Effects of exercise on free serum cholesterol.

Two age groups (young and old, n = 12) matched for physical fitness and two physical fitness groups (high and old, n = 12) matched for age participated in a four month physical fitness programme. Blood samples were drawn at four stages of metabolic stress at the pre-test and five stages at the post-test. The blood samples were analyzed by colorimetric methods for total cholesterol and free cholesterol. Statistical analysis revealed that: (1) Short-term exercise increased total cholesterol, free cholesterol, and the percent free cholesterol from the resting state to the submaximal and maximal exercise states. (2) There was no change in free serum cholesterol from the pre- to post-tests. (3) The high-fit group, compared with the low-fit group, had a lower free cholesterol level but had similar percent free cholesterol values. (4) There was no significant difference between age groups for either total serum cholesterol, free cholesterol, or the percent free cholesterol levels.