Q: I am a 48-year-old woman with fibromyalgia. Among my most troublesome problems are fatigue and muscle weakness, which my doctor attributes to lack of physical activity. Are these common in fibromyalgia? Can anything help?

A: The problem you describe is common in people with fibromyalgia, but feelings of fatigue and weakness can occur in anyone who is inactive – whatever the reason. While a program of aerobic activity – brisk walking, jogging, swimming – may boost your energy level, the only way to strengthen muscles is through strength training or "resistance" exercise (in other words, weight lifting). And be prepared to work pretty hard at it.

To do resistance training properly, start with moderate weights, and slowly and progressively increase the amount of weight you lift. You should never work out more than three times per week; twice a week is probably best in your case. It's also important that you take time to warm up before lifting, cool down when you stop, and stretch plenty in between. 

The program I recommend in cases like yours is three sets of eight to 10 repetitions per muscle group, working at 60 to 80 percent of the most weight you are able to lift at once. This means you should find the last few repetitions quite difficult. This may aggravate your fibromyalgia at first, so you have to listen to your body. It's OK to be a bit stiff and achy the day after training, but persistent pain or pain in the joints is a warning that you're overdoing it.

The level of exercise I'm recommending is intensive, but such activity is the only known way to bulk up your muscles, and more importantly, to increase your strength. It is strength that makes people functional and independent. 

When you exercise, don't worry about your arms too much – concentrate on your legs, buttocks, back and chest. It doesn't matter if you work out in a gym or use fancy equipment, but if you have arthritis or other medical conditions in addition to fibromyalgia, ideally you should find a trainer who has experience with people who have those problems. (Ask your rheumatologist or physical therapist for a recommendation.) 

If you don't have access to or can't afford a trainer, consider an excellent book called "Strong Women Stay Young" (Bantam Books, 2005) by Miriam Nelson, PhD. It's not specifically about fibromyalgia, but the principles are applicable to everyone. Foremost, I recommend you go slowly at first, listen to your body and be patient. You'll see results in about eight weeks, so hang in there!

Ronenn Roubenoff, MD, Rheumatologist