- Researchers say engaging in regular physical activity may help improve cancer survival.
- They add that even people who were inactive prior to their diagnosis may benefit from exercise.
- Experts advise starting slow with a new exercise regimen and working toward your goals.
- “Microwalks” are a simple way to begin and don’t require special equipment.
Exercise has numerous health benefits, with a large body of evidence suggesting that regular physical activity can help you live longer.
Now, a new large-scale study published on February 17 in JAMA Network Open found that participating in moderate to vigorous physical activity after a cancer diagnosis may help improve survival rates.
Several less commonly studied cancers were examined in the study, including bladder, endometrial, kidney, lung, oral cavity, ovarian, and rectal.
The authors also noted that even individuals who were inactive prior to their cancer diagnosis may find taking up exercise beneficial.
The study pooled data from six major long-term health studies, including the Cancer Prevention Study-II Nutrition Cohort, the Health Professionals Follow-Up Study, the National Institutes of Health–AARP Diet and Health Study, the Nurses’ Health Study, the Nurses’ Health Study II, and the Women’s Health Study.
Altogether, 17,141 adults were included who were survivors of one of the seven cancers studied.
Participants had completed surveys about their leisure-time physical activity both before and after their cancer diagnosis. On average, the data were collected about 2.8 years after their diagnosis, which allowed the researchers to avoid the period during treatment, when they were likely to be less active.
Physical activities were classified based on intensity, focusing on moderate to vigorous activities such as brisk walking, running, swimming, or cycling.
Activity was measured in metabolic equivalent task hours per week (MET-h/wk), a standard method for reporting energy expenditure.
To categorize activity levels, the study used current physical activity guidelines, which recommend 7.5 to 15 MET-h/wk (equivalent to 150 to 300 minutes of moderate exercise per week). Activity levels ranged from no physical activity to more than triple the recommended amount.
The researchers tracked cancer-related deaths over an average follow-up of nearly 11 years.
Statistical models were used that accounted for factors such as age, sex, race, smoking habits, alcohol use, cancer stage, and treatments like chemotherapy and radiation.
The analysis also considered changes in physical activity from before to after diagnosis to understand the impact of becoming active or inactive over time.
To minimize bias, the researchers excluded deaths occurring within two years of the post-diagnostic activity survey in sensitivity analyses.
Upon analysis of the data, the researchers found that any amount of moderate to vigorous physical activity after cancer diagnosis was linked to a lower risk of death from cancer.
The effects were observed in survivors of bladder, endometrial, lung, and ovarian cancers — even when it was less than the recommended activity level.
Bladder cancer survivors who reported some physical activity had a 33% lower risk of cancer death compared to those who were inactive, according to the authors.
Additionally, when participants met the recommended activity levels, endometrial cancer survivors had a 60% lower risk, while lung cancer survivors saw up to a 62% reduction in risk.
Survivors of oral and rectal cancers benefited most when they engaged in physical activity amounts equal to or greater than double the current guidelines.
Among oral cancer survivors, those who exercised more than double the recommended level had a 61% lower risk of cancer death than inactive survivors. Rectal cancer survivors showed about a 43% lower risk when meeting these higher activity levels.
Additionally, although the results for kidney cancer survivors were not statistically significant, the trend suggested potential benefits for these patients with higher activity levels.
The study further highlighted that lung and rectal cancer survivors who were inactive before diagnosis but became active afterward experienced significantly lower cancer mortality risk, suggesting that it is never too late to gain survival benefits from physical activity.
The researchers noted that even after controlling for potential confounders and conducting sensitivity analyses excluding early deaths, which could have indicated people were less active due to poorer health, the link, although slightly weaker, still held up.
These findings add to previous research, which has looked at more common cancers such as breast, prostate, and colorectal.
Milica McDowell, an author, exercise physiologist, and associate vice president of education at US Physical Therapy, told Healthline that walking is the easiest way to start exercising. McDowell wasn’t involved in the study.
Walking doesn’t require any special training or equipment, and you can start with what McDowell calls a “microwalk.”
“[A] microwalk is a 5-minute walk or 500 steps; these can be done throughout the day as little snacks to break up sitting or other activities and will accumulate in order to create benefit throughout the day,” she explained. Over time, you can work up to longer walks.
McDowell added that your step count can accumulate over the course of the week, so you don’t have to achieve your walking goals all at once.
To determine whether you’re getting enough moderate to vigorous physical activity, McDowell said you can subtract your age from 220 and multiply by 0.7 to determine the heart rate you need to achieve. For vigorous activity, do the same, but multiply by 0.8.
For example, a 40-year-old would need to reach a heart rate of at least 126 bpm to achieve a moderate or greater intensity, she explained.
“Most individuals feel somewhat out of breath and are unable to easily talk while exercising,” she added, describing what vigorous activity should feel like.
Dale Boren Jr., a physical therapist and regional director at Physical Therapy Central and Clinic Director at Physical Therapy Central, of Elk City, OK, said one of the primary limitations faced by cancer survivors is fatigue. He advised starting slowly and working your way up. Boren Jr. wasn’t involved in the study.
The goal, he said, is to eventually engage in 150 minutes of moderate physical activity each week, about 30 minutes per day, 5 days per week. McDowell added that 75 minutes of vigorous activity is also an option.
When you become better able to tolerate it, Boren recommended 2 days of strength training with light weights, elastic resistance, and other forms of body weight movement and exercise.
“Learn to listen to your body, monitor for pain using 24-hour symptom behavior, monitor for fatigue, soreness, tiredness, and incorporate breaks when appropriate,” Boren said.
If you’re not sure where to begin, Boren said that your doctor, a physical therapist, or a certified trainer can help guide you.
More importantly, it’s helpful to remember that exercise doesn’t have to feel like a chore.
“Make movement and exercise fun, choosing movements and activities you enjoy, such as dancing, biking, hiking, yoga, or walking, and if possible, find a friend or family member to exercise with you for support and accountability,” he said.
