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.
Key words
cooling vest - core body temperature - endurance exercise - athletes - time trial
- precooling
