Comparing Acute Effects of Heavy Resistance, Plyometric, and Complex Training on Post-Activation Performance Enhancement in elite swimmers: A Randomized Controlled Trial

Zhili Ma¹Chuanbo Zheng²Tao Gao²Ziren Zhao³Xin Zheng³Ting Liao^2*Yong Tai Wang^4*

• ¹Chengdu University of Traditional Chinese Medicine, Chengdu, China
• ²Wuhan Sports University, Wuhan, China
• ³Chongqing Normal University, Chongqing, China
• ⁴University of Rochester, Rochester, United States

Background: Post-activation performance enhancement (PAPE) is an emerging strategy for optimizing pre-competition warm-up in elite swimming. However, substantial heterogeneity exists across studies due to inconsistent load standardization methodologies. Objective: This randomized controlled trial aimed to examine the acute effects of three PAPE training modalities, heavy resistance training (HRT), plyometric training (PLY), and complex training (COM), on swim start performance and lower body power in elite swimmers, utilizing session rating of perceived exertion (sRPE) for load equalization. Methods: Forty-seven first-class swimmers (mean age 21.21±0.69 years; training experience 8.08±0.91 years) were randomly allocated to control (n=11), heavy resistance training (n=11), plyometric training (n=12), or complex training (n=13) groups. All interventions were standardized to achieve equivalent session rating of perceived exertion-time load (sRPE-TL) of 70-80 arbitrary units. The primary outcome was 15-meter swim start time (T15m). Secondary outcomes included force platform variables (peak horizontal force, average propulsive force, propulsive impulse, take-off velocity) and land-based power measures (countermovement jump height and peak power). Performance assessments were conducted at 3, 6, 9, and 12 minutes post-intervention across four separate testing sessions. Effect sizes were calculated using Cohen's d for within-group pre-post comparisons. Results: Mixed-model ANOVA revealed significant group × time interactions for T15m (F(3,43)=2.339, P=0.024, η²p=0.14), peak horizontal force (F(3,43)=19.407, P<0.001, η²p=0.58), average propulsive force (F(3,43)=7.005, P<0.001, η²p=0.33), propulsive impulse (F(3,43)=21.777, P<0.001, η²p=0.60), take-off velocity (F(3,43)=23.148, P<0.001, η²p=0.62), CMJ height (F(3,43)=2.884, P=0.032, η²p=0.17), and peak power (F(3,43)=10.188, P<0.001, η²p=0.42). COM induced the largest improvements compared to CON, with T15m decresing by 3.00% (ES=1.79, P<0.001), peak horizontal force increasing by 5.14% (ES=4.95, P<0.001), average propulsive force by 8.48% (ES=1.71, P<0.001), propulsive impulse by 8.57% (ES=3.46, P<0.001), and take-off velocity by 6.41% (ES=3.06, P<0.001). Distinct temporal profiles emerged: PLY peaked at 6 minutes, HRT sustained effects through 12 minutes, while COM demonstrated optimal windows at 9-12 minutes. sRPE-TL standardization successfully eliminated between-group load variability (CV<8%, F(2,33)=1.23, P=0.297). Conclusions: Under sRPE-TL-standardized conditions, complex training elicited greater PAPE responses, with distinct optimal time windows among modalities (PLY: 6 min; HRT: 12 min; COM: 9-12 min), supporting individualized pre-race warm-up programming.