Sweat happens. Throughout every day of your life, you exude a watery blend of urea, salts, sugars and ammonia from your pores. Most people presume that when you sweat, you lose weight. It's true that when you sweat, you shed some weight. However, most of the weight you lose is water weight, and you regain that as soon as you rehydrate. Any real weight loss that occurs when you sweat happens because of what you are doing that makes you sweat, and not because of the sweating.
结构和功能
在2到400万汗腺之间，埋在皮肤下层，不断分泌水和电解于皮肤表面。双手的手掌和脚底的鞋子密集有汗腺，含有多达3,000个每平方英寸的腺体。您的生殖器区域和腋窝也具有高密度的汗腺。经过各种身体的经过滋生汗腺，有助于调节体温。当您的内部温度升起时，您的经过鱼腺释放水到皮肤表面，通过蒸发冷却皮肤。Apocrine汗腺，通常位于位于手臂下方的毛囊附近，以及在您的生殖器区域以及其他几个区域，不断释放脂肪汗水。Apocrine汗腺没有已知功能。他们似乎是性气味腺体的遗传残余，报道了Sweating.ca网站。Apocrine汗腺被情绪压力引发。
Causes
You sweat when your brain tells you to sweat. The hypothalamus, a tiny structure in your midbrain, collects information about your body's temperature from nerves in your skin and from other parts of your body. When your body temperature rises, your hypothalamus sends a message through your sympathetic nervous system to your sweat glands. A variety of situations can trigger your hypothalamus to turn your sweat glands on. A warm climate, exercise, humidity and spicy food cause your body to heat up, which triggers sweat.
下丘脑还规定了对压力和情绪唤醒的反应。当您认为存在某种威胁时，您的下丘脑会发出肾上腺和垂体腺来释放应激激素。这些激素增加了你的情绪和生理唤起，导致通常被称为“战斗或飞行”的反应。这是一种预期唤醒的状态，准备你的努力。由于这是一种广义反应，因此由影响身体所有部位的激素调节，因此您在您拥有最多汗腺的位置产生最大的汗流：您的头皮，手，脚和腋下。
汗水减肥损失
People differ in how much they sweat, but on average, people lose 1 to 1.5 pounds of water by sweating each day. If you live in a hotter climate, exercise more or have a less efficient thermoregulatory thermostat, you might lose more weight through perspiration. Stew Smith reports at Military.com that during three to four hours of ocean swimming, most of his Navy seal class lost 10 to 15 pounds by sweating. Weight lost through sweating is mostly water weight. Urea, salts, sugars and ammonia -- waste byproducts of nitrogen metabolism -- contribute a negligible amount of weight to your loss.
Temporary Weight Loss
Athletes who want to qualify for a certain weight class induce sweating to accelerate temporary weight loss. Some wear sweatsuits or garbage bags, or sit for hours in a sauna to drop pounds. In a 2008 article posted on the website eliteFTS.com, power lifter Matt Kroczaleski describes a protocol he uses to temporarily drop as much as 15 percent of his body weight. Few medical practitioners would recommend Kroczaleski's approach, as it places stress on the body and creates health risks. If you are interested in true, long-term weight loss, do cardio to burn calories, and count on your sweat to cool you off, but not slim you down.