Ergogenic Effects of Intermittent Hand Cooling on High-Intensity Resistance Exercise Performance: A Placebo-Controlled Crossover Study

ABSTRACT: Wang, A, Fu, W, Shen, B, and Hurr, C. Ergogenic effects of intermittent hand cooling on high-intensity resistance exercise performance: A placebo-controlled crossover study. J Strength Cond Res 40(6): e562-e570, 2026-Intermittent peripheral cooling has been proposed as an ergogenic strategy to enhance resistance exercise performance. However, the contribution of placebo effects to its benefits remains unclear. This study examined the effects of hand cooling on exercise performance, neuromuscular activation, and perceived exertion during high-intensity biceps curl exercise, using a placebo-controlled design. Fourteen recreationally trained men (27.4 ± 2.3 years) completed 4 sets of bilateral biceps curl exercise to failure at 70% one-repetition maximum under 3 randomized conditions: full-hand cold-water immersion (10° C, COOL), thermoneutral immersion with placebo induction (SHAM), and thermoneutral control (CON). Cooling or thermoneutral immersion was applied for 60 seconds during each 90-second interset rest period. Total exercise volume was significantly greater in the COOL condition (1,092.3 ± 238.1 kg) compared with CON (892.2 ± 221.2 kg, p = 0.002) and SHAM (946.3 ± 226.7 kg, p = 0.013). The SHAM condition also improved volume compared with CON ( p = 0.003). The COOL condition enhanced mean and peak electromyography amplitude during sets 2‒4, and resulted in significantly lower rating of perceived exertion from set 2 onward ( p < 0.05). Palm temperature was significantly reduced with COOL; no group differences were observed for barbell velocity or heart rate. Hand cooling enhanced resistance exercise performance and neuromuscular activation without increasing perceived exertion. The SHAM condition also improved performance, indicating a partial placebo effect. These findings suggest that both physiological and psychological mechanisms contribute to the ergogenic benefits of hand cooling during resistance training.