Both strength and power training help keep muscles strong

DEAR DOCTOR K: What’s the difference between strength and power training? Is one better than the other?

DEAR READER: Your muscles enable you to carry groceries, climb stairs, get out of a chair and swing a golf club. The stronger and more powerful your muscles are, the easier all of these everyday tasks and others will be. But weak muscles turn seemingly simple tasks, like walking, into a chore. They are a primary reason why many people lose their independence as they age.

Strength and power training can curb or even halt these changes. They help your muscles function at a high level as you get older. And there are additional benefits. As you strengthen your muscles, you tone your arms and legs. You also burn more calories, since muscles require energy (calories) in order to function.

You can even help control various medical problems. For example, you can reduce your risk of heart disease, slow the advance of osteoporosis, ease arthritis pain, and help manage or prevent Type 2 diabetes.

So exactly what are strength and power training?

Strength training is a popular term for exercises that build muscle by harnessing resistance – that is, an opposing force that muscles must strain against. Strength training is sometimes called resistance training or weight training. Resistance can be supplied by your body weight, free weights such as dumbbells and weighted cuffs, elasticized bands or specialized machines. No matter what kind of resistance you use, putting more than the usual amount of load on your muscles makes them stronger.

Power training is aimed at increasing power, which is the product of both strength and speed. Power reflects how quickly you can exert force to produce the desired movement. Power can help you react swiftly if you trip or lose your balance, helping you to avoid a fall.

Some power moves are just strength-training exercises done at a faster speed. Other power routines rely on the use of a weighted vest. The vest is worn while performing exercises aimed at improving functions such as bending, reaching, lifting and rising from a seated position.

Try to do strength and power exercises two or three times a week. Allow at least 48 hours between sessions for your muscles to recover. (I’ve put descriptions and illustrations of a few strength-training exercises, along with their power variations, on my website, AskDoctorK.com.)

When I urge my patients to consider strength and power training, they understand the merits of keeping muscles strong as they age. But they often ask if strength and power training are as good as aerobic exercise in reducing the risk of heart attacks and strokes. There is growing evidence that they do, although the evidence is not yet as strong as for aerobic exercise.

I’ve adopted an exercise program of aerobic exercise four to five days a week and strength training twice a week. If new evidence causes me to change my mind about what’s best for me, I’ll change my routine.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.