Study after study has shown that exercise reduces the risk of cancer recurrence for cancer survivors. More than 200 studies have shown that the most physically active survivors have a lower risk of cancer recurrence than the least active cancer survivors. The data favoring exercise is strongest for survivors of breast cancer, colon cancer, endometrial cancer and prostate cancer.
The American Cancer Society recommendations for cancer survivors include 30 minutes of moderate to vigorous physical activity (above usual daily activities) five days a week for a total of 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise. The ACS also recommends strength training. Despite these expert recommendations, only 50% of Americans report that their weekly exercise meets these guidelines. The glass may be a lot less than half full because studies have shown that people frequently overestimate how much time and with how much intensity they exercise.
How much intensity is enough? Dr. Jennifer Trilk is an exercise physiologist at the USC School of Medicine Greenville. She reports that the talk test is a simple way to measure relative intensity. As a rule of thumb, if you’re doing moderate-intensity activity you can talk, but not sing, during the activity. If you’re doing vigorous-intensity activity, you will not be able to say more than a few words without pausing for a breath. Another way is to measure your heart rate. You can do this by feeling your wrist for your pulse, counting the heartbeats for 15 seconds and multiplying by four. Or you can purchase an inexpensive heart rate monitor. Moderate-to-vigorous exercise should raise your pulse to 50% to 85% of your maximum heart rate.
Your maximum heart rate is 220 minus your age in years. For example, if you are 60 years old, subtract 60 from 220 and that equals 160 beats per minute. Fifty percent of 160 is 80 beats per minute and 85% of 160 is 136 beats per minute. So the target heart rate for moderate-to-vigorous exercise for a sixty year old is between 80 and 136, with 103 in the middle. Overall, moderate intensity includes brisk walking, dancing, gardening and tennis. Vigorous intensity includes jogging, running, swimming laps and heavy gardening.
How much time is enough? The United States Physical Activity Guidelines recommend 150 minutes per week to obtain significant health benefits. That amounts to 30 minutes for an outing, five days per week. However, if you can’t reach 30 minutes per day, newer evidence suggests that any exercise is still beneficial. A recent study published in the Journal of the American College of Cardiology suggests that there may be some benefit to as little as five or 10 minutes of exercise per day. Researchers reviewed questionnaires filled out by 55,137 healthy men and women seen at the Cooper Clinic in Dallas, Texas, over 15 years. The 24% of the people who reported any running or jogging had a 30% lower rate of death compared to those who did not exercise. Among those who exercised at all, the benefits were the same for those who ran a lot or for those who ran for as little as five or 10 minutes per day. This encourages me to exercise at least five or 10 minutes on days when I cannot fit in 30 minutes.
If you are not exercising at all, I suggest that you start with a goal of five minutes per day and work your way up to 30 minutes. Exercising with a friend or with a group may help you establish a routine. If you would like to learn more about the benefits of exercise and nutrition for cancer survivors, call the Center for Integrative Oncology at (864) 455-1346. You may wish to schedule an integrative oncology consultation, where you can receive personalized exercise and nutrition recommendations.