Sickle cell disease is an inherited blood disorder that causes an alteration in the shape of red blood cells, causing the cells to destruct, resulting in anemia and reducing the amount of oxygen available in the blood. Most people with the trait do not exhibit any problems during physical activity, but because of the potential risk involved, patients, physicians and sports coaches should be aware of the needs of these patients during exercise.
Identification
Sickle cell trait condition, or the presence of at least one abnormal gene involved in the production of hemoglobin, the portion of the red blood cell that carries oxygen to body tissue, is considered a benign condition that does not affect lifespan. About 8 percent to 10 percent of the black population in the United States has the trait, but about 1 percent has sickle cell anemia disease, in which two abnormal genes are present. In this case, the number of blood cells is fewer and oxygen delivery is reduced, making exercise more difficult.
Benefits of Exercise in Sickle Cell Patients
Physical activity is essential for overall good health, particularly in reducing the risk of cardiovascular disease. Stroke, for example, is a leading cause of death among sickle cell patients, especially children. Low-impact exercise is particularly useful for maintaining strength. Experts from the National Heart, Lung, and Blood Institute recommend that sickle cell patients work with their physicians to find an exercise that is appropriate.
Sickle Cell Trait and Intense Physical Activity
During intense physical activity, red blood cells can change from their normal round shape into something resembling a crescent moon or "sickle." These abnormally shaped cells can accumulate inside the blood vessels, causing a blockage of the normal flow of blood and oxygen to body tissues. Certain conditions, such as heat, dehydration and altitude, can increase the risk of this occurring.
Risk of Unexpected Exercise-Related Death
One important consideration for those with sickle cell disease is the increased risk of unexpected exercise-related death, or ERD. This risk was originally discovered by scientists studying the deaths of four U.S. Armed Forces recruits during basic training at Fort Bliss. All four were found to have sickle cell trait and the most common causes of death were "exertional rhabdomyolysis" (the breakdown of skeletal muscle) and cardiopulmonary arrest due to high potassium levels. There have not been studies conducted in athletes, so currently the American College of Sports Medicine and the National Collegiate Athletic Association place no restrictions on the participation of sports in those with sickle cell trait.
Staying Safe While Exercising
The NCAA offers tips for preventing a sickle cell-related crisis during exercise. It recommends building intensity slowly and incorporating adequate rest periods between repetitions. Stay well-hydrated and avoid extreme exercise during hot and humid conditions, and monitor closely for symptoms such as muscle pain, abnormal weakness or unusual fatigue. If these occur, stop the activity immediately and seek immediate medical care.
