Is physical activity good for you?
During COVID-19 times, it might be prudent to avoid cramped, indoor gyms. But outdoor activity in open spaces is invariably a healthy choice. We know that getting off the couch and out for a walk helps prevent obesity, Type 2 diabetes, and heart attacks. And good news! A recent report from the American Cancer Society says exercise also lowers the risk of seven types of cancers.
Dr. Charles Matthews of the National Cancer Institute in the U.S. pooled data from nine studies about how leisure-time activity affects 15 types of cancer. His results should act as a huge incentive to get people of all ages moving.
Matthews and his colleagues report that those who engaged in 7.5 to 15 hours a week of physical activity showed significantly lower risk of seven of the 15 cancers studied. The decrease became greater with more hours of activity.
For instance, moderate intensity activity was associated with 8 percent lower risk of colon cancer in men. If double the intensity, the benefit was 14 percent. Risk of breast cancer in women was reduced by 6 percent to 10 percent depending on the amount of exercise. For malignancy of the uterus, the difference was 10 percent to 18 percent; kidney 11 percent to 17 percent; myeloma 14 percent to 19 percent; liver 18 percent to 27 percent; and non-Hodgkin lymphoma in women 11 percent to 18 percent.
But how does exercise decrease the risk of these malignancies? It’s believed exercise decreases hormone levels that trigger some types of cancer. We also know exercise increases the immune response which helps fight cancer. Some malignancies are also linked to obesity. Exercise burns up calories and decreases obesity to help lower risk.
Exercise can help decrease the risk of these malignancies. But never forget that an active lifestyle sets you up for the physical and mental agility you want during your senior years, too. Back in the 1960s, a Japanese marketing campaign proposed “10,000 steps a day,” equating to about 5 miles. Most North Americans walk far less — under 5,000 steps on average.
There are some skeptics, like the writer Mark Twain, who claimed he'd been to the funeral of many friends who believed in exercise more than he did.
But it would be prudent for doctors to write on a prescription, “More exercise and use a pedometer.” Why count steps when we all know exercise is good for us? Research consistently shows pedometers are great psychological motivators. They inspire us to get walking.
Dr. Paul Dudley White, Harvard’s renowned cardiologist, rode his bicycle to work and was a firm believer in stepping it up. He taught, “If you want to know how flabby your brain is, feel your leg muscles!” Or as the British historian George Trevelyan remarked, “I have two doctors, my left leg and my right.”
Remember that walking is free, simple and convenient. There’s also no need to try and break the record of the one-minute mile or purchase expensive exercise machines.
Unfortunately, walking 5 miles daily for a 150-pound person burns up only 500 calories. And it is so easy to consume 500 calories. Just three of the wrong cookies can undo all that walking.
Exercise and watching calories have always been a tough sell to those who haven’t made it a lifetime passion. Michelle Obama got it right when she planted a vegetable garden at the White House and launched the Let’s Move initiative to help kids engage in physical activity. Starting young is ideal, but it’s never too late to start enjoying a daily walk. And don’t let the excuse of “no time” deter you.
Heed the Earl of Darby, who advised, “Those who do not find time for exercise will have to find time for illness.”