Effects of Different Loading Conditions During Resisted Sprint Training on Sprint Performance.

ABSTRACT: Rodríguez-Rosell, D, Sáez de Villarreal, E, Mora-Custodio, R, Asián-Clemente, JA, Bachero-Mena, B, Loturco, I, and Pareja-Blanco, F. Effects of different loading conditions during resisted sprint training on sprint performance. J Strength Cond Res 36(10): 2725-2732, 2022-The aim of this study was to compare the effects of 5 loading conditions (0, 20, 40, 60, and 80% of body mass [BM]) during weighted sled sprint training on unresisted and resisted sprint performance and jump ability. Sixty physically active men were randomly assigned into 5 groups according to the overload used during sled sprint training: 0% (G0%, n = 12), 20% (G20%, n = 12), 40% (G40%, n = 12), 60% (G60%, n = 12), and 80% BM (G80%, n = 12). Pretraining and post-training assessments included: countermovement jump (CMJ), 30-m sprint without extra load, and 20-m sprint with 20, 40, 60, and 80% BM. All 5 experimental groups trained once a week for a period of 8 weeks completing the same training program (number of sessions, number of bouts, running distance in each sprint, rest intervals between repetitions, and total running distance), but with different sled loads (0, 20, 40, 60, and 80% BM). There was a significant "time × group" interaction for resisted sprint performance at 80% BM condition, where the G40% group attained improvements in performance and G80% worsened. Moreover, G40% increased performance in unresisted and the rest of loading conditions. In addition, G0% and G60% showed statistically significant increases in unresisted sprint performance. No relevant changes were observed in the other experimental groups. All groups showed significant improvements ( p < 0.05-0.001) in CMJ height. Therefore, our findings suggest that resisted sprint training with moderate loads (i.e., 40% BM) may have a positive effect on unresisted and resisted sprint performance.

Combined Squat and Light-Load Resisted Sprint Training for Improving Athletic Performance.

ABSTRACT: Pareja-Blanco, F, Asián-Clemente, JA, and Sáez de Villarreal, E. Combined squat and light-load resisted sprint training for improving athletic performance. J Strength Cond Res 35(9): 2457-2463, 2021-This study aimed to analyze the effects of 5 training methods: squat (SQ), light-load sled towing (LST), heavy-load sled towing (HST), squat combined with LST (SQ + LST), and squat combined with HST (SQ + HST) on physical performance. Ninety-one physically active men were randomly assigned to one of the aforementioned training methods or a control group. Before and after the training period, a battery of tests was completed: 30-m sprint; change of direction (COD); countermovement jump (CMJ) and Abalakov jump (ABK); and estimated 1 repetition maximum (1RM) in squat. Training took place once per week for 8 weeks. SQ trained the squat exercise, HST trained resisted sprints with 80% body mass (BM) load, LST trained resisted sprints with 12.5% BM load, SQ + HST combined squat with 80% BM load resisted sprint, and SQ + LST combined squat with 12.5% BM load resisted sprint. The loads used in squat ranged from 40 to 55% 1RM. After the training program, SQ + LST showed improvements in 0- to 30-, 10- to 20-, and 10- to 30-m sprint times, whereas SQ + HST did not achieve significant enhancements over any sprint time. LST and HST improved over 0-20 and 10-30 m, respectively. SQ showed improvements in 20- to 30-m sprint time. Change of direction and CMJ performance were increased for HST, SQ + HST, and SQ + LST, whereas only SQ + LST improved ABK height. SQ, HST, SQ + HST, and SQ + LST increased 1RM. Squat training with low/moderate loads combined with LST (12.5% BM) may be an effective stimulus for improving leg strength, jump ability, COD, and sprint performance.

Effects of Unloaded Sprint and Heavy Sled Training on Sprint Performance in Physically Active Women.

PURPOSE: This study aimed to compare the effects of unresisted versus heavy sled sprint training (0% vs 40% body mass [BM]) on sprint performance in women. Moreover, the effects of the aforementioned loads on resisted sprint and jump performance were analyzed. METHODS: Twenty-eight physically active women were randomly allocated into 2 groups: unloaded sprint training group (G0%, n = 14), and resisted sprint training with 40% BM group (G40%, n = 14). Pretraining and posttraining assessments included countermovement jump, unloaded 30-m sprint, and 20-m sprint with 20%, 40%, 60%, and 80% BM. Times to cover 0 to 10 (T10), 0 to 20 (T20), 0 to 30 (T30), 10 to 20 (T10-20), 20 to 30 (T20-30), and 10 to 30 m (T10-30) were recorded. Both groups were trained once a week for 8 weeks and completed the same training program, but with different loads (0% vs 40% BM). RESULTS: No significant time × group interactions were observed. For unloaded sprint performance, G0% showed significant (P = .027) decreases only in T10-20, while G40% attained significant decreases in T30 (P = .021), T10-30 (P = .015), and T20-30 (P = .003). Regarding resisted sprint performance, G0% showed significant (P = .010) improvements only for the 20% BM condition. The G40% group attained significant improvements in all loading conditions (20%, 40%, 60%, and 80% BM). Both groups showed significant improvements (P < .001) in countermovement jump height. CONCLUSIONS: In physically active women, no significant differences in sprint and countermovement jump performance were detected after 8 weeks of resisted and unresisted sprint training programs. Future studies should, therefore, be devoted to how sprint training should be individualized to maximize performance.

Is Physical Performance a Differentiating Element between More or Less Successful Football Teams?

This study investigated the time-motion characteristics of football teams in the Spanish first division, in relation to their final competitive level as defined by league position (Champions League, Europa League, Upper mid-table, lower mid-table and relegation). Match observations (n = 9641) were collected using a multiple-camera computerized tracking system during the 2013-2014 competitive season. The following match parameters were analyzed: total distance, relative distance (m·min-1), distance < 14 km·h-1, >14 km·h-1, between 14-21 km·h-1, >21 km·h-1, and >24 km·h-1. Total distance and distance at different velocities (>14, 21, and 24 km·h-1) in and out of ball possession were also analyzed. A repeated analysis of variance and a comparison of effect sizes were carried out to compare the performance of the teams. The analysis of the data showed differences in physical performance characteristics between competitive levels. The volume of distance covered in the variables analyzed did not relate to success in soccer. Both successful and unsuccessful teams presented the same running requirements at higher velocities. These findings provide valuable information about the physical demands of the running requirements according to their final position in the league table.