IN THE PAST, IT WASN’T UNUSUAL for doctors to tell patients receiving cancer treatment to take it easy. “Now we know that’s the absolute worst thing you can do,” says Jessica Scott, an exercise physiologist at Memorial Sloan Kettering Cancer Center in New York City. “It’s almost like fatigue begets fatigue.” Regular physical activity is now recommended as a way to manage the aftereffects of cancer and its treatment.

Studies show that exercise provides various benefits to people with cancer, both during and after treatment. “It’s typically a good idea to check with your physician to see if there are any risk factors you have prior to starting an exercise program,” Scott says. Not many activities are off-limits, she adds, while noting that, for example, people who have bone metastasis or those who have had a stem cell transplant might need to avoid contact sports. Walking, cycling or swimming “are all good alternatives,” says Scott.

Watch Out for These Signs

Jessica Scott, an exercise physiologist at Memorial Sloan Kettering Cancer Center, says certain symptoms like chest pain, excessive shortness of breath, lightheadedness and joint pain are warning signs that you should stop exercising and contact your doctor.

She also advises that you should call your doctor if you experience extreme fatigue or swelling at a time when you aren’t exercising.

Exercise recommendations for people with cancer are generally the same as for healthy adults—at least 150 minutes of moderate-intensity aerobic activity along with muscle-strengthening activities two or more days per week, according to the American College of Sports Medicine. If you haven’t been exercising, start with 10 to 20 minutes per session, three days a week, and add five minutes more per session each week “so it’s a very slow and gradual progression,” Scott says. Exercise professionals can now receive specialized training to ensure they can meet the needs of cancer patients.

Livestrong at the YMCA offers a 12-week small group program for people with any type of cancer at any point in their survivorship, although they’ll need their doctor’s permission to participate during treatment. The program is offered for free or at minimal cost to participants in 707 communities across 42 states. Ann-Hilary Heston, director of Chronic Disease Prevention Programs at YMCA of the USA, says, “We train our instructors to design an exercise intervention that meets the needs of each cancer survivor. So [programs are] based on their cancer diagnosis, what their cancer treatment was, and then what types of side effects [they’ve had] as a result of treatment.” All classes include cardiovascular conditioning, strength training, and balance and flexibility exercises.

The program has been shown to improve cardiovascular endurance, reduce fatigue and improve overall quality of life, Heston says. Beyond that, it’s about “giving [participants] a place to feel a part of a community.”

If you can’t find a local Y program or a certified trainer, Scott recommends simply walking. “It’s really about getting out there and getting active [to reap] the benefits for both short-term and long-term health,” she says.