Four Days in Gym May Be Better than Six! Just Sayin'

Feeling guilty about not hitting the gym every day? Maybe you shouldn’t, new research suggests.  The New York Times reports on a new study.

Working out four days a week may be at least as beneficial — or even better — than six, according to a new study by sports scientists at the University of Alabama at Birmingham. What’s more, working out as little as a couple times a week can provide substantial health benefits.

The UAB study, published in the journal Exercise & Science in Sports & Medicine, tracked 72 sedentary women — aged 60 to 74 years — who were divided into three groups and asked to follow different exercise regimens for a 16-week period.

The first group exercised twice a week, lifting weights one day and doing aerobic exercises (bike riding or jogging) on another. The second group engaged in four workouts a week, lifting weights twice and riding a bike or jogging on two other days. The third group exercised six days a week, lifting weights three days and doing aerobic workouts on three others.

For each group, researchers gradually increased the intensity of the workout routines to moderate levels to build endurance and muscle strength. By the end of the study, the workouts were 40 minutes long on each exercise day.

The results showed that all of the women lost weight and improved their strength and endurance. In addition, the researchers noted there was virtually no difference in fitness or strength levels among the groups, regardless of whether they exercised two, four, or six times a week.

But the results also indicated that, after four months, the women exercising four times per week were expending far more energy on workout days — by more than 200 additional calories — than they were at the start of the study. They were also burning more calories per workout than either of the other two groups.

The twice-a-week group was expending slightly more energy on each workout day — about an additional 68 calories — than at the start of the study. But, unexpectedly, the six-times-a-week exercisers were actually burning less daily energy — about 150 fewer calories — than at the start of the study. They also complained that the workouts took too much time out of their weeks, and made them less likely to be active when they weren’t formally exercising.

But even the six-day exercisers were not overly fatigued. The researchers also found that their blood levels of stress-related cytokines, believed to measure nervous system changes that may signal stress in the body, were not any higher than women in the other two groups.

The findings contrast with some past studies that have suggested working out only a couple times a week isn’t enough to be beneficial, boost fitness, or lose weight. They also differ from previous research that has indicated vigorous daily exercise may be too physically taxing and can cause problems with the central nervous system and increase stress in the body.

In fact, the UAB team’s findings suggest even two workouts a week can produce substantial benefits and that people who have time and like to exercise almost every day don’t suffer ill effects.

“All groups increased fat-free mass, strength, and aerobic fitness, and decreased fat mass,” the researchers concluded. “No changes were observed in cytokines or perceptions of fatigue/depression.”