Search Results

The aim of this study was to compare the kinematics in throwing with a regular weighted handball with 20% lighter and heavier balls in female experienced handball players. In total, eight joint movements during the throw were analyzed. The analysis consisted of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timings during the throw. Results on 24 experienced female team handball players (mean age 18.2 ± 2.1 years) showed that the difference in ball weight affected the maximal ball velocity. The difference in ball release velocity was probably a result of the significant differences in kinematics of the major contributors to overarm throwing: elbow extension and internal rotation of the shoulder. These were altered when changing the ball weight, which resulted in differences in ball release velocity.

Changes in pedaling rate during cycling have been found to alter the pedal forces. Especially, the force effectiveness is reduced when pedaling rate is elevated. However, previous findings related to the muscular force component indicate strong preferences for certain force directions. Furthermore, inertial forces (due to limb inertia) generated at the pedal increase with elevated pedaling rate. It is not known how pedaling rate alters the inertia component and subsequently force effectiveness. With this in mind, we studied the effect of pedal rate on the direction of the muscle component, quantified with force effectiveness. Cycle kinetics were recorded for ten male competitive cyclists at five cadences (60–100 rpm) during unloaded cycling (to measure inertia) and at a submaximal load (~260 W). The force effectiveness decreased as a response to increased pedaling rate, but subtracting inertia eliminated this effect. This indicates consistent direction of the muscle component of the foot force.

The aim of this study was to investigate the contribution of upper extremity, trunk, and lower extremity movements in overarm throwing in team handball. In total, 11 joint movements during the throw were analyzed. The analysis consists of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timing during the throw. Only the elbow angle (extension movement range) and the level of internal rotation velocity of the shoulder at ball release showed a significant relationship with the throwing performance. Also, a significant correlation was found for the timing of the maximal pelvis angle with ball velocity, indicating that better throwers started to rotate their pelvis forward earlier during the throw. No other significant correlations were found, indicating that the role of the trunk and lower limb are of minor importance for team handball players.

Purpose: To provide novel insight regarding the influence of exercise modality on training load management by (1) providing a theoretical framework for the impact of physiological and biomechanical mechanisms associated with different exercise modalities on training load management in endurance exercise and (2) comparing effort-matched low-intensity training sessions performed by top-level athletes in endurance sports with similar energy demands. Practical Applications and Conclusions: The ability to perform endurance training with manageable muscular loads and low injury risks in different exercise modalities is influenced both by mechanical factors and by muscular state and coordination, which interrelate in optimizing power production while reducing friction and/or drag. Consequently, the choice of exercise modality in endurance training influences effort beyond commonly used external and internal load measurements and should be considered alongside duration, frequency, and intensity when managing training load. By comparing effort-matched low- to moderate-intensity sessions performed by top-level athletes in endurance sports, this study exemplifies how endurance exercise with varying modalities leads to different tolerable volumes. For example, the weight-bearing exercise and high-impact forces in long-distance running put high loads on muscles and tendons, leading to relatively low training volume tolerance. In speed skating, the flexed knee and hip position required for effective speed skating leads to occlusion of thighs and low volume tolerance. In contrast, the non-weight-bearing, low-contraction exercises in cycling or swimming allow for large volumes in the specific exercise modalities. Overall, these differences have major implications on training load management in sports.

Biathlon is an Olympic winter sport that combines rifle shooting and cross-country skiing in various race formats. In the individual distance (15 km for women and 20 km for men), athletes compete over 5 laps of skiing with shooting between each 2 laps (ie, 4 shootings). The aim of the current study was to compare total race time differences, as well as the contribution from cross-country skiing and shooting variables to this difference, between biathletes of different performance levels and sexes in individual races in the Biathlon World Cup. Based on the publicly available race reports, the authors compared these factors between top-10 results (G1–10) and results within rank 21–30 (G21–30), as well as the corresponding sex differences. G21–30 among men/women were on average 4%/6% behind G1–10 in total race time, in which course time accounted for 42%/54% of the overall performance difference, followed by 53%/44% explained by penalty time caused by shooting performance (ie, the number of hits). The remaining 2–3% was explained by differences in shooting time and range time. Women G1–10 were on average 15% slower in skiing speed than men G1–10, which accounted for 92% of the overall performance difference between sexes. In total, among G1–10, men shot on average 15 s faster than women, and total penalty time was 18 s shorter. In conclusion, course time and penalty time contributed approximately equally to the performance-level differences, whereas course time explained above 90% of the sex differences in individual World Cup biathlon races.

Biathlon is an Olympic sport combining cross-country skiing with the skating technique and rifle shooting. The sprint (7.5 km for women and 10 km for men) includes 2 shootings between 3 laps of skiing. The aims of the current study were to compare biathletes of different performance levels and sex on total race time and performance-determining factors of sprint races in the biathlon World Cup. The top-10 performers (G1-10) and results in ranks 21–30 (G21-30) in 47 sprint races during the 2011–12 to 2015–16 World Cup seasons were compared regarding total race time, course time, shooting time, range time, shooting performance (rate of hits), and penalty time. G21-30 men and women were on average 3–5% behind G1-10 in total race time, in which course time accounted for 59–65% of the overall performance difference, followed by 31–35% explained by penalty time. The remainder (ie, 4–6%) was explained by differences in shooting time and range time. The G1-10 women exhibited on average 12% slower speeds than the G1-10 men, and course time accounted for 93% of the total time difference of 13% between sexes. The average total hit rates were 92–93% among the G1-10 and 85% among the G21-30 in both sexes. In total, men shot on average 6 s faster than women. Course time is the most differentiating factor for overall biathlon performance between performance levels and sex in World Cup races. No sex difference in shooting performance was found.

Purpose: To investigate fluctuations in speed, work rate, and heart rate (HR) when cross-country ski skating across varying terrains at different endurance-training intensities. Methods: Seven male junior Norwegian skiers performed maximal-speed (V _max) tests in both flat and uphill terrains. Thereafter, 5-km sessions at low (LIT), moderate (MIT), and high intensity (HIT) were performed based on their own perception of intensity while monitored by a global navigation satellite system with integrated barometry and accompanying HR monitor. Results: Speed, HR, and rating of perceived exertion gradually increased from LIT to MIT and HIT, both for the total course and in flat and uphill terrains (all P < .05). Uphill work rates (214 [24] W, 298 [27] W, and 350 [54] W for LIT, MIT, and HIT, respectively) and the corresponding percentage of maximal HR (79.2% [6.1]%, 88.3% [2.4]%, and 91.0% [1.7]%) were higher than in flat terrain (159 [16] W, 206 [19] W, and 233 [72] W vs 72.3% [6.3]%, 83.2% [2.3]%, and 87.4% [2.0]% for LIT, MIT, and HIT, respectively) (all P < .01). In general, ∼13% point lower utilization of maximal work rate was reached in uphill than in flat terrain at all intensities (all P < .01). Conclusions: Cross-country ski training across varying terrains is clearly interval based in terms of speed, external work rate, and metabolic intensity for all endurance-training intensities. Although work rate and HR were highest in uphill terrain at all intensities, the utilization of maximal work rate was higher in flat terrain. This demonstrates the large potential for generating external work rate when uphill skiing and the corresponding downregulation of effort due to the metabolic limitations.

This study’s aim was to identify the effect of oscillation of torques in isometric tasks under identical mechanical conditions on the muscle synergies used. It was hypothesized that bi-functional muscles would play a lesser role in torque oscillation, because they would also generate an undesired oscillation. Thus, changes in muscle synergies were expected as a consequence of oscillation in torque generation. The effect of the trajectory of torque generation was investigated in dual-degrees-of-freedom submaximal isometric oscillation torque tasks at the elbow. The torques were flexion-extension and supination-pronation. Oscillation torques were compared with static torque generations at four torque positions during oscillation. Muscle activity was determined with surface electromyography. Compared with the static torque tasks, the oscillation tasks showed an overall increased muscle activity. The oscillation tasks, however, showed similar activity patterns and muscle synergies compared to the static composite tasks. It was found that the motor system is well able to control different orthogonal combinations of slow torque oscillations and constant torques by employing a single oscillating muscle synergy.