BEST
Interval training: This is unrivaled for preventing heart disease and diabetes, losing weight, and efficiently improving fitness. The strategy: Combine short bursts of high-intensity exercise with slightly longer periods of active recovery. So if you're a walker, you might alternate 3 minutes at normal speed with 1 minute at a brisk pace. Continuously raising and lowering your heart rate improves vascular function, burns calories, and makes the body more efficient at clearing fat and sugar from the blood.
Interval training: This is unrivaled for preventing heart disease and diabetes, losing weight, and efficiently improving fitness. The strategy: Combine short bursts of high-intensity exercise with slightly longer periods of active recovery. So if you're a walker, you might alternate 3 minutes at normal speed with 1 minute at a brisk pace. Continuously raising and lowering your heart rate improves vascular function, burns calories, and makes the body more efficient at clearing fat and sugar from the blood.
Core workouts: The reason I like Pilates, which strengthens my core muscles and improves flexibility and balance, is that it doesn't just help me play golf and tennis better, it helps me live better. In order to exercise vigorously—as well as carry groceries upstairs and weed the garden—you need a solid foundation.
Yoga: The calm it provides lowers blood pressure, making blood vessels more elastic and promoting heart health. It also strengthens your core.
Being active all day: People who are active in little ways the entire day (cleaning, gardening, running errands) burn more calories and are generally healthier than those who exercise for 30 to 60 minutes and then sit at a computer. Wear a pedometer to measure how active you are outside of your exercise time.
Worst
Running long-distance on pavement: I did a lot of this until various aches and pains, plus all the injured joggers I saw in my practice, made me realize that humans aren't designed for long-term pounding. Although running this way strengthens the heart, it wears out the body.
Any type of vigorous exercise you haven't trained for: This can range from shoveling snow to biking 20 miles on the first spring day. The excessive adrenaline that's released can prompt a heart attack in those at risk. For the same reason, never exercise hard without warming up.
Finally, don't let science (or even me) dictate your exercise. Research may show swimming is tops, but if (like me) you don't enjoy it, then don't torture yourself. Find something fun that you'll do consistently. Your mood will get a boost as well.