Exercise increases the number and function of energy-making factories in muscle cells, which protects against development of type 2 diabetes, says a researcher.
Diabetes specialist Nicolas Musi, M.D., associate professor in the School of Medicine at The University of Texas Health Science Center at San Antonio, said that whether a person is 8 years old or 88, exercise helps protect against type 2 diabetes.
It does this, in part, by revving up the function of small structures called mitochondria, which are found inside cells.
Musi studied the effects of exercise on 100 muscle biopsy specimens and is documenting how exercise affects the mitochondria. Mitochondria function as "energy factories" by taking up different nutrients and converting them into energy.
"With age, there is a decline in the number and function of the mitochondria. We did an exercise intervention in older individuals and noticed that physical activity improves mitochondrial function substantially in people over 65," Musi said.
"While the benefits are related to the amount of exercise, in general, any amount of exercise is better than none.
"Even small amounts of exercise can confer benefits. However, it is important to design an exercise program that will notcause harm, particularly in older persons or those compromised by conditions such as heart disease. If an older person has not done regular exercise for several years, it is best to begin a new exercise program under the supervision of a physician or certified trainer," Musi added.
Age-related decline in the number of mitochondria contributes to type 2 diabetes, but exercise can reverse it.
"Older patients have a high incidence of diabetes and pre-diabetes, but respond very well to exercise. We are investigating how physical activity can prevent diabetes in people who have pre-diabetes," Musi said.
Musi said that with exercise, the muscle becomes more efficient at burning sugars and fats.
Scientists don’t know why, but one hypothesis is that exercise activates an enzyme called AMP kinase. This enzyme monitors energy levels and maintains normal levels of energy in cells.