About 10 years ago a Chicago newspaper columnist dispensed sound advice to graduates that latter became known as The Sunscreen Speech. Mary Schmich’s smart commentary gained wide exposure thanks to an Internet hoax and a schmaltzy Top 40 song using the essay as lyrics. I was reminded of Schmich’s opening line — “Wear sunscreen.” — after reading a new study showing marathoners are more susceptible to skin cancer than the general population.
Researchers at a medical university in Graz, Austria studied 210 marathon runners and an equal number of nonmarathoners for changes in skin over time. What they discovered was that the distance runners stood a better change of developing “age spots” and lesions that can lead to common skin cancers like basal cell and squamous cell carcinomas.
Prolonged exposure to sunlight from hours of daytime running only explained part of it. When you sweat, you reduce protection from harmful ultraviolet rays and increase the risk of sunburn. But the researchers say a big contributor is the sheer intensity of marathon running. “Excessive exercise,” as they referred to marathon training and race-day activity, suppresses the body’s immune function. This also explains why distance runners tend to tend to catch a cold or the flu as their training peaks.
What may be surprising is how little training it takes to increase skin cancer odds. A third of the marathoners in the study ran up to 25 miles a week. Only 15 percent ran more than 45 miles weekly, while the rest averaged between 25 and 45. And only half of those tested wore sunscreen.
Lead researcher Christina Ambros-Rudolph in a published report said she and her colleagues referred almost twice as many marathon runners as nonrunners to local dermatologists for skin lesions. And this was despite the control group having a higher sun sensitivity than the athletic one.
So cover up when running outdoors (which is easy enough if you live where it’s cold right now) and wear waterproof sunscreen on exposed areas, regardless of the climate. When it does turn warm enough to shed those layers, try to avoid running when the sun is strongest. It’s sound advice, and that’s no hoax.