The Physiological
Society
Sex differences in
heat loss responses are dependent on body size and not sex, meaning that larger
individuals sweat more than smaller ones during cycle exercise in warm and
tolerable conditions.
That's what research
published in Experimental Physiology shows.
The body cools itself
down in two main ways: sweating and increasing circulation to the skin's
surface.
Body shape and size
dictates which of these two is relied upon for heat loss.
The study found that smaller males and females with more surface area per kilogram of body mass are more dependent on heat loss through increasing circulation and less dependent upon sweating.
These findings by
scientists from the University of Wollongong in Australia and Mie Prefectural
College of Nursing in Japan call into question the conventional belief that
women and men always respond differently to heat stress.
They performed two
trials (one of light exercise and the other of moderate) at 28 degrees Celsius
and 36% humidity.
These are conditions
where the body is able to mitigate the additional heat produced during exercise
and prevent further rises in body temperature by increasing sweating and blood
flow to the skin.
The same body
temperature changes were observed in all participants within each trial
regardless of sex.
Lead author Sean
Notley said: 'Gender has long been thought to influence sweating and skin blood
flow during heat stress. We found that these heat loss responses are, in fact,
gender independent during exercise in conditions where the body can
successfully regulate its temperature.'