Benefits of Exercise
Exercise can help to help prevent Diabetes 2 and cardiovascular disease. The major causes of the epidemic of obesity and diabetes in all affluent countries are the wrong diet and a low level of physical activity. High blood sugar levels can be reduced by exercise and over time exercise and proper diet can prevent the consequences of diabetes.
Paffenberger reported that of 50,000 former students at Harvard and the University of Pennsylvania, physical activity reduced the risk of both type II diabetes and coronary heart disease and results in extended longevity. Ruderman praised the remarkable ability of exercise to help prevent type II diabetes and cardiovascular disease. He stressed that research shows that a sedentary lifestyle is a major cause of diabetes 2 and coronary heart disease. Exercise improves insulin action, lowers blood pressure and corrects blood fat lipid abnormalities. The insulin resistance syndrome can be corrected by low intensity, prolonged exercise. The risk of type II diabetes is reduced by 25% and of heart disease by 50% among people who are moderately active.
Kannel described a theoretical chain of events leading to atherosclerosis: abdominal obesity promotes insulin resistance and the pancreas increases insulin production which results in raised triglyceride levels and reduced HDL cholesterol (the so-called "good" cholesterol). This combination of lipid abnormalities is often associated with small, dense particles of LDL (the "bad" cholesterol), which is atherogenic. Insulin resistance leads to glucose intolerance and diabetes, which further promote atherogenesis.
Insulin resistance increases re-absorption of sodium by the kidney, increasing blood volume and producing hypertension, which also contributes to blood vessel disease. Insulin resistance is caused by fat stored in the abdomen. Hip or thigh fat is not associated with major health problems.
Men over age 40 tend to excess abdominal fat and insulin resistance. Women are at greater risk of accumulating visceral fat after menopause. Visceral obesity is associated with elevations of a lipoprotein, apo-B. The combination of high insulin levels and high apo-B, causes an eleven-fold increased risk of heart disease.
This discussion of exercise is discussed in some detail in in the
Book of Diabetes 2.