased (-41 to -5%), V2a increased (6 to 21%), and others increased (-10 to 59%) compared to slower gliding ski. DISCUSSION/CONCLUSION: Both vertical and lateral head movement analysis using GNSS position data can detect all sub-techniques in skating. Changing ski gliding speed resulted in altered the use of the skating sub-technique ratio.
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