Your bra size affects how much you sweat, and that’s not what you might think

A study from the University of Southampton has found a surprising link between breast size and the amount of sweat produced by the breasts during exercise.

The study examined 22 women of different ages and breast sizes as they ran in a warm climate chamber. This measured how much sweat they produced over their chest, how much heat their body produced and how many sweat glands they had on different parts of their body. breasts.

The study is published in the news Experimental Physiology.

Sweat production is mainly influenced by factors such as body size, metabolism and environmental conditions. However, the research team hypothesized that breast size could also influence both sweat production across the chest and comfort during physical activities.

The research, conducted by Hannah Blount – a postdoctoral researcher in thermal physiology at the university’s ThermosenseLab – found that larger breasts have fewer sweat glands, meaning they produce less sweat during exercise.

She said: “More than 85% of women consider a sports bra to be an essential part of their training, but it’s actually very difficult to find one that is comfortable and supportive, so many women struggle with this. Our thought process was to looking at how sports bras provide support and comfort to women with different breast sizes, especially in hot conditions, when women are more likely to experience issues such as chafing and significant sweat build-up in the bra.

“Specifically, we were interested in understanding how sweat gland density and local sweat rate change in women with different breast sizes, because that determines how much sweat ends up in the sports bra. This is where we got the most exciting finding, because our results indicated that Women with larger breasts had fewer sweat glands, and so they produced less sweat over their breasts. We can now use this fundamental knowledge to design sportswear that takes into account the needs of women with different breast sizes.’

The experiments were carried out in ThermosenseLab’s state-of-the-art environmental chamber, which is housed in the NIHR (National Institute for Health and Care Research) Southampton Clinical Research Facility, at University Hospital Southampton.

Women who took part were asked to jog for 45 minutes in 32 degrees Celsius heat while their sweat production was monitored at the chest. 3D scanning was used to calculate breast surface area, while sweat gland density was measured using iodine-infused paper that, when placed on the skin, reacts with the chemicals in sweat.

Dr. Davide Filingeri, associate professor of thermal physiology and international leading expert in the neurophysiology of human skin moisture sensing, said: “Women are a group of individuals who undergo unique anatomical, physiological and hormonal changes throughout their lives. Consider the impact of the menstrual cycle, pregnancy and menopause, all of which influence a woman’s heat tolerance, thermal sensitivity and comfort. As such, Hannah’s research into the unique and evolving ‘thermal needs’ of women’s bodies has the potential to drive person-centred innovation. field of sportswear which will ultimately help women thrive in our warming climate.”

Blount added: “We’re becoming more sedentary as a society, so if we can do something to help women become more active while making sport more accessible, then that’s really exciting.”