Many bio-mechanical and chemical changes occur in the body as a result of exercise. We are going to look at some of the hormones involved as a result of weight training.
Testosterone is released as a result of weight training; and regular weight training will increase the long-term production of testosterone levels. Don't worry ladies: weight training won't turn you into a man. In fact you already have testosterone running through your veins right now! The increased testosterone release will increase your strength, energy and focus levels and also your ability to burn fat. The higher the intensity and the more muscles involved with the specific exercise, the greater the testosterone-boosting effect will be. For example, squats and deadlifts will release more testosterone than bicep curls or calf raises.
2. Human growth hormone
Growth hormone (for short) is another hormone released during exercise that has a great host of benefits. This hormone helps to regulate sleep, increase the rate at which your body can recover (from exercise and illness) and even helps to burn fat. Just like testosterone above, more growth hormone is released with compound weight exercises (exercises that involve more than one muscle group).
3. Increases insulin sensitivity
Your body stores energy in your muscles in the form of glycogen. When you do weight training, you use up the glycogen stores in your muscles. These glycogen stores are converted to sugars for the energy needed for muscles to constrict and release. After exercise, your body starts to replenish these glycogen stores by taking glycogen out of your bloodstream and re-storing them in your muscles. This action increases your insulin sensitivity and is one of the reasons why exercise combats diseases like diabetes.
Cortisol is one of your stress hormones. When you are stressed at work, for example, your body releases cortisol as a response. This hormone is supposed to prepare your body for the physical work that it needs to do to get out of what your body perceives as a dangerous situation. Exercise (both aerobic and anaerobic) provides great stress relief because of the way it works with cortisol. By doing something physical, your body feels like the stressful situation has now been avoided and cortisol levels can decrease. If you don't exercise, these cortisol levels can accumulate and wreak havoc in your body because your body is constantly preparing for some type of physical action because of the cortisol release but never ends up doing the physical activity needed to release the cortisol. Also, highly intense or a prolonged duration of exercise can stimulate the release of cortisol. This is not a good thing if your main goal is muscle growth, because cortisol is catabolic. When your body is in a catabolic state, it will break down muscle for short-term energy as a survival mechanism. In order to stay in an anabolic state (the state your body needs to be in to build muscle), don't exercise for too long and get muscle-building nutrients into your body as soon as you can. This assures the body that the perceived danger is over and that it can start rebuilding in preparation for the next challenge. Most people recommend keeping workout times at a maximum of 90 minutes, but I simply increase rest times in between sets to curb cortisol release.
Endorphins are known as the happy hormones. They are released as a bodily response to pain. This is what makes eating chilies or getting tattoos addictive: the endorphins released as a response to the pain can be addictive. Your body releases these hormones to soften your pain and help you stay on top of things. In survival, this would be important in making sure that you still have the will to fight or live after being in a physically challenging situation. Endorphin release can be addictive and the mental 'high' you get after working out is what many people look forward to, including me. I love the feeling that I am on top of the world and that I have really succeeded in getting further in life when walking out of the gym. This is also why some people struggle to take enough rest days. I have sometimes experienced withdrawal, or 'sad' feelings, when I am a few into a vacation, because my brain is not getting its regular endorphin fix that it so patiently looks forward to. This is also a great motivation for people just getting into exercise. I always tell people that if you stick with exercise long enough, you will actually start enjoying it and looking forward to it. First you hate exercise, then it's not that bad, then it's just something you do every day, then it becomes something you look forward to and finally it becomes something you don't want to live without. The secret is sticking it out until you get to the last stages. Endorphin release from exercise makes it a great method of addiction recovery. Studies have shown that exercise increased success rates in people fighting addiction, because they are mentally forced to focus on something else and the endorphin release gives them a sense of relief and a small piece of the 'high' they have been craving.
Looking at the relationship with hormones and exercise just gives us more reasons why exercise is so great for you. STAY STRONG!