Give Me Strength: Why you need to lift weights
(Second of three articles on strength training)
Miriam Nelson, director of the John Hancock Center for Physical Activity and Nutrition at Tufts University’s Friedman School of Nutrition Policy and Science in Boston, continues her discourse on strength training.
Q. Can strength training turn back the clock?
A. Yes, but how much depends on your age. With very old people, we see a 6 percent to 10 percent increase in muscle mass. But they have so little muscle that the actual gain–a pound and a half or so–is small. I usually say that the 65-year-old woman who’s been strength training and doing some aerobic exercise for a year is biologically much more like a 40-year-old woman who is not doing any prescribed exercise. If the 40-year-old were exercising as much as the 65-year-old, she would be more like the 20-year-old who has been fairly sedentary. So at any age, if you’re exercising you’re going to be like a younger person who has not been exercising that much.
Q. You said that poor nutrition causes muscle loss. How?
A. About 25 percent of older women are marginally deficient in protein, and some aren’t getting enough calories or nutrients like calcium and vitamin D, which is particularly important for muscles. At any age you need enough protein to keep your liver, heart, muscles and all other lean tissues viable and healthy. When you don’t get enough protein, you start to lose lean tissue, and you lose skeletal muscle preferentially. That leads to frailty. The first sign is a compromised immune system. People get infections, poor skin, brittle nails, poor hair quality. The body starts shutting down. It’s mostly an issue for frail, homebound, older women. They don’t eat enough either because it’s an economic issue or because they can’t get to the supermarket. When you’re barely eating enough, the body uses protein for calories, which can lead to a deficiency.
Q. How much strength training do you have to do?
A. The American College of Sports Medicine recommends two to three times a week as optimal, and I agree. If you’re consistent with at least twice a week, you get good gains in bone, muscle, everything. Even one day a week is helpful, though not optimal.
Q. How long does it take?
A. About 30 to 45 minutes per session, because you need to do one or two sets of six to 10 exercises. And it should be moderate to high intensity, so we’re not talking about lifting one- or two-pound dumbbells. The weight should be such that you can lift it 10 to 12 times in good form, but after that it feels heavy and you can’t lift it correctly. Then you need to rest before you do another set. If you can lift it 15 or 20 times before you rest, the weight is too light. That’s more of an endurance aerobic activity, not a strength-building activity.
Q. How much weight should you start with?
A. I would start the 50-year-old woman with three pounds for a biceps curl. In a week she’d be up to four pounds. In a couple more weeks, she’d be up to five. And in a few more weeks, she’d be up to six pounds. It’s a moving target. When she gets up to 10 or 12 pounds–which is pretty typical because the biceps is a pretty strong muscle–the 10-pound weight will feel like the old four-pound weight did, because her muscles are stronger.
Q. If you can’t progress to heavier weights, you’re not building muscle?
A. Right. Many women think they can build muscles by lifting soup cans. Or they work out with three-pound weights week after week in a “tone and firm” class. That won’t make you stronger. The weights have to be heavier than soup cans. And if you don’t keep increasing the load as your muscles get stronger, you won’t progress very far.
Q. How many different exercises do you need to do?
A. Six to ten. That’s because you need to work different muscles. For example, you can do a biceps curl, which gets at the front of your arms. But you also want to do an overhead press, which gets at the triceps in the back of your arms and the deltoids in your shoulders. And then you might do a knee extension. You’re seated in your chair, you have some ankle weights on, and if you extend your leg out straight, that gets your quadriceps. Then, if you’re standing and you have ankle weights on and you do a curl back, that gets your hamstrings. That balances the quadriceps exercise. Then for core strength, you would do some sort of abdominal curl and then a back extension. So you’ve got six exercises right there. Six is pretty minimal, but it would still be awesome. The big thing is
Q. Can people do it at home?
A. Yes. On my Web site, strongwomen.com, we have animated programs and a free downloadable booklet. Our other site is go.tufts. edu/growingstronger, a program for men and women we did with the Centers for Disease Control and Prevention. It’s also animated and downloadable. And fitness centers are now much more receptive to having older adults. Also, many community centers have strength-training programs.
Q. Can people just start on their own?
A. If you’re relatively healthy, whether you’re in your 40s or early 80s, you can do these programs on your own or at a community site. But the frailer you are and the more complicated your medical condition–for example, if you have severe osteoporosis or arthritis–the more important it is to talk to a physical therapist or personal trainer to customize your program. You don’t want to do any harm.
Copyright 2004 CSPI. Reprinted with permission from Nutrition Action Healthletter, 1875 Connecticut Ave. N.W., Suite 300, Washington, D.C. 20009-5728.