Even a Little Exercise Fights Obesity

Nov. 6, 2009 -- While frequent exercise is known to fight obesity and improve mental health, as little as 30 minutes of physical activity one or two days a week can have benefits, according to the 2009 Gallup-Healthways Well-Being Index.

The Well-Being Index is based on nearly 288,000 phone interviews of people 18 and older. It shows the number of days a person exercises for at least 30 minutes is strongly connected with the likelihood of obesity:

• Not exercising in a given week was associated with a 35% incidence of obesity. 
• Exercising for 30 minutes, 1-2 days a week, was associated with a 28% incidence of obesity 

However, the survey also showed that those who exercised every day were slightly more likely to be obese (20%) than those who say they exercised five or six days (19%).

Gallup-Healthways analyst Brett W. Pelham, author of the 2009 report, tells WebMD in an email that "exercising several days a week seems about as good, and arguably is better, than exercising every day, especially when you consider return on investment."

The survey also looked at the connection between the number of days of exercise and quality of life; it included questions to determine if people felt they were struggling, suffering, or thriving in life. As little as a half-hour daily of exercise for one or two days seemed to help their self-perceptions.

People who exercised more frequently had a higher payoff in their evaluation-of-life response, according to the report. Once again, there was a substantial drop for those who exercised every day.

According to the Gallup survey report, the data cannot tell us whether exercise leads to high well-being or whether high well-being leads to exercise, but they do suggest that getting the maximum amount of exercise may not promote further gains in well-being.

Exercise and Emotional Health

The Gallup-Healthways Well-Being Index also contains a measure of emotional health, based on 10 daily experiences, such as smiling or laughing a lot or being treated with respect the day before they were interviewed.

Those who didn't exercise at all earned a score of 74, compared to higher scores  for those who worked out one or two days per week or more. Yet, for those who report having exercised every day, the survey showed slightly lower Emotional Health Index scores than those who say they exercised five to six days. Again, the score dropped for people who said they exercised seven days a week.

The Gallup-Healthways Well-Being Index also examined depression and found it too was related to exercise. People who report not having exercised in the past week are almost twice as likely to have been diagnosed with depression as those who claim to have exercised five to six days, the report says.