For many people, taking part in activities such as hiking, climbing, tennis, golf, cricket swimming etc. this means being outdoors for long periods of time and puts them at risk of long periods of exposure to UVA and UVB rays that can cause the progressive skin damage that leads to cancer.
Skin cancer is the most common type of cancer and although most people develop the less harmful basal cell or squamous cell variety, the incidence of melanoma is rising, especially among young people, and it can be deadly.
The best way to prevent skin cancer is to stay out of the sun, but if you play a sport there's little chance of that.
If you are going to spend a lot of time outdoors playing, you need to wear sunscreen, which protects your skin by absorbing or reflecting the sun's rays. However, not just any sunscreen will do.
A problem in pro tennis
A recent feature by the Wall Street Journal found that of all the accessories that professional tennis players have at their disposal, sunscreen may be their least favourite as it can mix with sweat and run into their eyes, and also affect their grip on the racket.
As such, some don't wear it at all. Some apply it before daytime matches, but the overall consensus is that it is not ideal.
Particularly at events such as the Australian or US Open, where high temperatures and humidity are typical, the heat mixes with sunscreen, and the sweat can form a gooey substance affecting both their vision and their grip.
Some say they have spent years shuffling through various sweat-resistant sports sunscreens, searching for one that doesn't sting their eyes.
The WSJ piece cites Cara Black, a doubles player from Zimbabwe, who says she uses a zinc cream and Ukraine's Olga Savchuk, who says that the one lotion that doesn't bother her is available only in Japan and South Korea, so Japanese pro Kimiko Date-Krumm buys it for her.
Others, such as Jamie Hampton says the key to applying sunscreen before playing tennis is not putting it on your forehead.
Darrell Rigel, a clinical professor of dermatology at New York University, says he has treated both pro and amateur tennis players and encountered similar resistance to using sunscreen.