By Rachel Bachman, Wall Street Journal

Mary The Trieu does hourlong workouts at a CrossFit gym three to five days a week. She is also 5-foot-3 and weighs 205 pounds.

Trieu avoids junk food and eats balanced meals, but she’s not on a diet. She works out to keep her weight stable and because she enjoys it.

“As I started exercising, I just got this adrenaline rush,” says Trieu, an admissions officer at Columbia Business School. “It feels good to sweat. And it’s hard. Part of it is my ego: ‘Yes! I’m a bigger person, but I can still do the exercises you’re doing.’ ”

A recent study underscores that there are significant health benefits to overweight and obese people being physically active, even if they don’t lose a pound. The study, of 334,000 Europeans over 12 years, recorded twice as many deaths due to a lack of physical activity as due to obesity.