By Pat Carragher - October 25, 2020
The next time you feel like pushing off that morning run, you may want to reconsider. A new study suggests that people who exercise between 8 and 10 a.m. can reduce certain cancer risks.
Researchers from the Barcelona Institute for Global Health and the Department of Epidemiology at the Medical University of Vienna looked at the exercise habits of more than 2,700 people. The study, published in the International Journal of Cancer, concludes that physical activity in the early morning was associated with a 25% lower risk of breast cancer, and a 27% lower risk of prostate cancer. Similarly, physical activity in the evening was associated with 25% lower risk of prostate cancer.
How sleep cycles impact cancer risk
Have you ever gone for a run after dinner, then had trouble falling asleep later that night? Exercising too late in the day can throw off your circadian rhythm, the 24-hour cycles that are part of the body's internal clock. Instead of producing melatonin, which helps you fall asleep, your body could be producing extra hormones that will actually keep you awake and alert instead.
Previous studies have shown that how we sleep can actually play a role in staving off disease.
“Disruptions to someone’s circadian rhythm has been linked with higher risk of cancer,” said Dr. Brian D. Gonzalez, assistant member of the Health Outcomes & Behavior Department at Moffitt Cancer Center. “Exposure to light, eating and physical activity at certain times can help retrain your circadian rhythm to get it back in line with your actual daily routine.”
"Exposure to light, eating and physical activity at certain times can help retrain your circadian rhythm to get it back in line with your actual daily routine."- Dr. Brian D. Gonzalez, Assistant Member, Health Outcomes & Behavior
It’s recommended not to work out less than three hours before going to bed, and make sure to drink plenty of water when working out.
Exercise is important no matter what time of day
Research has shown that doing recreational exercise can reduce a person’s risk of developing many different cancers. Though, according to the Centers for Disease Control & Prevention, nearly half of American adults failed to meet minimum physical activity guidelines.
Given the number of people who develop cancer each year, even something as small as changing the time you exercise could make a significant impact to reducing the effects of cancer. Gonzalez stresses that any exercise is beneficial to your overall health, regardless of when you choose to do it.
“It’s important to keep in mind that exercise has been shown in other studies to be linked with a lower risk of cancer,” said Gonzalez. “Even if this study suggests that physical activity at only certain times of day was linked with lower risk of cancer, exercise is critically important for lots of reasons. It helps you feel better, have more energy and it affects lots of biological processes that may themselves reduce risk of cancer.”