Heated garments and dryland activation routines: The keys to improving sprint swimming performance?

Introduction In competitive swimming after the pool warm-up, swimmers must change into their racing suit, confer with their coach and report to marshalling ~15-20 min prior to race start, thus transition phases of 30-45 min are not uncommon. There is a risk of a significant decline in body temperature with a long transition phase given that body temperatures can decline immediately following exercise cessation, with a significant reduction evident after ~15-20 min of recovery (Mohr et al.,2004). We postulate that this decline in body temperature during transition could be ameliorated by combining an athlete’s sport-specific warm-up (i.e. pool warm-up) with passive heating and additional active warm-up strategies. Methods In a counterbalanced, repeated measures cross-over design 39 national and internationally competitive swimmers (age:20 ± 2 yr; n=19 males:stature 1.85 ± 0.04 m, 79.4 ± 6.4 kg;n=20 females:1.74 ± 0.7 m, 65.6 ± 6.3 kg;mean ± standard deviation) completed a standardised pool warm-up (1550 m) followed by a 30 min transition and a 100 m freestyle (n=29) or breaststroke (n=10) time-trial. Swimmers completed two different warm-up strategies during transition: CON, remained seated wearing a conventional tracksuit jacket and pants, or COMBO, wore an insulated tracksuit jacket (freestyle) or pants (breaststroke) with integrated heating elements and performed a 5 min dryland-based exercise routine. Swimming time-trial performance, core temperature, capillary blood lactate and lower-body power output were assessed. Time variables were normalised relative to the CON (control) condition. Results The COMBO warm-up yielded a 0.30 ± 0.19%;mean ± 90% confidence limits, p=0.04 faster 100 m time-trial performance than CON. Start times to 15 m were also faster for COMBO (-0.10 ± 0.06%, p=0.02) compared to CON. Core temperature declined less (p=0.02) during transition with COMBO (-0.27 ± 0.08°C) than CON (-0.43 ± 0.06°C). Lower-body peak power output immediately prior to time-trial commencement (p=0.89) and post time-trial blood lactate concentration (p=0.66) were not significantly different between conditions. Discussion Sprint swimming performance in national and international level swimmers can be substantially enhanced by combining a traditional pool-based warm-up with the application of heated garments, and the completion of a brief dryland-based exercise routine, during a lengthy transition phase. Attenuation of the decline in core temperature and an improvement in start time appear as the likely mechanisms responsible for faster time-trial performance.