Sweating can be caused by a variety of factors, including spicy foods, nervousness and illness, but exercise is arguably the most common. Sweating occurs as a result of movement stimulated deep within your cells in the case of exercise.
Your muscles work harder as you increase your speed, increasing their energy demand. The process of cellular respiration utilises glucose and oxygen to produce ATP, the cell’s energy currency. The mitochondria are responsible for a large part of this process. The more you move, the harder mitochondria work to provide energy to your body. The cells release heat when they break down the ATP. Temperature sensors all over your body are stimulated by the heat. These receptors detect excess heat created by your muscle cells and send the information to the hypothalamus, which controls body temperature. The hypothalamus responds by delivering messages to the sweat glands in your skin via the sympathetic nervous system. These are found throughout the body, with particularly large concentrations in the palms of your hands, the soles of your feet and the top of your head.
In the coiled base of the sweat gland, there is fluid that surrounds the cells which contains high amounts of sodium and chloride. When cells in a sweat gland receive a signal, they pump these ions into a hollow tube that runs through the gland. Water moves into the tube via osmosis because the inside of the tube is saltier than the outside. Water pressure drives the primary secretion up into the long straight segment of the duct as it builds up at the bottom. The cells lining the tube will reclaim as much salt as possible before it leaks onto the skin, allowing the process to continue.
Sweat contains water, which absorbs your body’s heat energy and then evaporates when it reaches the surface, lowering your temperature. This method of cooling, known as evaporative cooling, was a crucial adaptation for our ancestors. This cooling effect is beneficial in a variety of situations, not only during exercise.
Some people’s faces sweat heavily after eating very spicy cuisine. Spices induce the same neurological response in the brain that activates temperature receptors, which are normally activated in reaction to increased heat.
Sweating is also a part of the fight or flight reaction, which is triggered by stressful situations such as asking someone out on a date or going on a job interview. This occurs because adrenaline increases muscle activity and causes blood vessels to dilate, both of which increase heat and produce perspiration.
Sweating might also happen when we are ill. When we have a fever, we sweat because the hypothalamus is stimulated to enhance muscle activity, which releases more energy as heat. This raises your body’s general temperature, a defense response that makes your body less inviting to pathogenic organisms. Sweating allows your body to release heat. When your fever goes away, your temperature receptors detect a reduction in heat, and the hypothalamus stops sweating.
The hypothalamus can also communicate to your body that you need to restore the water you have lost, such as after a run. As a result, when you are pushing yourself to achieve your next goal, think of sweat as your body’s own calibrator, allowing you to go the extra mile.
