ORIGINAL RESEARCH article
Front. Physiol.
Sec. Exercise Physiology
This article is part of the Research TopicAcute and Chronic Physiological Adaptations to Resistance Exercises Across Various Populations: Mechanisms and Practical ApplicationsView all 31 articles
Effect of Velocity Loss Squat Induced Post-activation Performance Enhancement on Lower Limb Explosive Power in Sprinters
Provisionally accepted
Jiawei Sun1
Lin Deng1
Shiyi Xu1Jianing Gu1
Jiayi Li2Ruofei Wang1Xinyu Lu1Nan Lou1Jianghua Zou1Zhanming Xu1*
Laikang Yu1*- 1Beijing Sport University, Beijing, China
- 2Huaqiao University, Quanzhou, China
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Background: This study aimed to identify the optimal velocity loss (VL) threshold during squats for inducing post-activation performance enhancement (PAPE) in track and field sprinters, with the goal of maximizing sprint performance. Methods: Twenty-four sprinters performed squat-based PAPE protocols using 85% 1RM (1 Repetition Maximum) across four VL thresholds (5%, 10%, 15%, and 20%). The 30-meter sprint and countermovement jump (CMJ) tests were administered at baseline and at 4, 8, 12, and 16 min post-intervention. Measurements included CMJ height, peak power, momentum, and the number of squats completed under each VL condition. Results: The 5% VL condition led to significant improvements in 30-meter sprint time at 4 min (F(1,47) = 7.292, P = 0.01, Cohen's d = -0.777) and 8 min (F(1,47) = 4.603, P = 0.037, Cohen's d = -0.615), along with increases in CMJ height (F(1,47) = 5.748, P = 0.021, Cohen's d = 0.69), peak power (F(1,47) = 5.585, P = 0.022, Cohen's d = 0.685), and momentum (F(1,47) = 6.462, P = 0.014, Cohen's d = 0.715). Under This is a provisional file, not the final typeset article the 10% VL condition, significant gains were observed in 4-min sprint performance (F(1,47) = 5.288, P = 0.026, Cohen's d = -0.656) and CMJ peak power at 4 min (F(1,47) = 5.585, P = 0.014, Cohen's d = 0.741) and 8 min (F(1,47) = 3.884, P = 0.022, Cohen's d = 0.687). The number of squats performed was significantly lower at 5% VL compared to other thresholds (P < 0.001). Conclusion: A velocity loss threshold of 5% during squats at 85% 1RM elicits a significant PAPE effect by 4 minutes post-exercise, with the fewest required repetitions. For practical application, a recovery interval of 4 to 8 min is recommended to optimize training outcomes in sprinters.
Keywords: Countermovement jump, lower limb explosive power, Post-activation performance enhancement, Post-activation potentiation, Sprinter, Velocity loss
Received: 14 Oct 2025; Accepted: 16 Feb 2026.
Copyright: © 2026 Sun, Deng, Xu, Gu, Li, Wang, Lu, Lou, Zou, Xu and Yu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Zhanming Xu
Laikang Yu
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