If you have cancer or have had it in the past, then you’ve already discussed treatments with your oncologist.

So answer me this: Has your oncologist ever brought up the topic of exercise during any of your conversations and been very specific about it—as in, what types of physical activities you should be doing and how often you should be doing them?

Odds are, he or she hasn’t, according to a new study.

This is alarming, since past research has shown that exercise is associated with improvements in a wide range of cancer-related issues, such as reducing fatigue and enhancing physical quality of life, according to a meta-analysis done by researchers at Duke Cancer Institute in Durham, North Carolina. Exercise may also help prevent cancer recurrence and cancer-related death. One study done by researchers at Harvard Medical School, for example, found that the risks of breast cancer recurrence, breast cancer death and death (from any cause) were 26% to 40% lower in women who exercised most, compared with those who exercised least.

Why are oncologists talking more about pills than Pilates?

And what, specifically, about exercise should cancer patients—and cancer survivors—know?

I spoke with an expert to find out…

CANCER PATIENTS ARE IN THE DARK

In the new study, researchers interviewed 20 lung cancer patients, and not one participant reported receiving specific instructions from his or her oncologist about exercise—other than a vague suggestion to “stay active.”

This is not to say that oncologists don’t care about your well-being, emphasized lead study author Andrea L. Cheville, MD. They are simply more apt to zero in on their area of expertise—attacking your cancer and killing it with drugs, radiation, surgery, etc.—as opposed to talking about easing symptoms and preventing recurrence, she said.

IT PAYS TO GET MOVING

“We still don’t know exactly why exercise helps reduce symptoms and cancer recurrence—it may be that it stimulates metabolism, modulates hormones, boosts immunity and/or reduces oxidative damage to cells (or some combination of these factors), but we do know that it helps,” Dr. Cheville told me.

It’s important for all people to exercise, of course, not only cancer patients. But it’s particularly important for cancer patients and cancer survivors to be physically active because having cancer challenges a person’s fitness in a variety of ways.

Past research has shown that chemotherapy, for example, is associated with a loss of lean muscle, and it can make patients feel more achy and fatigued than usual. These problems tend to make exercise less appealing, though physical activity actually is what helps solve those problems by building muscle and relieving achiness and fatigue. Cancer patients and survivors are already at a physical disadvantage, and if they exercise progressively less, they will lose even more strength and stamina and be less able to fight off recurrence of the disease.

EXERCISE THAT SUITS YOUR NEEDS

If your oncologist isn’t bringing up exercise, Dr. Cheville suggests you should broach the topic yourself. Then, if the doctor doesn’t have specific advice about it, ask for a referral to a physical therapist or personal trainer who does have specific experience in working with cancer patients and/or survivors.

Come to think of it, I’d go see such professionals even if my oncologist did know a bit about exercise—they are the real specialists in it.

Anyone with cancer can exercise, Dr. Cheville assured me, but the trick is making sure that you go about it safely and effectively. There is no one-size-fits-all workout plan to follow. For example, a woman receiving radiation for breast cancer may be extra tired, so aggressive exercise would not make sense in this context. Instead, she would benefit from gentle, progressive stretching. On the other end of the spectrum, a man who has been in remission from prostate cancer for five years is much better able to handle intense endurance and strength-training exercises, such as weight lifting or jogging. Most patients fall somewhere in between those two examples, so it’s usually best to start small—often with light stretches or walking—and then progress gradually into more forceful moves, gauging comfort along the way. And the program should be molded around any targeted problems from the cancer or the therapy, such as not using a sore body part that’s healing from an incision or avoiding movements that cause dizziness if a patient is easily nauseated. That’s why it’s important to ask your physical therapist or trainer for a carefully individualized program.

Also call your local YMCA or click here, since the Livestrong nonprofit has partnered with YMCAs in 25 states across the country to provide specialized exercise programs for cancer survivors.