When we exercise, several physiological processes occur. For instance, blood has to be delivered to different working muscles by the cardiovascular system. When we breathe and respire, air comes into the nose and mouth heading toward the lungs where blood is filled with oxygen. Carbon dioxide, a product of metabolism, then also expires, the list can go on.
The human body is a truly magnificent creation. The same body we have can be trained to lift heavy weights or run long distances. I say “or” as it is a very rare occurrence that one individual can lift heavy weights and run long distances. The body has to choose which stimulus to adapt to. These adaptations are often mediated in our body through hormones, which are chemical messengers produced by the body that regulate the action of different tissues.
Hormones in exercise can either be anabolic, which means to build up, or catabolic, to break down. Here are some hormones that are involved in exercise and physical activity:
Perhaps, the most infamous hormone. Its role in the body is to promote carbohydrate metabolism. When blood sugar levels rise, insulin is secreted to help the body absorb glucose and store it into glycogen. When glycogen levels are full, the excess blood sugar might be stored as fat. Since insulin is a “storing” hormone. Its activity becomes suppressed when we start doing any physical activity.
Glucagon is released when we have a low state of blood glucose. It is produced in the pancreas (the same region that produces insulin) to stimulate the release of fat and increase blood glucose levels. As glycogen becomes depleted during exercise, this hormone releases additional glycogen stored in the liver. In actuality, glucagon and insulin work together to help the body in the storage and release of energy. Glucagon levels rise when we start doing physical activity and is actually one of the reasons why it’s important to perform a warm-up prior to exercise.
Cortisol gains notoriety as the “stress hormone.” However, this hormone also serves a purpose in exercise. As one enters into prolonged exercise, cortisol is a hormone released to break down fat and protein and convert it into fuel. This hormone is necessary for those performing long endurance exercise.
Before you think of exercise as just a physical activity that helps you sweat, try and appreciate everything that is going on inside your body to help you move. In Part 2, I will discuss the other hormones that help one gain muscle mass. The hormones discussed in this article are the hormones that facilitate the use of fuel in the body.