Effects of Resisted Sprint Training on Sprint Performance in High School Baseball Players

Abstract

Abstract:Resisted sprint training (RST) affects sprint speed in the acceleration phase, but there is no research regarding this for in adolescents. This study investigated the effects of RST on sprint speed and ground reaction force (GRF) in high school baseball players. Subjects were assigned to the resisted sprint group (RSG, n=10, loading 20% body mass), or the normal sprint group (NSG, n=9, without loading) and trained three days per week for eight weeks. Sprint speed [0-5, 5-10, 10-15, 15-20 and 0-20 meters (m)] and GRF [peak propulsive/resultant force, (PFpro/ PFres); impulse, (I); and ratio of force applied onto the ground (RF)] measured at the right and left foot at the start, the first step of the left foot (L1st), 5 m and 10m were assessed before and after training. In the RSG, a significant interaction was found for sprint speed at 0-5 m (p=0.028) and increased after training (p<0.0001). The 15-20 m sprint speed increased significantly in the NSG after training (p=0.022). The 0-20 m sprint speed increased significantly in both groups after training (RSG, p=0.001; NSG, p=0.041). Significant interactions were found for PFpro (p=0.015) and RF (p=0.0002) at the L1st in the RSG. PFpro (p=0.005), PFres (p=0.038) and RF (p=0.0002) at L1st increased significantly in the RSG. RST increased sprint speed in the early part of the acceleration phase by improving force production but prevented the improvement of sprint speed over 15 m. Combining RST and sprint training without loading improved sprint speed in the acceleration phase.

Resisted Sprint Training in Youth: The Effectiveness of Backward vs. Forward Sled Towing on Speed, Jumping, and Leg Compliance Measures in High-School Athletes

“…The results of this study demonstrate that BRS training is most beneficial in improving athletic performance in youth boys. Although previous studies using FRS training programmes have reported improvements in sprinting performance using loads ≤ 20% BM (2,31,36), the aim of this study was to evaluate the effects of using loads ≥ 20% BM and compare them with a novel training stimulus (i.e., BRS). The findings that BRS improved forward sprint performance and that relatively heavy FRS improved vertically oriented tasks (i.e., CMJ height and leg stiffness) indicate a transfer effect for specific sprint training methods exists.…”

“…On the other hand, minimal loading with sensible upper limits of 10% BM has been recommended for youth (29). Although suggestions have been made to limit RS loads to 10%, it has been shown that training with loads up to 20% results in improved force capabilities and sprinting performance in boys (36). In addition, findings from this research demonstrate that towing weighted sleds ranging from 20 to 55% BM can safely be used to overload BRS and FRS, minimize negative adaptations, and cause meaningful changes in a variety of athletic tasks in mid-PHV to post-PHV boys.…”

“…It is believed that RS improves an athlete's ability to apply propulsive forces more effectively and leads to adaptations in sprint acceleration ability (17). This specific sprint training method has been shown to be particularly beneficial for midpubescent and postpubescent youth (2,31,36). For example, six to weeks of RS training using loads ranging from 2.5 to 20% body mass (BM) has resulted in small to large increases in propulsive force production (31) and sprinting performances over 20 m (36) and 30 m (2,31).…”

“…This specific sprint training method has been shown to be particularly beneficial for midpubescent and postpubescent youth (2,31,36). For example, six to weeks of RS training using loads ranging from 2.5 to 20% body mass (BM) has resulted in small to large increases in propulsive force production (31) and sprinting performances over 20 m (36) and 30 m (2,31). Although these findings are promising for practitioners wishing to implement RS with youth, these results are limited to 3 known studies using RS towing weighted sleds up to 20% BM as a training stimulus (2,31,36).…”

“…For example, six to weeks of RS training using loads ranging from 2.5 to 20% body mass (BM) has resulted in small to large increases in propulsive force production (31) and sprinting performances over 20 m (36) and 30 m (2,31). Although these findings are promising for practitioners wishing to implement RS with youth, these results are limited to 3 known studies using RS towing weighted sleds up to 20% BM as a training stimulus (2,31,36). This is important because it has been recognised that loads >20% BM and up to 96% BM are most beneficial for improving peak power and acceleration performance in adults (7,24,30), yet the chronic influence of towing relatively greater loads has not yet been examined in youth.…”