Cooling during Exercise in Temperate Conditions: Impact on Performance and Thermoregulation

Abstract

Exercise-induced increase in core body temperature may lead to the development of hyperthermia (>40.0°C) and/or decreased performance levels. This study examined the effects of wearing a cooling vest during a 5-km time trial on thermoregulatory responses and performance. 10 male masters athletes (42±10 years) performed a 5-km time trial on a motorized treadmill in a climate chamber (25°C, 55% relative humidity) with and without a cooling vest. Split times, heart rate, core-, skin- and cooling vest temperature were measured every 500 m. Subjects also rated thermal comfort and level of perceived exertion. The cooling vest significantly decreased heart rate (p<0.05), decreased skin temperature (p<0.001) and improved thermal comfort (p<0.005) during the time trial. Time to finish the 5-km time trial and pacing strategy did not differ between the control (1 246±96 s) and cooling vest condition (1 254±98 s, p=0.85). Additionally, thermoregulatory responses, maximum core body temperature and level of perceived exertion were not different across conditions (p=0.85, p=0.49, p=0.11, respectively). In conclusion, we demonstrated that wearing a cooling vest during exercise improves thermal comfort but does not enhance performance or decrease core body temperature in male masters athletes under temperate ambient conditions.

Effect of short‐term heat acclimation with permissive dehydration on thermoregulation and temperate exercise performance

“…Finally, the heat‐related performance decrement observed in temperate conditions is small relative to exercise under hotter conditions and the improved thermoregulatory capability may have been insufficient to meaningfully impact upon this. A recent study has shown that wearing a cooling vest did not significantly impact on exercise performance in temperate conditions (25 °C, 55% RH), despite reductions in heart rate, skin temperature and improved thermal comfort (Eijsvogels et al., ). It should be noted that while STHADe has been shown to be ergogenic under hot conditions (Garrett et al., ), ergogenic effects under temperate conditions have not been demonstrated and it may be that a longer HA program is necessary.…”

Cooling interventions for athletes: An overview of effectiveness, physiological mechanisms, and practical considerations

“…This observation is unexpected, because the thermal load is larger in hot ambient conditions, 58 which should facilitate the potential benefits of cooling. However, there is a large variation in performance benefits in the studies performed in moderate ambient conditions, ranging from a small non-significant negative effect (−0.6%, ES = 0.08) 49 to a very large positive effect (51%, ES = 1.17) 57 of per-cooling. This variation may possibly be explained by methodological differences in the exercise protocol and outcome measures, as a subjective outcome (rate of perceived exertion) was used as a surrogate for exercise intensity and may therefore influence the time to exhaustion 52 .…”

“…Due to practical feasibility and sporting regulations, less cooling techniques can be applied during exercise compared to pre-cooling. Consequently, the effects of per-cooling were investigated using cooling packs, 46-48 cooling vests, 49,50 cold water/ice slurry ingestion, 37,51 facial wind or water spray cooling 52,53 and menthol cooling 54-56 . Interestingly, menthol cooling could be applied as a mouth rinse, a gel on the face or as a spray on the clothing of the athlete.…”

“…2014 36 5-km running time trialCooling vest during exerciseNo difference in time trial performanceNo difference in Tgi25°C 55% rhWearing a cooling vest did not improve time trial performanceHsu et al. 2005 49 30-km cycling time trialHand cooling (22°C) during cycling6.6% improvement in exercise timeNo difference in Ttymp32°C 24% rhHand cooling improved 30-km cycling time trial performanceLuomala et al. 2012 37 70 min cycling trial (60% VO 2 max) with intermittent-sprints (80% VO 2 max)Ice vest applied after 30 min of exercise, until point of exhaustion21.5% improvement of exercise time until exhaustionNo change in Tc30°C 40% rhWearing an ice-vest during exercise enhances exercise performanceMinetti et al.…”

“…An explanation may relate to the cooling power of the used interventions. One study used an evaporative cooling vest (∼10°C), 49 while another study used cold water ingestion (10°C) to enhance performance 59 . The relatively high intervention temperature may be insufficient to elicit a performance benefit.…”