Thrombosis, the abnormal formation of a blood clot in an artery or vein, is a major cause of serious illness and death in Western countries, according to an April 2009 article published in "Seminars in Thrombosis and Hemostasis." The article says there is evidence that physical activity lowers the risk of blood clots in younger people and those with chronic conditions such as cardiovascular disease. However, in older people, exercise is less likely to reduce the risk of blood clot.
Background
Blood is a liquid circulating inside the cardiovascular system. Normally, anti-clot enzymes in blood prevent blood clots except when they are necessary. When there is an injury to blood vessels, blood clots seal off the damaged area and prevent loss of blood. However blood clots that form in the heart, lungs or brain can be a serious threat to your health.
Risk Factors
When blood circulation slows, blood can thicken and clot, even when there is no injury. Blood clots can be caused by a variety of factors, including smoking tobacco, stress, high cholesterol, dehydration, varicose veins, lack of exercise, immobility and pregnancy, according to Dr. Philip Chua of the Cebu Doctor's University. Cancer can also increase your risk of blood clots, and some people have a tendency to clots for no known reason.
Benefits of Exercise
After exercise, blood both clots faster and unclots faster. This reduces the risk of blood loss in an injury and reduces the risk of atherosclerosis, according to Dr. Michael Olpin of Weber State University. Atherosclerosis is a hardening of the arterial wall that contributes to the formation of blood clots. Fit people produce more of a substance called tissue plasminogen activator, which helps dissolve clots. People who don't exercise regularly have less of this substance in their blood vessels and are more prone to blood clots.
Expert Opinion
Although there is conflicting evidence about whether exercise helps prevent blood clots, according to an article published in The Physician and Sports Medicine in 2009, the weight of the evidence suggests that it does help. Exercise seems to help maintain the delicate balance between clot formation and clot dissolution in normal people. If you have never had a blood clot, exercise can help prevent it. If you have had a blood clot, discuss exercise options with your physician to prevent future blood clots.
References
- "The Physician and Sports Medicine"; Exercise Causing Thrombosis; M. Adams et al.; Dec. 2009
- "Seminars in Thrombosis and Hemostasis"; M. Adams et al.; April 2009
- Weber State University: Benefits of Aerobic Conditioning
- CEBU Cardiovascular Center: Pulmonary Embolus
- CEBU Cardiovascular Center: Blood clots
