Effect of high-speed treadmill training with a body weight support system in a sport acceleration program with female soccer players.

Maximum running speed and acceleration are essential components in many sports. The identification of specific training protocols to maximize sprint speed would be useful knowledge for coaches and players. The purpose of this study was to determine the effect of a high-speed treadmill (HST) with the use of a body weight support (BWS) system in a 6-week sport acceleration program (SAP) on female soccer athlete's 40-yard sprint time and maximal isometric knee flexor and extensor strength. Two treatment groups and one control group were created. Both treatment groups participated in a 12-session SAP. The first treatment group (n = 12) used a BWS system while running on a HST; the second group (n = 12) used a standard treadmill (ST) with no BWS system. The participants of the control group (n = 8), NT, did not participate in a sports acceleration program and did not alter their exercise routines outside of the study. An analysis of covariance was performed using baseline measures as the covariate. The 40-yard sprint times for both treatment groups were shown to improve significantly compared with the control group (p < 0.001). Isometric knee flexor strength showed a greater increase in the ST group (p = 0.026) than in the other 2 groups, whereas knee extensor strengths did not show significant differences between treatment groups and control group (p > 0.05). Participants in the ST group had a much higher rate (66%) of shin splints and foot pain throughout the study than those in the HST (8%) and NT (0%) groups. These results can help high school coaches and athletes determine the optimal treadmill training regime.

Water treadmill parameters needed to obtain land treadmill intensities in runners.

PURPOSE: To establish water treadmill running parameters with shoes (WTR-S) and without water shoes (WTR-NS) needed to obtain known land treadmill running (LTR) cardiorespiratory responses. METHODS: Eighteen trained college-aged runners participated in three running conditions (LTR, WTR-S, and WTR-NS) where cardiorespiratory responses were measured. The primary variables of interest were VO2, HR, treadmill speed, and stride frequency (SF). These variables were assessed at 50%, 60%, 70%, and 80% equivalents of land VO2max for all three running conditions. RESULTS: Data were centered; so in the analysis, intercepts were calculated within the range of data. At an HR of 150 bpm, VO2 was significantly less (P < 0.05) during LTR (34.6 mL·kg(-1)·min(-1)) compared with WTR-S (37.5 mL·kg(-1)·min(-1)) and WTR-NS (37.2 mL·kg(-1)·min(-1)). HR was approximately 7 bpm less during WTR compared with LTR, although the metabolic demand (VO2) was similar. At a treadmill speed of 160.9 m·min(-1), SF during LTR was 23.6 strides per minute greater (P < 0.05) than that during WTR-S and 21.8 strides per minute greater than that during WTR-NS. Wearing water shoes increased VO2 by 4.12 mL·kg(-1)·min(-1) at any given water treadmill speed. CONCLUSIONS: To achieve metabolic oxygen demands equivalent to intensities from 50% to 80% of VO2max on LTR, WTR parameters have to be changed from those used on LTR. WTR is an effective alternative to LTR. Subjects were able to exercise on the water treadmill at intensities equivalent to 80% of their VO2max and 55% to 94% of their land HRmax. Individuals can select a treadmill speed during WTR that elicits an HR of approximately 7 bpm less than their LTR to obtain a cardiorespiratory overload equivalent to 50%, 60%, 70%, and 80% of their land VO2max.