Exercise is good for the heart even when it doesn't seem to be doing anything for the waistline. The reverse is also true: losing weight can help the heart even when it isn't getting the daily activity it needs, says the July 2012 issue of the Harvard Health Letter.

Many people equate exercise with weight loss. If they start exercising and the scale doesn't show an improvement right away, they tend to quit. Knowing that their workouts are good for the heart even if the extra pounds are stubbornly sticking around can help motivate them to stick with an exercise plan.

In response to a major study in the Journal of the American College of Cardiology, Dr. I-Min Lee, an expert on the health benefits of exercise at Harvard-affiliated Brigham and Women's Hospital, advised the Heart Letter that weight loss isn't always a given among people who exercise regularly.

Some people have a harder time dropping excess pounds. If you are hoping that exercise will translate into weight loss, but it doesn't, take a look at calorie intake. "It's because the calories you take in exceed the calories you expend," says Dr. Lee. "If you want to lose weight, you can either exercise more or eat less—or do both."

In the study, overweight people who exercised consistently and lost weight achieved the biggest reduction in heart attack risk. Exercising without losing weight and losing weight without exercising offered a smaller benefit. Not surprisingly, those who didn't exercise and who gained weight were much more likely to develop high blood pressure, high cholesterol and face greater risks of developing cardiovascular problems.

"I think the findings are encouraging, because they clearly show that among the individuals who gain weight, if you maintain your fitness, you're at a lower risk compared to those who gain the same amount of weight but don't maintain fitness," Dr. Lee says.