Stay on the path: Exercise helps whether your weight is going up or down.

RODALE NEWS, EMMAUS, PA—There’s nothing more maddening than regaining the precious pounds you lost during what you thought was a successful weight-loss program. But all is not lost even if you lose and then regain weight. Far from it. A University of Missouri study found that most of the health benefits you gained when you lost that weight likely remain intact, as long as you keep getting regular exercise. Other studies have clearly shown that a weight-loss program that includes exercise is more likely to be successful—and permanent—in the first place. So it's clear that exercise is your friend whether you're shedding pounds or on a diet rebound.

THE DETAILS: Missouri researchers placed 67 overweight or obese people on reduced-calorie-plus-exercise regimens for four to six months until they lost an average of 10 percent of their body weight. At which point the researchers added healthy foods to the subjects’ diets until the extra calories caused everyone to regain 50 percent of the weight they had lost (cruel, yes, but all in the name of science). Half of the group continued to exercise on a treadmill or stationary bike during the “regain” phase, while the other half did no exercise. This second phase also lasted four to six months.

Researchers took blood tests and vital signs at three separate points during the study: before weight loss, after weight loss, and after weight regain. After weight loss, the subjects experienced significant improvements in several key health parameters: blood pressure, LDL and HDL cholesterol levels, triglycerides, blood glucose control (a marker for type 2 diabetes), abdominal fat level, and inflammation markers. The exercising group maintained a healthy majority of these gains (including better blood pressure and blood glucose levels) even after regaining the weight, whereas the non-exercisers saw all their gains diminish significantly.

Read on for tips on keeping those pounds from coming back.