The effects of a 6-week strength training on critical velocity, anaerobic running distance, 30-m sprint and yo-yo intermittent running test performances in male soccer players

The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. Methods: two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. Results: after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p<0.001) with no significant changes in the SO group. 30-m sprint performance were slightly improved in the ST group with significantly decreased performance times identified in the SO group (p<0.001). Values for D' were slightly reduced in both groups (ST -44.5 m, 95% CI = -90.6 to 1.6; SO -42.6 m, 95% CI = -88.7 to 3.5). Conclusions: combining a 6-week moderate strength training with soccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer

Optimal V̇O2max-to-mass ratio for predicting 15 km performance among elite male cross-country skiers

Tomas Carlsson,1,2 Magnus Carlsson,1,2 Daniel Hammarstr&ouml;m,3 Bent R R&oslash;nnestad,3 Christer B Malm,2 Michail Tonkonogi1 1School of Education, Health and Social Studies, Dalarna University, Falun, 2Sports Medicine Unit, Ume&aring; University, Ume&aring;, Sweden; 3The Lillehammer Research Center for Medicine and Exercise Physiology, Lillehammer University College, Lillehammer, Norway Abstract: The aim of this study was 1) to validate the 0.5 body-mass exponent for maximal oxygen uptake (V̇O2max) as the optimal predictor of performance in a 15 km classical-technique skiing competition among elite male cross-country skiers and 2) to evaluate the influence of distance covered on the body-mass exponent for V̇O2max among elite male skiers. Twenty-four elite male skiers (age: 21.4&plusmn;3.3 years [mean &plusmn; standard deviation]) completed an incremental treadmill roller-skiing test to determine their V̇O2max. Performance data were collected from a 15 km classical-technique cross-country skiing competition performed on a 5 km course. Power-function modeling (ie, an allometric scaling approach) was used to establish the optimal body-mass exponent for V̇O2max to predict the skiing performance. The optimal power-function models were found to be race speed = 8.83 &bull; (V̇O2max m-0.53)0.66 and lap speed = 5.89 &bull; (V̇O2max m-(0.49+0.018lap))0.43e0.010age, which explained 69% and 81% of the variance in skiing speed, respectively. All the variables contributed to the models. Based on the validation results, it may be recommended that V̇O2max divided by the square root of body mass (mL &bull; min-1 &bull; kg-0.5) should be used when elite male skiers&rsquo; performance capability in 15 km classical-technique races is evaluated. Moreover, the body-mass exponent for V̇O2max was demonstrated to be influenced by the distance covered, indicating that heavier skiers have a more pronounced positive pacing profile (ie, race speed gradually decreasing throughout the race) compared to that of lighter skiers. Keywords: allometric scaling, maximal oxygen uptake, cross-country skiing, pacin

Improvement of Ice Hockey Players' On-Ice Sprint With Combined Plyometric and Strength Training.

BACKGROUND: Combined plyometric and strength training has previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training have not previously been compared with the effects of strength training only. PURPOSE: To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with those of strength training only. METHODS: Eighteen participants were randomly assigned to 2 groups that completed 5 strength-training sessions/wk for 8 wk. One group included plyometric exercises at the start of 3 sessions/wk (PLY+ST), and the other group included core exercises in the same sessions (ST). Tests of 10- and 35-m skating sprints, horizontal jumping, 1-repetition-maximum (1 RM) squat, skating multistage aerobic test (SMAT), maximal oxygen consumption, repeated cycle sprints, and body composition were performed before and after the intervention. RESULTS: The participants increased their 1RM squat, lean mass, and body mass (P < .05), with no difference between the groups. Furthermore, they improved their 3×broad jump, repeated cycle sprint, and SMAT performance (P < .05), with no difference between the groups. PLY+ST gained a larger improvement in 10-m on-ice sprint performance than ST (P < .025). CONCLUSION: Combining plyometric and strength training for 8 wk was superior to strength training alone at improving 10-m on-ice sprint performance in high-level ice hockey players

High-load resistance exercise with superimposed vibration and vascular occlusion increases critical power, capillaries and lean mass in endurance-trained men

PURPOSE: It is a widely accepted premise in the scientific community and by athletes alike, that adding resistance exercise to a regular regimen of endurance training increases endurance performance in endurance-trained men. However, critical power (CP), capillarization, and myofiber size remain unaffected by this addition. Therefore, we tested whether the superimposition of resistance exercise with whole-body vibration and vascular occlusion (vibroX) would improve these variables in endurance-trained males relative to resistance exercise alone. METHODS: Twenty-one young, endurance-trained males were randomly assigned either to a vibroX (n = 11) or resistance (n = 10) training group. Both groups trained in a progressive mode twice a week for 8 weeks. Pre and post training, histochemical muscle characteristics, thigh muscle size, endurance and strength parameters were determined. RESULTS: vibroX increased CP (P = 0.001), overall capillary-to-fiber ratio (P = 0.001) and thigh lean mass (P < 0.001), while these parameters were unaffected by resistance training. The gain in CP by vibroX was positively correlated with the gain in capillarization (R (2) = 0.605, P = 0.008), and the gain in thigh lean mass was paralleled by increases in MyHC-1 and MyHC-2 fiber cross-sectional areas and strength. Maximum voluntary torque and the finite work capacity above CP (W') increased significantly only following resistance training. CONCLUSIONS: We achieved a proof of concept by demonstrating that modification of resistance exercise by superimposing side-alternating whole-body vibration and sustained vascular occlusion induced further improvements in CP, capillarization and hypertrophy, all of which were not observed with resistance training alone