Abstract
Aerobic performance is negatively impacted by tropical climate due to impairment of
thermoregulatory mechanisms. We tested the hypothesis that a torso application of
a 4% menthol solution would have the same effect on a best performance 10-km run as
an external use of cold water. Thirteen trained male athletes completed four outdoor
10-km runs (T=29.0±1.3°C, relative humidity 59.0±13.6%) wearing a tee-shirt soaked
every 2-km either in a cold (~6°C) or warm/ambient (~28°C) solution, consisting in
water or in a 4% menthol solution, (CTL, MENT-Amb, CLD and MENT-CLD). Run performances
were improved from 4.8 to 6.1% in CLD (51.4±5.5 min), MENT-Amb (52.2±5.9 min) and
MENT-CLD (51.4±5.1 min) conditions (vs. CTL, 55.4±8.4 min, P<0.05), without differences
between these three conditions, whereas heart rate (177±13bpm), body temperature (38.7±0.6°C)
and drink ingestion (356±170 g) were not modified. Thermal sensation after running
was lower in MENT-CLD (vs. CTL, P<0.01) and thermal acceptability was higher in CLD
and MENT-Amb (vs. CTL, P<0.05), but thermal comfort, feeling scale and rate of perceived
exertion remained unchanged. The use of menthol on skin enhances aerobic performance
in a tropical climate, and no differences in performance were observed between menthol
and traditional percooling strategies. However, combining both menthol and traditional
percooling brought no further improvements.
Key words
tropical climate - aerobic performance - running, menthol - external cooling