Goal: Ease Osteoarthritis Pain

Type of exercise: Gentle stretching exercises  (tai chi and yoga) are good options) or water-based exercise such as swimming or water aerobics during a flare. Add strength training for longer-term benefits.

Frequency: Ideally, do 30 minutes a day three times a week, but even just 20 minutes three times a week can help.

Intensity: Mild or moderate.

How it works: Although it may be tempting, the last thing you want to do during a flare is to stop moving. “When you exercise, your body releases pain-relieving chemicals, including endorphins,” says McCall. Although the mechanism isn’t entirely understood, physical activity also appears to reduce cellular inflammation that could otherwise exacerbate inflammatory conditions, including arthritis.

The evidence: Strong. A report in the Cochrane Database of Systematic Reviews that looked at 32 studies of people with knee osteoarthritis (OA) found that land-based exercise was as effective for knee pain as non-steroidal anti-inflammatory drugs (NSAIDs), such as naproxen (Aleve) or ibuprofen (Advil). Another review of eight trials that studied the effect of exercise on pain in hip OA, which was published in Evidence Based Medicine, found that exercise reduced the patient’s experience of pain by almost 50 percent.

Goal: Reduce Fibromyalgia Pain and Fatigue

Type of exercise: A mix of aerobic activity, flexibility training and strength training is most effective.

Frequency: Start with as much as you can do – even five minutes is fine – and work up to a total of 120 to 180 minutes per week.

Intensity: Mild to moderate.

How it works: Fibromyalgia is just beginning to be understood by the medical community, and because of that, experts aren’t entirely sure how exercise alleviates fibromyalgia-related pain. But the prevailing theory is that during exercise, the body releases endorphins, chemicals that act as natural pain relievers, says Jacob Teitelbaum, MD, medical director of the nationwide Fibromyalgia and Fatigue Centers. Exercise also increases energy by stimulating the cardiovascular and central nervous systems.

The evidence: Limited, but growing. The results of a study of 20 women with fibromyalgia published in the Archives of Physical Medicine and Rehabilitation found that a combination of strength training and aerobic exercise improved symptoms, particularly fatigue.

Goal: Relieve Depression

Type of exercise: Aerobic exercise includes activities such as biking, walking, jogging, swimming and aerobics.

Frequency: 30 minutes at least three times a week. That said, the effects seem to be somewhat dose-dependent, so exercising most days of the week is ideal. 

Intensity: Moderate to vigorous.

How it works: “There’s good evidence that aerobic activity increases the  brain's levels of serotonin, dopamine and norepinephrine -- three neurotransmitters that elevate mood,” says Stacey Rosenfeld, PhD, a licensed clinical psychologist in private practice and staff psychologist at Columbia University Medical Center in New York City. What’s more, she adds, “Completing even a short workout gives you a sense of accomplishment, and self-esteem is tied to a reduced incidence of depression.”

The evidence: Several studies have shown that exercise positively impacts mental health. One study from the Pennington Biomedical Research Laboratory at Louisiana State University in Baton Rouge, La., found that sedentary women who began exercising even moderately reported improvements in their quality of life, a measure of the physical and mental skills required to cope with everyday challenges. The more exercise the women got, the better they felt, even if they didn’t lose weight.