Reliability of the Maximal Resisted Sprint Load Test and Relationships With Performance Measures and Anthropometric Profile in Female Field Sport Athletes

Petrakos, G, Tynan, NC, Vallely-Farrell, AM, Kiely, C, Boudhar, A, and Egan, B. Reliability of the maximal resisted sprint load test and relationships with performance measures and anthropometric profile in female field sport athletes. J Strength Cond Res 33(6): 1704-1714, 2019-Resisted sled sprint (RSS) training is an effective modality for the improvement of linear sprint speed. Previous methods of RSS load prescription, e.g., an absolute load or as a percentage of body mass (%BM), do not account for interindividual differences in strength, power, or speed characteristics, although the "maximum resisted sled load" (MRSL) method of RSS load prescription may provide a solution. Maximum resisted sled load is defined as the final RSS load before an athlete can no longer accelerate between 2 phases (10-15 and 15-20 m) of a 20-m linear sprint. However, the MRSL test has not been analyzed for reliability. In addition, MRSL performance has not been compared with the outcome of other performance tests. The primary aim of this study was to investigate the reliability of the MRSL testing protocol in female field sport athletes. Participants (age, 20.8 ± 1.9 years; body mass, 64.3 ± 8.4 kg; height, 1.66 ± 0.65 m) tested for anthropometric measurements, strength and power performance testing, and twice for MRSL. Maximum resisted sled load values ranged from 20.7 to 58.9% BM. Maximum resisted sled load test-retest reliability intraclass correlation coefficient, confidence intervals, and coefficient of variations were 0.95, 0.85-0.98, and 7.6%, respectively. Maximum resisted sled load was"moderately" and "strongly" correlated with a number of anthropometric and performance tests (p ≤ 0.05), including percentage fat free mass, countermovement jump, loaded countermovement jump, rate of force development, horizontal jump, and horizontal bound performance. Maximum resisted sled load is a reliable measure for determining the RSS load at which an individual can no longer accelerate during a single RSS effort over 0-20 m. Maximum resisted sled load also accounts for interindividual variation in body composition, power, and speed characteristics of female field sport players.