Unfortunately, we weren't all smiles the next day when we found ourselves sporting some light sunburns. We'd applied sunscreen prior to the event, but proper prevention takes more than slapping on an ounce of the stuff just before hitting the road. Let's demystify how to make your sunscreen work best for you.
When choosing an SPF rating, know that this number represents how long you can stay in the sun without expecting a burn — but it varies per individual. The formula is to take how many minutes you can normally be outside without getting a sunburn and multiply it by the SPF rating. Someone who burns after only 15 minutes on a cloudless day could absorb 50 times as much solar energy with an SPF 50 sunscreen.
But sunscreen doesn't take effect immediately, nor does it last indefinitely. It takes time for the skin to absorb sunscreen — it needs to be applied at least 30 minutes prior to initial exposure. And sweat can cause its effectiveness to deteriorate, requiring reapplication every hour or two. (On the walk itself, the midday change of clothes bag you're provided is a great place to store your sunscreen for later reuse.)
The latest issue of Reader's Digest has additional sunscreen tips, including the counterintuitive suggestion to avoid sunscreen lotions with a rating higher than 50 SPF. Take these facts under advisement when protecting yourself during your training this summer!