Hand weights, running, swimming: Just do it. For people prone to high blood pressure, having more muscle than fat helps control blood pressure during stressful times, researchers say.

Blacks — a race especially at risk for stress-related high blood pressure — stand to benefit the most, writes researcher Martha E. Wilson, with the Georgia Prevention Institute at the Medical College of Georgia in Augusta.

Her study appears in the current American Journal of Hypertension.

Earlier studies from the Georgia research group have shown that when body mass index (BMI, an indicator of body fat) is high, the body gets overwhelmed by excess sodium during stressful times, explains Wilson. The result is a spike in blood pressure.

Studies have also indicated that blacks are especially at risk for this blood pressure spike, writes Wilson. Also, males seem to be at even higher risk, she notes.

Wilson and colleagues examined this pattern in 127 young adults. They monitored blood pressure every 15 minutes for five hours — two hours before and after a one-hour video game session.

All of the players’ blood pressure increased about 5 percent during the video game phase, which is considered normal. However, for leaner players, blood pressure returned more quickly to normal — about 25 percent faster than those with more body fat, reports Wilson.

During the study the researchers also tested urine for sodium amount. The body responds to an increase in blood pressure by excreting more sodium in urine. If the body fails to excrete enough sodium, high blood pressure may result.

The researchers found that people with more body fat did, in fact, excrete less sodium in their urine. This finding may explain the link between more body fat and higher blood pressure in response to stress.

Also, blacks in the study had higher levels of blood pressure in the stress portion of the study. This pattern is consistent with other studies, which showed that black people’s blood pressure was slower in recovering to normal levels.

Being overweight and having high blood pressure are leading causes of heart disease, the nation’s No. 1 killer.

By Jeanie Lerche Davis, reviewed by Brunilda Nazario, MD

SOURCE: Wilson, M. American Journal of Hypertension, November 2004, vol.17: pp 1023-1028.