„I’m not out there sweating for three hours every day just to find out what it feels like to sweat“ – Michael Jordan

garnett sweatI am a big fan of sports quotes and slogans: the bigger they sound the better. This simple quote by Michael Jordan is one of my favourites and knowing Michael Jordan’s career and background makes these words sound even more appropriate. Surprisingly, the word „sweat“ is quite often used in these motivational sayings when talking about reaching limits and achievements through hard work. It is popular not only in the sports context: politicians, actors and writers also like to mention this particular body fluid. But if Michael himself brings up the topic, well, then lets talk about sweat!

„Sweat makes the green grass grow“

It is clear that sweating goes hand in hand with practice as much as white clothing does with Wimbledon. Among recreational athletes, sweat is often used as an indicator of the quality of the practice (the training has been successful when you drown  in it). Others say that sweating helps to get rid of toxins. Despite these facts, sweat has only one purpose – to balance body temperature via evaporation; more precisely – to cool down the body when the temperature gets too high. When the body temperature starts to rise during exercise, certain responses follow. The heart has to beat faster to provide increased blood flow, and capillaries under the skin dilate because this is usually cooler than body temperature. If these mechanisms are not enough to cool down the body, sweating occurs. There are approximately 2-4 million sweat glands in the human body which are located all over the surface of the human skin. Sweat consists of 99% water, the remaining 1% is made up of sodium, potassium, calcium, magnesium, long chain fatty molecules and urinic traces. It is also interesting to know that sweat itself has no odor, a stench is released when sweat reaches the skin and mixes with the normal bacteria there.

„No one has ever drowned in sweat” – Lou Holtz

Sweating is very individual. An average person sweats between 0,8 to 1,4 litres per hour (L/h) during exercise. Long-distance runners have been shown to sweat around 0,54-1,83 L/h, cyclists 0,29-1,25 L/h, basketball players 0,7-1,6 L/h and soccer players 0,7-2,10 L/h. It is obvious that results are very different between sports as well as individuals. The highest recorded sweat rate for an athlete in an exercise situation is 3,7 L/h, recorded by a marathon runner Alberto Salazar, while preparing for the 1984 Summer Olympics.

An intriguing question for many people is – do swimmers sweat? Even though it is more difficult to detect it (as the athlete is immersed in water), swimmers, of course, do sweat. In hot, humid conditions, swimmers have been found to lose around 0,6 litres of sweat during 1 hour of training (on average distance of 4 km). Another study proved that training in water causes different sweating adaptations. Differences in the sweat rates between runners, nonathletes and swimmers were measured while cycling at similar intensity for 30 minutes. The sweat volume of swimmers was lower than that of runners and similar to that of nonathletes. Sodium content in sweat of swimmers and nonathletes were significantly higher than those of runners.

„My blood, my sweat, your tears“

Besides the particular sport, sweating depends on many factors, such as an environment (temperature, humidity level), intensity of exercise, stress level, anxiety, digestion, breathing, clothing, genetics, fitness level, acclimatization, body size and gender. It has even been measured that the presence of head hair results in a lower sweat rate compared to baldness.

„Men sweat and women glow“

True, gender plays big role in sweating – men tend to sweat faster than women and have a higher sweat loss  which can be even up to 40% more than women. In addition, women tend to regulate the amount of water they lose better. Even though there is no difference in the amount of sweat glands, larger surface are in men and hormonal variations play a big role.

„I trade sweat for strength. I trade doubt for belief ..“

In addition to above mentioned differences, exercise level also seems to play an important role in sweating rates. Myths about amateurs and unfit persons sweating more are far from the truth – trained people sweat more and faster than less trained. This occurs for very obvious reasons – athletes’ bodies are running in optimal mode, their bodies adapt to stressful stituations by increasing the amount they sweat. On the contrary, unfit people need to bring their body temperature significantly higher to start sweating at maximum capacity.

 „Sweat is fat crying“

Some exercisers may think that sweating helps to burn fat. As mentioned above, there is a tiny proportion of long-chained fat molecules in sweat but this is not related to fat- or calorie-loss at all – 99% of the time we are simply losing water. Even though it is obvious that by heavy exercise, many calories are lost, sweating alone does not directly influence this outcome.

Water loss, however, adversely affects our performance. Dehydration immediately impairs temperature regulation and leads to defects in performance, affecting alertness, muscular strength and endurance. It also causes stress on cardiovascular function. That is why it is important deal with the consequences of sweating by simply compensating for water loss with adequite fluid replacement.

 „The more I sweat in practice, the less I bleed in battle“

Even though athletes are not doing hard work just to lose water, sweaty towels and gym floors are part and parcel of training and sports. I have not seen a single athlete who is embarrassed of their sweating or complaining about it. Sweat will remain an active marker of sports dedication even if it is just water that is released for basic physiological reasons.

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