Effects of Three Different Volumes of In-Water Warm-Up Protocols in Acute Physiologic Responses and 100 m Swimming Performance Across All Strokes.

Saini, AS, Sharma, SK, Kushwah, GS, Phukan, MI, McCabe, C, and Thapa, RK. Effects of three different volumes of in-water warm-up protocols in acute physiologic responses and 100 m swimming performance across all strokes. J Strength Cond Res 40(2): 191-197, 2026-This study examined the effects of 3 in-water warm-up (WU) protocols of varying volumes (600, 1,200, and 1,800 m) on acute physiologic responses and 100-m swimming performance across all strokes. Forty male national-level swimmers (21.0 ± 2.0 years) participated in a randomized crossover study, performing each WU protocol followed by a 100-m time trial in their respective strokes. Physiologic metrics, including blood lactate, temperature, heart rate, and rating of perceived exertion (RPE), were recorded. A repeated measures ANOVA was used to investigate the effects of the 3 protocols on physiologic and swimming performance across all the strokes. Results showed that the regular WU (1,200 m) led to significantly faster times in backstroke (65.56 ± 1.14 seconds vs 67.02 ± 1.20 seconds), breaststroke (70.73 ± 0.94 seconds vs 72.73 ± 0.94 seconds), and butterfly (58.64 ± 0.77 seconds vs 60.53 ± 0.86 seconds) than the long WU (1,800 m) ( p < 0.05). For the butterfly, the short WU (600 m) also resulted in significantly better swimming performance than the long WU. No significant differences were observed in freestyle performance among the 3 WU protocols, nor were there differences in heart rate across all strokes ( p > 0.05). Higher blood lactate and tympanic temperatures were observed after regular WU, while RPE was lowest after the short WU. This study emphasizes the importance of optimizing WU volumes based on stroke-specific demands in swimming. In addition, it also suggests practitioners to be cautious about using heart rate as a sole marker of WU effectiveness in swimming.