Sun exposure behind runners' skin cancer risk says study
Marathon runners may face a higher than normal risk of skin cancer, Austrian researchers have found, most likely due to intense exposure to direct sunlight.
The University of Graz study compared 210 marathon runners against 210 non-runners, finding that the runners were more likely to have potentially pre-cancerous growths.
The growths - known as atypical moles, which are larger than usual with poorly defined borders and liver spots, or solar lentigines - are recognized skin cancer risk factors.
These were particularly common among runners who trained at the highest degrees of intensity and were likely due to high exposure to damaging UV rays in sunshine.
"Intense but infrequent exposure to UV radiation from the sun poses the greatest risk for melanoma skin cancer," said Ed Yong of Cancer Research UK.
"These are exactly the type of exposures that marathon runners get during training or competitions. This explains why they might be likely to develop unusual moles which could indicate a higher risk of skin cancer.
"This study highlights the need for marathon runners to protect themselves from overexposure to the sun.
"If you are a runner, try to schedule your training outside of the midday period when the sun is at its strongest. Remember to wear adequate clothing, and regularly apply SPF 15+ sunscreen, as it may come off with sweat or be rubbed off by your clothes."
Only 56 per cent of the runners involved in the study said that they regularly used sunscreen. The study is published in the journal the Archives of Dermatology.