Our body has a heat regulation system that prevents us from overheating, either during physical exercise or on a hot summer day; one of these physiological processes is sweat. But who sweats more, men or women? Research has evaluated sex differences in the body’s response to heat.
When the outside temperature increases, signals are sent to the hypothalamus of the brain that responds to changes in temperature by making physiological adjustments to maintain that ideal internal temperature, hence, to cool us down, the body produces sweat. Until now, it was believed that men and women responded differently to increased heat due to the physical characteristics of each gender.
However, the study carried out by scientists from the University of Wollongong (Australia) and the Prefectural College of Nursing in Mie (Japan) challenges this belief. The researchers hypothesized that the response to heat would change depending on the relationship between body surface area and mass , and not on sex.
The study evaluated the vasomotor and sudomotor functions of 60 healthy participants (36 men and 24 women) of various body shapes and sizes. The participants were divided into four groups: trained, untrained women, trained and untrained men. The volunteers completed two physical tasks at 28 ° C and 36% relative humidity ; They rested for 20 minutes and then biked at a steady pace for 45 minutes. Later they also cycled at a higher intensity. Under these conditions, the body naturally tries to prevent the body temperature from rising thanks to sweat and increased blood flow.
The experiments revealed that body mass was a significant factor determining vasomotor and sudomotor responses in both men and women. The researchers considered morphological differences between genders: these accounted for less than 5% of the changes observed between individuals, as opposed to 10-48% for morphological changes. The same body temperature changes occurred in all participants, regardless of their sex.
In addition, the study found that women and men with a smaller body size (with more surface area per kilogram of body mass), lose heat by increasing blood circulation instead of sweating. In comparison, people with larger bodies rely more heavily on sweating.
“Gender was believed to influence skin sweating and blood flow during heat stress, and we found that these heat loss responses are in fact independent of gender during exercise under conditions where the body can successfully regulate their temperature “, clarifies Sean Notley, leader of the work.
The study has been published in the journal Experimental Physiology.
