6/14/2014 12:26:00 PM Good exercise program involves more than aerobic activities
DEAR DOCTOR K: You've written that a complete exercise program involves a combination of activities. Can you discuss these exercises? How often should I do them?
DEAR READER: All-around fitness calls for a combination of aerobic, strength, flexibility and balance exercises.
Let's start with aerobic activities, which are great for burning calories and paring down unwanted fat. These activities -- think of walking, biking, running and swimming -- push large muscles to repeatedly contract and relax. They temporarily boost your heart rate and breathing, helping to build up your endurance.
Try to get at least 150 minutes of moderate-intensity physical activity (such as a brisk walk) or 75 minutes of vigorous-intensity physical activity each week. (I've put a description of exercise intensity on my website, AskDoctorK.com, to help you judge how hard you're working.)
Strength or resistance training works by forcing muscles to strain against an opposing force such as free weights or a resistance band. Strength exercises build muscles and protect against bone loss. They also preserve functional strength. Functional strength allows you to lift groceries, climb stairs, or sprint to the bus stop with ease.
Aim to perform a complete strength-training routine two to three times per week. Your routine should work all the major muscle groups. Give your body at least 48 hours to rest between strength-training workouts.
Flexibility exercises like stretching, yoga and Pilates gently reverse the shortening and weakening of muscles that typically comes with age. Shorter, stiffer muscle fibers are more vulnerable to injuries. They contribute to back pain and balance problems. Flexibility exercises help stretch and strengthen muscles. Well-stretched muscles can more easily achieve their full range of motion, which makes it easier to reach, bend and stoop during daily tasks.
Perform flexibility exercises at least two to three times a week. Hold stretches for 10 to 30 seconds. Repeat each stretch four times.
Balance exercises help improve stability. They offer an excellent defense against falls, which can cause disabling bone fractures. Activities that enhance balance include tai chi, yoga and Pilates. You can do balance exercises two to seven days a week.
All my adult life, I took aerobic exercise very seriously. I jogged nearly every day. In the past 15 years, I've switched to a non-impact type of aerobic exercise with an elliptical cross-trainer. But I never really took the other types of exercise seriously.
When my muscle bulk started to shrink (which it had never done earlier in life), I learned the value of strength training. And when I had a couple of thigh and calf muscle sprains, I learned the value of flexibility training.
I suspect that, before long, I'll also be doing tai chi regularly. That's not because it's in vogue, but because of the proven health benefits I've reported in this column before. And also because a large fraction of the human race has been doing it for centuries -- and swears by it.
(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.)