Relationship Between Internal Load Indicators and Changes on Intermittent Performance After the Preseason in Professional Soccer Players.

The aim of this study was to examine the effects of accumulated internal training load (ITL) during the preseason (4 weeks) on changes in the intermittent performance, in a professional soccer team. Twelve professionals soccer players (Mean ± SD age: 27.7 ± 4.3 years; height: 177.1 ± 6.2 cm; body mass: 73.1 ± 5.2 kg; % body fat [Faulkner]: 10.2 ± 1.2) belonging to a Spanish second division team (2013-2014) participated in this study. The 30-15 intermittent fitness test was performed before and after the preseason, and the speed for the last period completed by each player was recorded (VIFT). During the preseason, the team alternated practice of training sessions (TRNs) with friendly matches (FMs). Session rating of perceived exertion (sRPE), heart rate (HR), and HR reserve were analyzed every TRN and FM to calculate ITL (ITL: sRPE-TL, Edward's-TL and Edward's-TLres). The players' VIFT substantially increased after the preseason period (20.1 ± 0.8 vs. 21.1 ± 0.8 km·h; effect size [ES] = 1.15 ± 0.25; almost certainly). The average value of sRPE throughout FMs was substantially greater than the value of the TRNs (7.4 ± 0.9 vs. 5.25 ± 0.2; ES = 2.31 ± 2.45; almost certainly). sRPE-TL, practice volume, and sum of RPE during the preseason were positively and largely correlated (r = 0.70-0.75) with changes on intermittent performance. No relationships were found between HR-derived measures of exercise load and changes on intermittent fitness. The present results suggest that practice volume and subjective measures of TL, related better than HR-based TL methods to changes on intermittent performance after the preseason, in professional soccer players.

The High-Pull Exercise: A Comparison Between a VersaPulley Flywheel Device and the Free Weight.

The aim of this study was to examine the kinematics and kinetics (force, velocity, and acceleration) and blood lactate concentration with the VersaPulley (VP) device in comparison with free-weight (FW) exercise at a similar external load. Fifteen rugby players randomly performed 2 training sessions of 6 sets of 6 repetitions with 20 s of recovery between sets of the high-pull exercise with the VP and the FW. The training sessions were separated by 72 h. Barbell displacement (cm), peak velocity (m/s), peak acceleration (m/s2), mean propulsive velocity (m/s), mean propulsive acceleration (m/s2), propulsive phase (%), and mean and maximal force (N) were continuously recorded during each repetition. Blood lactate concentration was measured after each training session (end) and 3 min and 5 min later. Barbell displacement (+4.8%, small ES), peak velocity (+4.5% small ES), mean propulsive acceleration (+8.8%, small ES), and eccentric force (+26.7, large ES) were substantially higher with VP than with FW. Blood lactate concentration was also greater after the VP exercise (end +32.9%, 3 min later +36%, 5 min later +33.8%; large ES). Maximal concentric force was substantially higher with FW than VP during the 6th set (+6.4%, small ES). In the cohort and exercise investigated in the current study, VP training can be considered an efficient training device to induce an accentuated eccentric overload and augmented metabolic demands (ie, blood lactate concentration).

Comparison of the effect of repeated-sprint training combined with two different methods of strength training on young soccer players.

The aim of this study was to assess the effect of combining repeated-sprint training with 2 different methods of muscle strength training on physical performance variables in young players. Twenty-one soccer players with mean (± SD) age of 18.1 (± 0.8) years, weight 69.9 (± 6.5) kg, and height 177.1 (± 5.7) cm, and competing in U-19 category, were randomly assigned to 2 experimental groups: squat group (SG: n = 10) and take-off group (TG: n = 11). Intervention in both groups consisted of the combination of a weekly session of repeated-sprint training (the same for both groups), with 2 weekly sessions of strength training (different for each group), for 8 weeks in the final period of the season. The strength sessions for the SG consisted of conducting a series of full squats executed at maximum velocity in the concentric phase. Intervention in the TG was the performance of 2 specific strength exercises (take-offs and change of direction), with measurements taken before and after consideration of the following variables: repeated-sprint ability (RSA), yo-yo intermittent recovery test level 1 (YYIRT1), countermovement jump (CMJ), and average velocity in full squat progressive loads test. The SG improved CMJ height in 5.28% (p ≤ 0.05) and FS37.5-47.5-67.5 (p ≤ 0.05), whereas the TG improved FS17.5-27.5-37.5-47.5-67.5 (p ≤ 0.05). There were no significant changes in the values of RSA or YYIRT1 in either group. The results seem to show that the combination of a weekly session of repeated-sprint training with 2 weekly sessions of strength training could be an insufficient stimulus to improve RSA in the final period of the season.

Running demands and heart rate responses in men Rugby Sevens.

The purpose of this study was to examine match running performance and exercise intensity in a Rugby Sevens (7s) team during competitive club-level matches. Time-motion analyses (global position system) were performed on 7 male rugby players during 5 competitive matches in a 2-day tournament. The players covered an average distance of 1,580.8 ± 146.3 m per game (14 minutes). Over this distance, 34.8% (549.7 ± 79.1 m) was spent standing and walking, 26.2% (414.8 ± 105.1 m) jogging, 9.8% (154.6 ± 53.5 m) cruising, 15.5% (244.5 ± 80.1 m) striding, 5% (79.5 ± 37.2 m) high-intensity running, and 8.7% (137.7 ± 84.9 m) sprinting. The average maximal distance of sprints, the number of sprints, the minimum distance of sprint, and the mean sprint distance over the game were 29.5 ± 11.7 m, 7.4 ± 3.9 sprints, 9.1 ± 5.7 m, and 18 ± 7.6 m, respectively. The player's work-to-rest ratio was 1:0.5. For over 75% of the game, the players were exposed to heart rates (HRs) >80% of their maximal HR. There were no statistical differences between the first and second halves in any of the variables analyzed. This study indicates that the physical demands of Rugby 7s are quite different from those encountered in other rugby codes and that the training regimes need to meet the increased overall running demands, the augmented high-intensity running actions, and the reduced work-to-rest ratios.