Climate’s effect on exercise

A sunny, balmy day might seem like the perfect opportunity to exercise. But, apparently, not if it’s also humid. A new study shows that people who live in hot, humid areas get much less exercise than people in cool, dry areas.

In a comparison of residents of 49 states, the District of Columbia and Puerto Rico, the last group was found to be the least active, with only 30.9% of Puerto Ricans getting the recommended amount of exercise each week. Topping the list of physically active areas was Montana, where 60.9% of the generally cool and dry state’s population met recommended levels of physical activity.

“The correlation was even more strong than I thought it would be, given today’s many alternatives to working out outside,” said study author Ray Merrill, a professor of health sciences at Brigham Young University.

Using physical activity data from a Centers for Disease Control and Prevention survey of U.S. states and territories, researchers compared the results with information from 255 weather stations across the nation. The stations measured temperature, dew point temperature, wind, air pressure and cloud cover.

They found that the hottest and most humid areas had the lowest levels of physical activity. The driest, most moderate areas had the highest levels of physical activity.

After Puerto Rico, the states with the lowest levels of physical activity were Hawaii, where only 36.4% of people got the recommended amount of exercise, and North Carolina with 37.4%. On the high end of the range were Utah, 59.2%, and Wisconsin, 57.9%.

California was in the middle of the range, with 49.2% meeting recommended levels of activity. (Alaska wasn’t included in the survey.)

The CDC recommends 30 minutes of moderate activity five or more days of the week, or 20 minutes of vigorous exercise three or more days per week.

The study was published in the American Journal of Health Behavior.