Canadian runners are enjoying their first sunny, hot running days of the season. That means it’s time for sunscreen. There are many kinds, but runners have special needs when it comes to choosing specific products, since we spend a great deal of time outdoors in summer. Just don’t assume that covering up with your clothes will protect you from UVA and UVB rays; some materials block some rays, but most do not. Also, remember that most sunscreen lotions are only effective for a couple of hours, so on a longer run, you will have to re-apply to keep protected, since we know that the risk of many skin cancers increases with repeated sunburns.
Water- and sweat-resistant sunscreens are essential to keep you protected when you’re sweating. All sunscreens eventually wash off in the water or from sweat, so don’t be fooled by so-called offers of waterproof sunscreen–and if you’re swimming, it’s always smart to re-apply when you get out of the water.
The limits of SPF ratings
A high SPF (sun protection factor) protects you more, with the caveat that the higher the SPF, the less protection each SPF point provides. The points are measured by how much solar energy (UV radiation) is required to burn you while wearing the sunscreen. SPF 2 filters about about 70 per cent of UVB rays. SPF 50, likely the highest effective SPF rating, filters out about 98 per cent of UVB rays. The catch is that SPF only reflects protection against UVB rays, and UVA rays are also dangerous to our skin and need to be filtered, so buy a broad spectrum sunscreen that protects from both.
Protect your skin even when it’s cloudy
With skin cancer rates on the rise, it’s important to make sure you’re avoiding overexposure to the sun. Use sunscreen in summer, even when it’s overcast. Don’t assume that your clothes will protect you from both UVB and UVA rays, since not all running clothes do, but do wear a hat and sunglasses. A 2011 study of white adults in the United States found that the best way to avoid sunburn while outside is simply to regularly find shade. Also, it’s best to schedule your runs either before 11 a.m. or after 2 p.m., when the sun’s rays are strongest. Choose a mineral sunscreen, since this type contains safer ingredients like zinc oxide or titanium dioxide than regular sunscreen and does not require you to wait 15 minutes before it’s effective.
Take a broad approach when thinking about sunlight protection during the summer. Think about clothing that blocks UVA and UVB, wear a hat and plan your running routes through areas with more shade.