Influence of post-warm-up recovery time on swim performance in international swimmers

Objectives: Swimmers must enter a marshalling call-room 20. min prior to racing, which results in some swimmers completing their warm-up 45. min pre-race. Since a recovery period longer than 15-20. min may prove problematic, this study examined 200. m freestyle performance after a 20 and 45. min post-warm-up recovery period. Design: Eight international swimmers completed this randomised and counter-balanced study. Methods: After a standardised warm-up, swimmers rested for either 20 (20min) or 45min (45min) prior to completing a 200m freestyle time-trial (TT). Core temperature (Tcore), blood lactate (BL), heart rate and rate of perceived exertion (RPE) were recorded at baseline, post-warm-up, pre-TT, immediately post-TT and at 3min post-TT. Results: Tcore was similar after the warm-up under both conditions, however, at pre-TT Tcore was greater under 20min (mean±SD; 20min 37.8±0.2 vs. 45min 37.5±0.2°C; P=0.002). BL was similar between conditions at all-time points before the TT (P>0.05). Swimmers demonstrated a 1.5±1.1% improvement in performance under 20min (20min 125.74±3.64 vs. 45min 127.60±3.55s; P=0.01). Tcore was similar between conditions at immediately post-TT and 3min post-TT (P>0.05), however, BL was higher at these time points under 20min (P<0.05). Heart rate and RPE were similar between conditions at all-time points (P>0.05). Conclusions: 200m freestyle performance is faster 20min post-warm-up when compared to 45min probably due to better Tcore maintenance. This has implications for swim race preparation as warm-up procedures should be completed close to entering the pre-race call room, in order to maintain elevated core temperature