Why are we sweating?

We are special. Along with luscious locks, mammary glands, and a neocortex, we are one of the only groups that sweat. Our stinky glands are a common characteristic among mammals, providing evidence of shared ancestry. Yet, some perspire more than others. I recall a Thai hostel owner peering at me suspiciously, removing a drenched flannel from my face, and asking, ‘You look like me… but why you sweat so much?’

Sweating is evaporative heat loss, from a salty and urea-tinged solution, by sweat glands in our skin. Its purpose is temperature regulation. Heat raises our temperature, and thermoreceptors (sensitive nerve endings) detect this rise, notifying the brain. Our internal thermostat- the hypothalamus- sends impulses to sudoriferous (sweat) glands, which absorb liquid from tissue fluid, pouring it onto the skin. It evaporates and body temperature decreases. Cooling occurs because water molecules carry energy away in the liquid-to-gas reaction- 2.43kj of heat energy is required to change 1g of sweat into vapour. Since evaporation of sweat depends on air water vapour (humidity), and air movement (wind), victims may die in hot, humid, still conditions. But fear not. Sweating is due to our autonomous nervous system- a reflex action independent of direct messages from our brain! We are usually relieved at an optimum 37°c.

Or are we? The founder of the International Hyperhidrosis (excessive sweating) Society claimed that men produce 4 times more sweat than women per day, despite having the same number of odourous glands. Although fitness journals report that women sweat more efficiently, and tolerate higher temperatures. Athletes sweat SOONER and MORE during exercise, since continuous sweating to prevent overheating trains the body to be more efficient. This can reach almost 2L per hour. Conversely, extra subcutaneous fat stimulates greater sweating, and obese people use more energy to complete physical tasks, with more body mass to cool, adding to the overall amount of cooling required.

Familiar with coffee/cheese sweats? Diet can severely agonise our thermoregulatory machine. How to Stop Excessive Sweating in 14 Days warns that spicy foods, trans-fats, alcohol, and caffeine encourage sweat to ooze. Chemically altered trans-fats, e.g. fried foods, incite havoc in cell metabolism, creating inefficiency, overwork and thus crazy sweating. Studies also indicate that high amounts of caffeine are sweated out. Furthermore, consuming excessive sugar also manifests itself in unexplained sweating… finally explaining my drippy nose from Tangfastics.

But science geeks have designed remedies. Along with facial deodorant, clinical strength anti-perspirants, and botox (which knocks out acetylcholine transmission in sweaty underarms), Freshmax, the shirt that ‘eliminates sweat patches’ exists. For important meetings or first dates, even without deodorant, it works wonders using ‘smartweave cotton technology.’ Yet solutions have side effects- some treatments merely shift damp patches to ‘other’ areas. Freshmax also only caters for men. Women may be resigned to the knife, with liposuction options quite popular.

Perhaps we must embrace the sweating blessings. It is, after all, a talent of our species- Homo sapiens are the sweatiest animal, and some indigenous tribes view it as sacred. Perspiration reinforces our primal instincts. Scientists discovered a potent sex pheromone, lurking in male sweat, causing electrical activity rushes in the brains of straight women and gay men. These male chemicals are hypothesised to attract sexual partners. But excitement also requires rest. Pennsylvania University discovered that when applying swabs to women’s noses that had been drenched by male armpits, after 6 hours women reported feeling ‘less tense’ and ‘more relaxed’!

Researchers claimed to have found a human alarm pheromone released in the sweat of skydivers, allowing others to subconsciouslydetect stress or fear. Sweat can convey tension, as brain regions associated with fear were stimulated in volunteers who breathed in the ‘fear’ sweat. This detectable scent made people more alert to potential threats, displaying vigilance, even suggesting that stress is contagious.

Sweating, as embarrassing as it seems, has important benefits. Although it appears a conundrum- heavy people sweat more, but also fit athletes sweat more, what hope is there (in terms of sweating) for a heavy person trying to get fit? This worry should be dismissed. Sweating awards you a natural, youthful glow only reflective of a busy, fun lifestyle and active sex-life. It is these animal instincts that we should celebrate, and ignore the 580 calories lost per 1L of sweat. Our body is part of nature, and contains the same salty solution as the sea.

Esther Lie

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