| 1. |
- 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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| 2. |
- 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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| 3. |
- Karlsson, Øyvind, 1989-, et al.
(författare)
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Training and illness characteristics of crosscountry skiers transitioning from junior to senior level
- 2021
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:5 May
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Tidskriftsartikel (refereegranskat)abstract
- Objective This study aimed to describe the endurance training and incidence of illnesses reported by a group of well-trained cross-country (XC) skiers throughout their transition from junior to senior level. Methods Changes in self-reported training and performance, from 31 well-trained XC skiers, were analyzed from the start of the season they turned 16 y until the end of the season they turned 22 y, using linear mixed-effects models. Differences in the incidence of self-reported illness episodes were analyzed using incidence rate ratios, and the relationships between selfreported illness and training volumes were analyzed using linear mixed-effects models in a sub-group of 23 of the skiers. Results In total, 145 seasons of training data (including 85,846 h of endurance training) and 109 person- years of illness data (including 380 self-reported illness episodes) were analyzed. The athletes progressively increased their annual endurance training volume from age 16 to 22 y in a linear fashion, from ~ 470 to 730 h. Low- and high-intensity training volumes increased by 51.4 ± 2.4 h·y-1 (p < .001) and 4.9 ± 0.6 h·y-1 (p < .001), respectively. Sport-specific and non-specific training increased by 50.0 ± 2.2 h·y-1 (p < .001) and 4.6 ± 2.0 h·y-1 (p < .001), respectively. The athletes reported a median (range) of 3 (0-8) illness episodes and 17 (0- 80) days of illness per year, and there was an inverse relationship between self-reported illness days and annual training volume (-0.046 ± 0.013 d?h-1; p < .001). Conclusions This group of well-trained XC skiers increased their endurance training volume in a linear fashion by ~ 55 h annually. This was primarily achieved through an increase in low-intensity and sport-specific training. Furthermore, higher training volumes were associated with a lower number of self-reported illness days.
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| 4. |
- Köykkä, Miika, et al.
(författare)
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Rifle and aiming point accelerations do not differ between the most and least accurate shots in biathlon shooting within an athlete
- 2023
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Ingår i: Biomedical Human Kinetics. - : Walter de Gruyter GmbH. - 2080-2234. ; 15:1, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Study aim: As studies from shooting disciplines other than biathlon have observed associations between weapon accelerations and shooting performance, this study investigated whether accelerations of the rifle stock and aiming point (the point on the target where the rifle is aimed at) are associated with shooting performance, and differences in rifle and aiming point accelerations between the most and least accurate shots. Further, associations between rifle and aiming point accelerations were studied.Materials and methods: Shooting performance (Hit(Dist), hit point distance from the center of the target) along with rifle and aiming point accelerations were measured from nine biathletes who performed 6x5 biathlon prone and standing shots.Results: In the prone posture, rifle or aiming point accelerations were neither associated with shooting performance nor with each other. In the standing posture, vertical rifle accelerations right before triggering were negatively associated with Hit(Dist) (r = -0.70, p < 0.05), whereas aiming point accelerations were not associated with Hit(Dist). Horizontal rifle accelerations were positively associated with aiming point accelerations in standing (r = 0.74, p = 0.024), whereas vertical or resultant rifle accelerations did not demonstrate associations with aiming point accelerations. In both postures, rifle accelerations were of the same magnitude in the most and least accurate shots.Conclusion: Rifle and aiming point accelerations provide limited description of the technical level in biathlon shooting. Moreover, rifle accelerations alone do not appear to provide sufficient information to deduce the aiming point movements. Angular movement would likely be required for aiming point movement estimation.
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| 5. |
- Laaksonen, Marko S, 1975-, et al.
(författare)
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VO2peak, myocardial hypertrophy, and myocardial blood flow in endurance-trained men
- 2014
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Ingår i: Medicine and science in sports and exercise. - 1530-0315. ; 46:8, s. 1498-1505
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Endurance training induces cardiovascular and metabolic adaptations, leading to enhanced endurance capacity and exercise performance. Previous human studies have shown contradictory results in functional myocardial vascular adaptations to exercise training, and we hypothesized that this may be related to different degrees of hypertrophy in the trained heart. METHODS: We studied the interrelationships between peak aerobic power (V̇O2peak), myocardial blood flow (MBF) at rest and during adenosine-induced vasodilation, and parameters of myocardial hypertrophy in endurance-trained (ET, n = 31) and untrained (n = 17) subjects. MBF and myocardial hypertrophy were studied using positron emission tomography and echocardiography, respectively. RESULTS: Both V̇O2peak (P < 0.001) and left ventricular (LV) mass index (P < 0.001) were higher in the ET group. Basal MBF was similar between the groups. MBF during adenosine was significantly lower in the ET group (2.88 ± 1.01 vs 3.64 ± 1.11 mLg-1min-1, P < 0.05) but not when the difference in LV mass was taken into account. V̇O2peak correlated negatively with adenosine-stimulated MBF, but when LV mass was taken into account as a partial correlate, this correlation disappeared. CONCLUSIONS: The present results show that increased LV mass in ET subjects explains the reduced hyperemic myocardial perfusion in this subject population and suggests that excessive LV hypertrophy has negative effect on cardiac blood flow capacity.
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| 6. |
- Lögdal, Nestor, et al.
(författare)
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Individual Fluctuations in Blood Lactate Concentration During an Ice Hockey Game; Differences Between Player Positions
- 2022
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Ingår i: International Journal of Exercise Science. - : Western Kentucky University. - 1939-795X. ; 15:6, s. 985-993
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Tidskriftsartikel (refereegranskat)abstract
- International Journal of Exercise Science 15(6): 985-993, 2022. The main purpose of the current study was to provide an in-depth description of individual player’s intra-game physiological responses during an ice hockey game. A secondary aim was to compare these responses between forwards and defensemen. Six elite junior ice hockey players, three forwards and three defensemen, median (interquartile range) 17 (17–17) years, 182 (180– 185) cm, and 78 (74– 80) kg were recruited to participate in the study. Capillary blood samples were taken following each shift and analyzed for blood lactate concentration (BLC). Heart rate (HR) was registered continuously throughout the game. The game was filmed and shift lengths were determined retrospectively using a time-motion analysis. All players had BLC ranging between 1.8 and 10.7 mmol/L (mean = 5.5 mmol/L), with forwards reaching a significantly higher value than defensive players (F1,32 = 75.2, p < 0.0001), a significant effect of time was also observed (F2,25 = 6.4, p = 0.0058). During the game, the players accumulated 11:18 ± 5:04 (minutes:seconds) above 90% of their maximal heart rate (HRmax), but the majority of the time was below 80% of HRmax. The fluctuations in BLC and heart rate demonstrate that the intensity is highly variable during games and challenges both aerobic and anaerobic metabolic pathways. The higher BLC of forwards might indicate that they perform more high-intensity work during games than defensive players.
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| 7. |
- Staunton, Craig A., et al.
(författare)
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Performance and Micro‑Pacing Strategies in Biathlon Skiing
- 2023
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Ingår i: Journal of Science in Sport and Exercise. - : Springer Nature. - 2096-6709 .- 2662-1371.
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To examine the micro-pacing (within-lap) strategies during biathlon skiing with and without the biathlon rifle. Methods Twenty biathletes (7 women, 13 men) performed two crosscountry skiing time-trials on a ≈2300 m course, once with and once without the biathlon rifle. During time-trials, biathletes wore a sensor that recorded position, distance and skiing-speed. A trajectory correction and statistical parametric mapping procedure determined the course positions (clusters) where instantaneous skiing-speed was significantly related to time-trial performance. The time differences between the fastest and slowest skier in these clusters were calculated. Results The fastest biathletes skied with greater instantaneous speeds in specific clusters, which included both uphill and downhill sections. The clusters represented time gains for the fastest skier over the slowest skier of between 16.1 and 25.8 s for the women and between 18.9 and 21.9 s for the men. The largest time gains between the fastest and slowest biathletes were observed in a downhill section that was preceded by a 180° turn, where time gains were between 2.9 and 4.1 s in clusters of between just 12 to 62 m. In biathlon skiing with-rifle, there were more clusters that were not present during without-rifle. When skiing with-rifle, there were additional clusters in the uphill sections that represented time gains of 5.2 s and 2.3 s for the women and men, respectively. Conclusions Statistical parametric mapping can be used in biathlon to provide pacing and performance feedback to athletes and coaches.
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| 8. |
- Toolis, Thomas, et al.
(författare)
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Effects of Neurofeedback Training on Frontal Midline Theta Power, Shooting Performance, and Attentional Focus With Experienced Biathletes
- 2023
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Ingår i: Journal of Clinical Sport Psychology. - : Human Kinetics. - 1932-9261 .- 1932-927X.
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Tidskriftsartikel (refereegranskat)abstract
- Frontal midline theta power (FMT) has been associated with superior rifle shooting performance. Our experiment examined whether electroencephalographic-based training could increase FMT, shooting performance, and attentional focus in highly trained/elite biathletes. Participants (n = 28; age, M = 21.7, SD = 2.3) were assigned to a control group or an intervention group (with 3 hr of neurofeedback training). FMT increased from baseline during the neurofeedback training sessions (p <= .05). However, there were no Group x Pre-post training (test) interactions for FMT or shooting performance (p > .05). There was a small Group x Test effect for attentional focus (p = .07, eta 2p = .12), indicating a potential benefit of neurofeedback training. Superior shooters were more proficient at increasing FMT during neurofeedback training, but this did not translate to greater improvements in shooting performance. Our findings suggest that the effects of neurofeedback training are transient and do not necessarily benefit performance.
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