´╗┐ Insulin | Fitness Science Fitness Science

Insulin

Insulin is an anabolic hormone which is responsible for transporting excess glucose from the blood into the cells. In healthy person’s blood glucose will rise after a meal rich in carbohydrates. When the blood glucose is high enough, insulin will be secreted from the pancreas’ beta-cells which will transport the glucose to other storage sites, such as the glycogen stores in the muscles or liver, or when those are filled, the fat cells in adipose tissue. It stimulates protein transport into body cells and therefore stimulates muscle hypertrophy. And in addition insulin inhibits the usage of fatty acids to generate energy as well, so the body temporarily depends more on glucose metabolism.

When the body does not react to insulin as it should, glucose regulation is disturbed. A condition more commonly known as diabetes mellitus type 2. Diabetes mellitus type 2 is characterized by a decreased ability of the body to react to insulin. As a result the pancreas will produce more insulin to store excess glucose into the cells. When insulin production can’t keep up to the rising demand, blood glucose levels will increase too much and don’t decrease quickly enough, resulting in damage to small blood vessels which increases the risk of complications such as heart failure, damage to the kidneys, nerve endings in hands and feet and damage to the retina resulting in vision loss.

In diabetes mellitus type 2 the cells of the body have become less sensitive to insulin and consequently blood glucose levels become unregulated. The decreased insulin sensitivity can have multiple causes, but it decreases due to inflammatory processes associated with being overweight or obese, and being inactive. Insulin sensitivity can be enhanced through higher intensity cardiovascular exercise and resistance exercise. These types of exercise stimulate glucose metabolism and require the muscles to be replenished with glucose and therefore increase insulin sensitivity. Although DM2 cannot be cured completely at present, a healthy lifestyle is an effective means of decreasing symptoms and medicine use.

References:

-Guyton, A.C., Hall, J.E. (2000). Insulin, Glucagon and Diabetes Mellitus. Medical Physiology. Tenth Edition. Philadelphia, USA. W.B. Saunders Company.