Faster Futsal Players Perceive Higher Training Loads and Present Greater Decreases in Sprinting Speed During the Preseason.

The aims of this study were to assess the speed-power characteristics of professional futsal players before and after a 9-week preseason and to explore possible relationships with internal training loads. Ten under-20 professional Brazilian futsal players performed unloaded (squat jump [SJ] and countermovement jump [CMJ]) and loaded (jump squat [JS]) jumps and a 20-m sprint test before and after the preseason. Weekly training loads as measured by session rating of perceived exertion (s-RPE) varied between 2,179 and 5,519 a.u. The magnitude-based inference statistics revealed that performance in the SJ, CMJ, and 20-m sprint very likely decreased (effect size [ES] = -0.64, -0.49, and -0.92, respectively), whereas mean propulsive power in the JS likely increased (ES = 0.42) in response to the preseason. The Pearson coefficient of correlation between velocity in the 20 m sprint test and s-RPE during the first 2 weeks of training was 0.66 (p ≤ 0.05) while no significant correlation was detected between total s-RPE (i.e., 9 weeks) and changes in the power-speed tests. The baseline 20-m sprint velocity was very largely and inversely (r = -0.90) correlated with the change in the 20-m sprint performance. In conclusion, futsal preseason training leads to impaired unloaded vertical jump and sprint test performance, with speed decreasing more in faster than slower players. In addition, because of the large correlation between baseline sprint ability and s-RPE, coaches are advised to assess sprinting performance at the beginning of the preseason to finely adjust the training stimuli to each athlete.