Exercise: The male-female divide

While we know exercise is good for us, many researchers continue to investigate exactly how it affects our nervous system. One of the moest interesting studies conducted recently includes a look at the patterns between the sexes, which is revealing how differences affect blood flow and oxygen delivery to skeletal muscles.

Led by Emma Hart, Ph.D., a research fellow under Dr. Michael Joyner at the Mayo clinic, the research team’s study reveals a difference in how nerve traffic (nerve pulses per minute) influences the way men and women regulate blood pressureT

The findings may have important implications for understanding how hypertension and other disorders of blood pressure regulation occur in men and women. “We took some young men with variable nerve traffic and showed that people with very high nerve traffic had constricted blood vessels but a lower cardiac output, and that was one of the factors that kept them from having high blood pressure,” says Dr. Joyner. In young women this relationship was absent. “It’s an indication that the women’s blood vessels and cardiovascular systems responded to nerve impulses differently.”

In young women, the team suspects that reproductive hormones, known to be protective against cardiovascular disease, may prevent the blood vessels from becoming constricted when nerve traffic is high.

“We've known for many years that men and women are different in terms of blood pressure regulation,” says Dr. Charkoudian, who is working on the project. “We know that young women have a lower risk of developing hypertension (high blood pressure) compared to young men. In this study, we focused on the importance of the sympathetic nervous system and its control of blood vessels as determinants of long-term blood pressure. Our data suggest that one of the ways women are ‘protected’ is by an influence of female hormones to alter this nerve-blood vessel interaction.”

The Joyner lab recruits a wide range of people for their studies including the occasional elite or master athlete, active and sedentary people, and those with medical conditions such as hypertension, heart failure, diseases of the autonomic nervous system and, especially people who have problems with blood pressure regulation.