Effects of In-Season Subjective vs. Objective Autoregulation on Sprint-, Jump- and Power Performance in Professional Soccer Players
Abstract
ABSTRACTPurpose: The study aimed to compare the effects of subjective and objective autoregulation of strength training on sprint time, jump height and power in-season in professional soccer players. Methods: Sixteen players (24.6±3.5 years) from second highest national level in Norway completed a 10-week training period focusing on lower-limb exercises. They were randomized to a group that self-selected (SS) volume based on how they felt immediately before the strength training sessions, or an objectively autoregulated group (OA) that adjusted volume based on distance covered ≥5.5m/s (>420m,420-687m,>687m) during soccer matches preceding strength training. Pre- and post-measurements were sprint split times (0-30m), countermovement jump height (CMJ), and power (Pmax) in a pneumatic leg press device. Results: An independent samples t-test revealed no significant differences between groups in neither changes of leg press power (SS: 0.1±4.1% vs. OA: -0.9±6.3%, p=0.87), CMJ (SS: 4.3±8.9% vs. OA: 2.6±8.9%, p=0.70) or 0-30m sprint split times (SS: -2.2±4.8 to -0.62±2.05%, vs. OA: -2.46±3.51 to -0.86±1.86%, p>0.91-0.83). A paired samples ttest revealed no within-group changes from baseline. All participants pooled showed improvement tendencies in 0-5m sprint time (-2.3±4.2%, p=0.052), 15- and 20m sprint times (-1.1%, p=0.09 and -1.0 %, p=0.10, respectively), from baseline. Conclusion: Neither subjective SS nor OA of volume based on locomotive data from soccer matches improved any power-related measure, but one weekly strength training session seemed to be sufficient to maintain in-season power performance in professional soccer players. More research is warranted, with a larger sample size and training volume than in the present study.