Achy knees and joints caused by arthritis are not reasons to stop exercising.

Regular, modest exercise improves joint stability and strengthens muscles, according to the December issue of Mayo Clinic Women’s HealthSource. Exercise also improves mood, sleep, energy levels and day-to-day functioning. Best of all, people with arthritis who exercise regularly report less pain.

When a person avoids exercise, joints become less mobile and the surrounding muscles shrink, causing increased fatigue and pain.

A physical therapist or personal trainer can tailor exercise programs to health conditions and fitness levels. The key is to choose safe, appropriate activities and to take it slowly at first. A variety of activities can be safe and helpful for people with arthritis, including:

- Range-of-motion and flexibility exercises: Activities such as yoga and tai chi increase joint mobility. Doing range-of-motion exercises in the evening can reduce joint stiffness the next morning.

- Low-impact aerobics: Aerobic exercise improves overall fitness and endurance as well as muscle function and joint stability. Low-impact options include water aerobics, swimming, bicycling, walking or using equipment such as treadmills and elliptical trainers.

- Strengthening: Strength training builds the muscles around the joints to provide better support. These exercises may be done with one’s own body weight for resistance, with hand-held weights, resistance bands or weight machines.

- Lifestyle: Many everyday activities - gardening and housework - provide the health benefits of moderate physical activities.

For those with joint damage, some high-impact activities can make arthritis pain worse. It’s wise to consult with a physician before starting a new exercise regimen. Exercising should be stopped when it increases pain or swelling; causes joint popping, locking or giving way; leads to abdominal, groin or chest pain; or results in moderate-to-intense shortness of breath.

Mayo Clinic Women’s HealthSource is published monthly to help women enjoy healthier, more productive lives. Revenue from subscriptions is used to support medical research at Mayo Clinic.