A study published in the journal, Circulation, August 9, 2010, showed that exercise capacity is inversely related to all-cause mortality in 5314 older men (ages 65-92). The survival benefit was observed among individuals able to participate in moderate physical activity such as brisk walking. The benefits increased with exercise capacity. Those with an exercise capacity of 5 METS (1 MET is a body at rest) had a 38% lower risk of death compared to unfit individuals, and those able to achieve 9 METS or more reduced their risk of death by 61%. Another great thing about this study is that many of the subjects started exercising after the age of 70, and were able to achieve reduced risk almost equal to those who had been fit for a longer period. One can achieve a fitness level of 5 METS or more by 20 to 40 minutes of brisk daily exercise. In other words, some exercise is beneficial, more is better, no matter when you start.
One of my favorite writers is Gretchen Reynolds, who writes about the latest in the science of fitness for the New York Times. Her recent article covered a study suggesting that activity helps control anger and rage. For years, scientists have known that exercise can affect certain moods, and exercise programs have been used to treat clinical depression, addiction, and other afflictions. This is the first study I’ve seen that addresses the question of whether exercise can affect how angry you become in certain situations. It was recently presented at the annual conference of the American College of Sports Medicine. In the study, hundreds of undergraduates at the University of Georgia filled out questionnaires about their moods. From that group, researchers chose 16 young men with “high trait anger” or, as Ms. Reynolds calls it, “a very short fuse.” During the two days of the study, the men were fitted with hairnets containing sensors that could read electrical activity in the brain. Researchers then flashed a series of slides across viewing screens set up in front of each man. The slides, designed to induce anger, depicted upsetting events like Ku Klux Klan rallies and children under fire from soldiers. Electrical activity confirmed the men were getting angry watching the slides; in addition, they described to researchers how angry they felt on a scale from 0 to 9. On alternate days, after viewing the slides again, the men either sat quietly or rode a stationary bike for 30 minutes at a moderate pace while their brain activity was being recorded. Afterward the researchers compared how angry the subjects became during each session.
The results showed that when the volunteers hadn’t exercised, their second viewing of the slides invoked more anger than their first. On the other hand, when the men exercised, their anger reached a plateau. The still got angry, but exercise allowed them to end the session no angrier than when they began it. The study suggest that even a single bout of exercise can have a prophylactic effect against the buildup of anger. In other words, when they exercised, they were able to handle what they saw with more aplomb; their moods were under firmer control.
No one knows how yet, but scientists suspect that serotonin levels played a role. In animal models, low serotonin is associated with aggression, and exercise is known to increase serotonin levels. One more reason to get moving.
Stay well, John R Blilie, M.S.