We’ve heard the maxim again and again: Find a type of exercise you enjoy and stick with it. A new study proves that today’s workout is crucial for our health – and our figures – over time.

Published in the journal of Medicine & Science In Sports & Exercise, the study looked at the diet and exercise habits of Americans ages 20- to over 70-years-old.  Researchers determined that whether or not a person engaged in “moderate to vigorous” physical activity was the most likely predictor of their ability to avoid the inevitable age-associated weight gain. The study was calculated through measurements on activity as well as weight, body mass index, waist circumference and quality of diet. The researchers also controlled for factors like race, ethnicity, socioeconomic status and whether or not a person smoked..

READ MORE: Being Inactive Is More Unhealthy Than Being Obese

Researchers noted our physical activity tends to decrease as we age. As lead researcher Russell Pate, Ph.D., of the University of South Carolina, put it:

“Our study points to the very important impact of physical activity on weight status in U.S. adults, and in particular it points to the critical role of the age-related decline in physical activity on the increasing rates of overweight and obesity that we see with aging.”

Interestingly, even though aging adults may not be working out, they are still willing to change their diet. However, the change hasn’t been helping much: “Our findings indicate that increasing fatness with age in U.S. adults cannot be explained by changes in the quality of the diet they consume,” says Pate. It turns out that Americans are more likely to switch to lean protein and salads once they notice some weight gain, as Huffington Post reports. Unfortunately, as we age, those nutritional changes don’t have the same effect on weight as plain old exercise does.

Pate recommends Americans get 150 minutes of “moderate intensity physical activity per week,” or thirty minutes five times a week. That means Americans of all ages!

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