Some days, it seems regular exercise has become a panacea — good for the heart, good for blood pressure, good for glucose levels, good to limit sad days and depression.

But what about people tormented with the pain and stiffness of osteoarthritis, particularly in the knees and hips? What are they supposed to do?

There was an era when ethical medical practice demanded a no-movement solution for people in pain. Not anymore. Today, the more than 50 million adult Americans with arthritis are advised to seek the same 150 minutes a week of moderate exercise as everyone else.

Arthritis is actually a blanket term for more than 100 related conditions that frequently attack the knees, hips, feet, spine and hands. Osteoarthritis, the most common form, is a wear-and-tear condition that results from aging, being overweight, injuries and genetic factors. When a joint’s articular cartilage — the tissue that covers the ends of bones — wears down, bones start rubbing against bones. This often causes pain, swelling and stiffness.

If arthritis pain is caused by bone rubbing against bone, why move?

“A joint like the knee joint doesn’t have a blood supply, so it needs movement to swish around the fluids that deliver nutrients to the cartilage and other tissues,” says Marcy O’Koon, senior consumer health director at the Arthritis Foundation and editor of Arthritis Today magazine.

“Exercise should be part of treatment for most arthritis, because inactivity increases joint damage,” sports medicine doctor Gabe Mirkin writes in his DrMirkin.com newsletter. Mirkin has been studying the relationship between exercise and arthritis for a half-century. Once an avid runner, he switched to bicycling years ago, and at 84, he rides a tandem bike with his wife in addition to doing solo rides. He advises, “Choose a non-impact sport like walking, cycling, swimming or cross-country skiing, or use exercise machines that support your feet, so they don’t pound the ground.”

Moderate walking is usually the go-to exercise for those with osteoarthritis. Walking is inexpensive, low-force-producing and simple, requiring no special equipment or facilities. It builds cardiovascular fitness and strength, reduces pain, and improves mood.

But even walking proves too difficult for some sufferers, especially those who are overweight and/or have not been physically active. In that case, Allentown, Pennsylvania, orthopedist Laura Dunne frequently advises osteoarthritis patients to begin with aquatic exercise.

“When you get in water, you take gravity and pounding out of the equation,” she says. “At the same time, water walking or water jogging strengthens many of the same muscles that are used on land.”

Dunne also likes stationary bikes, noting that it’s important to adjust the seat height so the knee doesn’t flex too much while pedaling.

There is a lot of research to support the ability of moderate exercise to safely combat arthritis. Among findings:

A year ago, the British Journal of Sports Medicine published a review of randomized, controlled trials. It found no evidence that exercise harms the “articular cartilage in participants at increased risk of, or with, knee” osteoarthritis.

A 2015 Cochrane Review reported less pain, better physical functioning and a higher quality of life among osteoarthritis subjects who exercised vs. those who didn’t.

And a recently published systematic review and meta-analysis concludes that yoga may reduce knee pain and stiffness while enhancing physical functioning. Be cautious, however, because some yoga postures put too much pressure on one foot and leg or bend the knee too far. Don’t do anything that hurts. The Arthritis Foundation (www.arthritis.org) offers a variety of exercise videos on its website.

For those new to exercise, the Arthritis Foundation suggests doing a mild warmup to get past the discomfort and finding an exercise or walking partner to improve your likelihood of getting out there.

“Getting started is tough for people with arthritis, no doubt about it,” O’Koon says. “But once you become consistent, exercise is self-reinforcing, because it gets easier, you lose weight, you gain strength, you experience less pain, and you feel better emotionally.”

For decadeslong vigorous athletes experiencing arthritis pain, experts suggest switching routines over stopping completely — bicycling instead of running, for example. Don’t choose all or nothing; opt for moderation.

Whether you’re a recent or a lifelong athlete, there will be pain. While NSAIDs — over-the-counter, inflammation-reducing painkillers such as aspirin, ibuprofen and naproxen sodium — can help, they do have occasionally dangerous side effects and should not be used for more than 10 days without consulting with a doctor.

Walking poles, knee braces and cushioned footwear can also take some stress off the knees. A study published in 2009 concluded that walking poles reduce knee forces by 27%. Exercising both the arms and legs at the same time also increases calorie burn. Braces are helpful early in a workout, says Casey Kerrigan, a Harvard-trained rehabilitation therapist, because they increase your knee “proprioception,” or awareness. This helps you listen to your body and make appropriate decisions. Kerrigan adds that you don’t want to wear braces all the time, or you will limit muscle growth that can assist knee stability.

Kerrigan hit the global health headlines in 1998 when the Lancet published her study showing that high-heeled women’s shoes dramatically increase forces across the knee joint. Eleven years later, she left a tenured position at the University of Virginia to begin manufacturing Oesh shoes for women in Charlottesville. (Women receive about 60% of knee replacements.)

Kerrigan has watched as Nike and other major companies developed new shoes with revolutionary thick, cushioned midsoles.

“These might be a good option for those with knee pain; the flatter the heel, the better,” she says.

Amby Burfoot is a freelance writer and a member of the Running Hall of Fame. His most recent book is “Run Forever: Your Complete Guide to Healthy Lifetime Running.”