14 DAY TRIAL // Marathon runners have increased chances of developing skin cancer due to the fact that they are exposed to sun rays while running long distances and their immune system may be weakened by strenuous physical effort, reports a new study carried out by a team of scientists at the Medical University of Graz in Austria. Writing in the Archives of Dermatology Journal, Austrian researchers explained that marathon runners presented a larger number of atypical moles and liver 'spots' than their counterparts of the same age and sex who did not practice the sport.
The presence of more liver lesions also known as solar lentigines and more abnormal moles in marathon runners was associated by scientists with a highly increased risk of developing both non-malignant and malignant melanoma skin cancer. Researchers also pointed out that marathon runners who usually train at the highest physical activity levels are the most likely to become afflicted by the non-melanoma or melanoma skin cancer.
The team of scientists explained that excessive exercising leads to immunosuppression: "This is quite well established. Many alterations in immune cell function have been noted at the cellular level in marathon runners. For example, there is the association between excessive exercise and immunosuppression reflected in the increased incidence and severity of upper respiratory tract infections in marathon runners after races."
High-intensity trainings on sunny days increase the risk of developing skin cancer because sweating causes the skin to become highly more sensitive to solar UV radiation. This increased sensitivity of the skin to solar radiation when sweat is present makes individuals who work out on sunny days, marathon runners for instance, more prone to sunburn and increase the rate of UV absorption into the skin.
The current study was conducted on 210 both male and female marathon runners and 210 other individuals of the same age and sex as the performance runners. Overall results showed that subjects in the marathon group presented a large number of risk-indicators for skin cancer, which include abnormal moles and more liver lesions. Also, the investigation revealed that only 56% of these subjects reported using sunscreen on a regular basis, even if exposure to UV radiation emitted by sun rays is commonly known to be the major risk-factor for skin cancer.
"They should reduce UV (ultraviolet radiation) exposure during exercising by choosing training and competition schedules with low sun exposure, wearing adequate clothing, and regularly using water-resistant sunscreens. Sunscreen alone is not the ultimate answer. It's also important to wear reasonable gear that covers the shoulders and upper back, and to avoid training in peak sun hours," advised in their report leader of the research Dr. Christina Ambros-Rudolph and colleagues at the Medical University of Graz.