From the minute they arrive at the park, children move constantly. They run, jump, chase, and climb. Wrapped up in their fun, they aren't thinking about the health-promoting effects of exercise. But NIDA scientists are. Staff scientists are considering the possibility that exercise—including active play, outdoor adventure, team sports, martial arts, and dance—not only boosts energy and keeps weight in check but also helps prevent substance abuse. NIDA has already invested over $4.3 million to spur research on this emerging area of addiction science.
Although people tend to think of exercise as good for the body, it also benefits the brain. As it invigorates the heart and lungs, it stimulates the brain's reward pathway and heightens mood-boosting neurochemicals. Animal research indicates that exercise promotes the formation of blood vessels in the brain, forges connections between cells, enhances repair of neural tissue, and generates new neurons in memory-formation areas. Through its actions on hormones that affect the nervous system, exercise also improves an animal's tolerance of stress—an observation that is particularly intriguing given the links between stress and drug abuse.
Such observations may explain why competitive runners experience mood elevations, physical activity sometimes relieves mild depression, and older people who exercise improve in both mood and cognitive function.
Patterns of drug abuse among teens suggest that physical activity can strengthen resistance to addiction. Results from the NIDA-funded Monitoring the Future survey, for example, indicate that high school students who exercise regularly are less likely than sedentary teens to smoke cigarettes or abuse marijuana ("Lower Rates of Cigarette and Marijuana Smoking Among Exercising Teens"). The relationship between drugs and exercise, however, may be indirect. Perhaps students who choose to exercise tend to make healthy decisions in general. Initiation of substance abuse may also be countered by the support of teammates, coaches, and family; by other social aspects of participation in organized activities; and by the time management skills that active teens develop.
Apart from improving the health of the developing brain, there are many reasons to think that physical activity can be a useful means for preventing substance abuse among young people. The best way to grab the attention of children and teens is often to offer them a range of appealing challenges. Physical activities—particularly in natural environments—offer youth healthy opportunities to learn skills, take risks, and achieve goals.
I run 6 miles a day because I enjoy it. But, as a neuroscientist, I'm intrigued that physical activity is good for the brain. At NIDA, we look forward to supporting groundbreaking research on the neurobiological, psychological, and social processes by which exercise may promote overall well-being and protect against drug abuse and addiction.