Adiponectin responses to continuous and progressively intense intermittent exercise

Purpose: Adiponectin is a recently discovered adipocyte protein that is lower in patients with coronary artery disease and in Type 11 diabetics who have insulin resistance. Regular exercise is known to be a preventative factor in the development of atherosclerosis and Type 11 diabetes. Acute exercise increases insulin sensitivity; however, it also increases beta-adrenergic and glucocorticoid activities that may suppress adiponectin expression. Two experiments were conducted to determine whether acute exercise affects adiponectin concentrations. Methods: In the first experiment, six healthy male subjects completed 30 min of heavy continuous running exercise at 79% of VO2max. In the second experiment, well-trained runners completed strenuous intermittent exercise consisting of treadmill running at 60, 75, 90, and 100% VO2max. A resting control trial for the second experiment was also conducted. Results: Glucose and insulin were not altered significantly in the first experiment, but both increased significantly (P < 0.05) in the second experiment. A significant increase (P < 0.05) in adiponectin in the first experiment was no longer significant after correction for plasma volumes shifts. In the second experiment, there were significant (P < 0.05) changes in adiponectin concentrations over time but not a significant difference between adiponectin responses in exercise and control trials. Conclusions: The data suggest that 30 min of heavy continuous running or more strenuous intermittent running does not stimulate an increase in production and release of adiponectin, and small increases in adiponectin concentrations resulting from the exercise may be attributed to normal plasma volume shifts.