It turns out that people who maintain a stable weight -even if they are a little heavy-through their 40s and 50s are less at risk for heart disease than people who suddenly develop middle-age spread.

National Institute of Health researchers measured the frequency of metabolic syndrome, which is a cluster of risk factors including high blood pressure, high blood glucose (sugar), high triglyceride levels and low levels of good cholesterol and a large waistline (over 40 inches for men and 35 inches for women). People with three or more of these have a higher risk of heart disease. The study found that subjects who maintained a constant body weight were significantly less likely to develop metabolic syndrome than those who experienced a sudden weight gain. So maintaining a stable weight throughout your life is almost as significant as maintaining an ideal weight.

Weight maintenance is based on balancing the calories you consume with calories you expend. While most people focus on the "diet" side of the equation, there is increasing emphasis on getting enough regular physical activity to balance the equation. Enough exercise, experts advise, means 30 minutes of moderate activity every day.

According to Dave Martens, clinical exercise physiologist in Doylestown Hospital's Cardiac Rehab Department, it isn't necessary to engage in intense activity, such as jogging or vigorous workouts at a gym. In fact, pushing too hard is counterproductive, often leading people to quit and do nothing. Moderate walking or exercise on a bike or rower, for example, will suffice. "That means going at a rate which has you breathing faster than you breathe when you are at rest, but not as intense as a jog," he explains.

So, besides a formal exercise program, there are simple things you can do that will make a difference. Take a walk after lunch. Park a little farther away from your destination and walk the extra distance. Pick up the pace a bit. Take the stairs instead of the escalator. Bend and stretch often. The important thing is to keep moving ... every day.