Best worst choice: unintentional tanning

The gist:

Training outdoors subjects you to UV rays, which almost immediately cause DNA damage that can lead to skin cancer, wrinkles, and sun spots. SPF is the obvious line of defense, but you can also minimize the effects with post-exposure strategies.

Expert insight:

Once you’re back inside, load up on antioxidants, which fight free radicals (which are triggered by UV radiation in sunlight) before they can do harm, says Chicago-based dermatologist Jordan Carqueville, MD. There are a few ways you can do this.

The first is by using a topical vitamin C serum on your face for more even skin tone in the short and long term. The second is by eating antioxidant-rich foods, like carrots or sweet potatoes for beta-carotene and almonds or greens for vitamin E. You should do this regularly for a steady supply, but especially on days you’re spending time outdoors.  

The bottom line:

If nothing else, use a sunscreen with an SPF of 30 or higher anytime you’re outside for more than five minutes, re-applying every hour, Carqueville says. Look for one with a chemical-mineral ingredient blend and UVA and UVB blockers. EltaMD UV Clear fits the bill.