Exercise and training effects on platelets in health and disease.

In recent years the involvement of platelets dysfunction in atherogenesis and in the clinical complications from atherosclerosis has become more recognised. Systemic platelet-related thrombogenic factors have been shown to be involved in the initiation and progression of atherogenesis and plaque growth. Over the last two decades, interest has been heightened regarding the changes in platelet aggregation and functions that are associated with exercise in normal subjects and also patients, particularly those suffering from coronary artery disease. Although exercise effects on platelet aggregation and function in healthy individuals have been examined, the results reported have been conflicting, most likely due to methodological problems in the measurements of platelet aggregation and activation during and after exercise. However for patients suffering from coronary heart disease, the balance of evidence available would strongly suggest that platelet aggregation and function are increased with exercise. Several drugs are known to affect platelets, the most studied among them is aspirin. The evidence available would suggest that aspirin is ineffective in attenuating enhanced platelet aggregation and activation induced by exercise. Although the effects of physical training have been briefly investigated, available meagre evidence suggests that exercise on a regular basis is associated with favourable effects on platelets aggregation and activation in both men and women.