If you’re being treated for cancer with chemotherapy, radiation, or both, you know how taxing this regimen can be. The side effects are well-known: fatigue, pain, nausea, and neuropathy (pain caused by nerve damage), not to mention stress, depression, and anxiety.

Exercise can help you cope, says the American College of Sports Medicine, which certifies cancer exercise trainers in a program it runs in collaboration with the American Cancer Society. Whether you have cancer or are a cancer survivor, exercise can have a positive affect on your body weight, overall fitness, muscle strength, flexibility, and quality of life.

Plus, it appears that exercising makes cancer treatment itself go more smoothly, with fewer side effects. Kerry Courneya, PhD, professor of kinesiology, sport, and recreation at the University of Alberta in Edmonton, Canada, has done numerous studies on the benefits of exercise for cancer patients. Remaining as active as possible during treatment, he notes, can prevent fatigue during and after treatment, and there’s evidence it can also alleviate depression, improve sleep quality, and lessen joint pain and lymphedema (the buildup of lymph fluids under the skin, typically caused by removal or damage to lymph nodes during cancer treatment).

Here’s more about what exercise can do for you during cancer treatment:

In a study published in June 2015 in the Journal of Clinical Oncology, researchers at the Netherlands Cancer Institute divided 230 breast cancer patients into three groups. The first group engaged in a moderate-intensity aerobic and strength program, guided by a trained therapist; the second group was assigned to a low-intensity program, done at home; and the third group did no exercise at all. The women in the first two groups, who exercised either a lot or a little, all experienced less fatigue, pain, and nausea during chemotherapy. The women who benefited the most — who were able to tolerate chemotherapy the best — were those in the moderate-intensity program.

Allay Anxiety and Stress

In a report published in June 2016 by the Norwegian Institute of Public Health, a review of more than 100 studies found that exercise can improve cancer patients’ overall quality of life during treatment. For another investigation, conducted in Taiwan, researchers enrolled 116 lung cancer patients in a home-based program in which participants walked for about 40 minutes, three days a week. The study, published in February 2015 in the British Journal of Cancer, concluded that even this moderate amount of exercise over the course of treatment reduced participants’ levels of anxiety and depression.

Alleviate Neuropathy Pain

Chemotherapy-induced peripheral neuropathy (CIPN) is a form of nerve damage that includes burning pain, tingling, numbness, and sensitivity to cold in the hands, feet, or other parts of the body. In a study published in May 2016 in the Journal of Clinical Oncology, researchers randomly assigned patients receiving chemotherapy treatment to either an exercise or no-exercise group. The exercisers did a six-week at-home walking program, supplemented by gentle resistance training, and ultimately reported fewer symptoms of neuropathy.

Prevent Lymphedema

Lymphedema is swelling caused by a build-up of lymph fluid and is a common side effect of cancer surgery, specifically the removal of cancerous or potentially cancerous lymph nodes. Women who’ve had underarm lymph nodes removed as part of treatment for early breast cancer are at risk for this complication (the risk goes up with the number of nodes removed), and doctors often advise them to avoid exercises such as lifting weights.

Unfortunately, this recommendation runs counter to the findings of the Physical Activity in Lymphedema Trial, published in the journal Contemporary Clinical Trials. For this study, women who’d had lymph-removal surgery undertook a year-long program of supervised weight training. The results showed that women at high risk for lymphedema who lifted weights were 70 percent less likely to develop the condition than women at similar risk who did not weight train.

Improve Overall Fitness and Ease Recovery

Someone accustomed to a regular workout routine will find it frustrating to give up exercising during treatment, but even people who didn’t work out regularly before cancer will feel the negative effects of a suddenly sedentary lifestyle, says Robert Steigerwald, an exercise physiologist and certified cancer exercise trainer in Huntington, New York. Chemo and radiation may decrease your endurance, aerobic capacity, and muscle strength, which makes treatment tougher on you physically. Any amount you can work out, Steigerwald says, “puts you in a better place as you recover.”

The effects of exercise on cancer may have even more far-reaching impact, says Dr. Courneya. Researchers are investigating whether exercising improves responsiveness to treatment and long-term survival. “If exercise during treatment were shown to improve these cancer outcomes, I think that would be a game-changer,” Courneya says.

Advice to Keep in Mind Before You Lace Up

All cancers are different, as are all patients. Before you begin or resume exercising during treatment, be sure to talk to your oncologist or consult a cancer exercise trainer, and consider the following:

• Allow for “down” days — scaling back your workouts, for instance, when you’re experiencing the worst side effects of treatments.
• If you haven’t been regularly active before your diagnosis, begin with very low-intensity exercise; you might try taking a slow walk most days.
• Avoid public facilities, such as pools or locker rooms, that may expose you to infection.
• Avoid exercise or dramatically pull back if you are anemic (your red blood cell count is very low), neutropenic (your white blood cell count is very low), or thrombocytopenic (your platelet count is very low).
• Consider exercising with a trainer, friend, or caregiver, for safety.
• Stop working out and seek medical help if you become disoriented, dizzy, nauseated, short of breath, or feel any pain, such as muscle cramps or, particularly, chest pain.