An Athlete's Guide to Summer Workout Safety

Erase Acne

Exercise increases circulation, which can keep skin clear. But for women, running so much that it interferes with your period (amenorrhea) can trigger acne, explains Dr. Hale, because the hormonal balance shifts (more of the male hormone androgen, less estrogen). And for many runners, male and female, acne happens when bacteria naturally present on the skin gets trapped in pores by sebum and sweat. Folliculitis, another form of acne, is caused by the same combo that in this case infects hair follicles, causing a crop of red bumps.

Protect yourself: Even though a 2008 Pediatric Dermatology study of adult male exercisers showed that showering within an hour after a sweat-drenching workout (as opposed to waiting several hours) made little difference in the existence of body acne, it still makes logical sense to keep skin clean. "If you're unable to wash right away, use wipes, or at least change clothes," says Dr. Hale.

More: Beauty on the Go

Confront Chafing

It's your old friend friction again; skin rubbing on skin, or coming in contact with loose or ill-fitting clothing, can lead to rashes and even infection, says Dr. Hale. Chafing is most common under upper arms, beneath breasts, between thighs, or (for men) on nipples. Moisture, from sweat or a rain-soaked run, just makes it worse.

Protect yourself: Anti-chafing sticks or simple petroleum jelly provide a protective barrier. Be sure clothing fits snugly but doesn't dig into your skin; is made of a wicking material; and doesn't have irritating seams. Postchafing, use Aquaphor or petroleum jelly to protect and soothe.

More: Try Olive Oil or Lycra to Stop Painful Chafing

Tool Kit

Avoid skin emergencies with the right gear.

1. Snug socks
   Injinji Performance Series Lightweight Toesocks ($10)
2. Sweatproof sunscreen
   Coppertone Sport Pro Series Sunscreen with DuraFlex ($11)
3. Portable wipes
   Neutrogena Oil-Free Cleansing Wipes Pink Grapefruit ($7.50)
4. Anti-chafing salve
   Eucerin Aquaphor Healing Ointment ($8.50 for 3.5 oz jar)
5. Blister aid
   Mission Athletecare Blister Armour Anti-Friction Stick ($8)

More: How to Adapt to the Heat for Summer Runs

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