For the 20 million American adults with osteoarthritis, the prescription to make love frequently makes perfect sense. It's even endorsed by the Arthritis Foundation.

First, “arthritis” is not a disease. It’s a symptom. It simply means joint inflammation, and the soreness, stiffness, and pain that typically accompany it. Dozens of illnesses cause arthritis. But quite often the doctor explains that what you have is the most common form of joint inflammation, osteoarthritis (OA), which is what people usually mean when they say “arthritis.” According to the American College of Rheumatology, osteoarthritis afflicts more Americans than all other forms of arthritis combined.

Osteoarthritis typically results from decades of joint wear and tear, and especially from a history of joint injuries. Joints are lined with cartilage, the tough, flexible, shock-absorbing material that keeps the bones from grinding into one another. In osteoarthritis, this cartilage breaks down, causing pain, tenderness, swelling, range of motion limitations, morning stiffness, stiffness after rest, and pain aggravated by strenuous use of affected joints. Most people experience their worst achy stiffness first thing in the morning, with discomfort diminishing as the day progresses.

Risk factors for osteoarthritis include:

• Age. Joint abuse accumulates with age.

• Weight. The heavier you are, the more you place on your joints. Today, most Americans are heavier than they were a generation ago. In fact, more than half of American adults are now considered overweight. Not surprisingly, rates of OA are rising and the condition is affecting younger (heavier) people.

• A history of injury. That knee you messed up in high school sports may become OA later in life.

• Repetitive tasks. OA of the hands has increased considerably since so many Americans spend their lives working keyboards.

to the Rescue

To manage OA, doctors used to advise minimizing activity. Today we know that reduced activity actually leads to more pain, not to mention loss of muscle strength, which makes it harder to be active. Inactivity also contributes to weight gain, which aggravates OA.

Nowadays, doctors and the Arthritis Foundations urge those with osteoarthritis to be as physically active as the condition allows, particularly with low-impact exercise that gently moves joints through their full range of motion. Gentle, full-range-of-motion exercise:

• Minimizes pain, reduces inflammation, and helps keep joints supple.

• Promotes blood flow into cartilage, which keeps it healthy.

• Strengthens the muscles around the joints, which helps support them.

• Releases endorphins, the body’s own pain-relieving compounds.

• Helps control weight.

Many studies show that regular exercise reduces the pain, stiffness, and disability of osteoarthritis. Cornell researchers recruited 102 people with OA of the knee and encouraged some to take regular walks, and the rest to take anti-inflammatory pain relievers. After eight weeks, the drug group reported no changes in their condition, but those who took up walking reported 27 percent less pain and a significant decrease in use of pain .

However, you might wonder: Won’t exercise wear out my joints? That’s possible, but only if you overdo it with high-impact activities, for example, running or contact sports.

The best exercise for you depends on which joints are affected and how severely. But in general, good forms of exercise for OA include: walking, gardening, swimming, cycling, in-pool calisthenics—and sex.

“Sex is terrific exercise for people with osteoarthritis,” says Palo Alto sex therapist Marty Klein, Ph.D. “It provides gentle, low-impact, massage-like exercise. It moves the major joints through their full range of motion. It releases pain-relieving endorphins. And the closeness of lovemaking, the feeling of being loved, also helps relieve pain.”

Here’s how to incorporate lovemaking into OA self-care:

• Make sex dates in advance. Living with any chronic condition requires lifestyle adjustments and planning. Scheduling sex allows you to prepare in advance, perhaps with other gentle exercise (walking), or by taking pain medication an hour beforehand.

• Get some other exercise before sex. To feel intimate, many couples enjoy spending some close, nonsexual time together before they disrobe. Walking, gardening, yoga and similar workouts warm up the joints for sex.

• Bathe or shower beforehand, possibly together. Heat soothes the joints. Bathing and showering not only reduce discomfort, they also offer a sensual way to begin sexual arousal.

• Take your medication. About half of OA sufferers notice benefit from daily doses of the supplements, glucosamine and chondroitin. In addition, an hour or so before sex, consider pain medication. If you feel only pain, acetaminophen (Tylenol) should help. If you also notice inflammation take an anti-inflammatory pain reliever—aspirin, ibuprofen (Motrin, Advil), or naproxen (Aleve). However, acetaminophen increases risk of liver damage, and aspirin, ibuprofen, and naproxen may cause stomach distress.

• Move your whole body. Don’t rush into intercourse. The best exercise for the OA moves the joints—fingers, wrists, elbows, shoulders, neck, back, hips, knees, and ankles—through their full range of motion. Incorporate whole-body massage into your lovemaking. Roll around together. Work all your joints. This type of lovemaking not only helps manage OA, it’s also the kind of lovemaking sex experts recommend as the most erotic and satisfying.

• Try sex toys. OA stiffens many people’s fingers, which can make loving caresses difficult. Vibrators may help.

• Make adjustments. OA often affects the knees. If you or your lover has chronically stiff, sore knees, experiment with sexual positions that don’t strain them. For example, you might decide to forego doggie-style intercourse with both of you on your knees.

• Check in. Before, during, and after sex, discuss the moves that feel best, and the ones that hurt. Over time, develop a sexual style than emphasizes feel-good moves.

• Remain sexual. Some people think: I’m in pain. Pain ruins sex. Therefore, I’m not going to have sex any more. Others think: I’m in pain. But I’m a sexual person. I’m going to make accommodations and remain as sexual as I can under the circumstances. OA experts recommend the latter. Sex provides gentle, low-impact, massage-like exercise that moves the joints through their full range of motion, while releasing pain-relieving endorphins. In other words, sex helps minimize the pain and stiffness of OA.

Finally, if you experience more than two weeks of persistent joint pain and/or inflammation that doesn’t respond to heat, gentle exercise, and over-the-counter drugs, see a doctor.