Do you get your stress out by working up a sweat?

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Beauty isn't skin deep, even when it comes to the beauty of your skin. Fluctuating levels of hormones are the reason our skin hits a decidedly rough patch in our adolescent years. But no matter how old you are, stress hormones (such as androgen and cortisol), the sun's UV rays and your lifestyle all affect the appearance of your skin.

Your skin is your largest organ, and it's easy to take it for granted. For one thing, it doesn't appear to be doing much. This isn't true, though -- your skin is constantly working on your behalf. It protects you from microscopic invaders such as viruses and bacteria, keeps moisture out and keeps every other part of you in. That's no small order for a layer of tissue that is -- at its thinnest point, on your eyelids -- just half a millimeter thick. Not only that, but your skin is constantly replacing itself, producing new skin cells that migrate outward toward the surface. It is during this migration that skin cells can clog pores, leading to acne.

Most of us have to deal with acne at some point in our lives, and many of us deal with it off and on throughout. Infants get it, teenagers are cursed with it, and it even strikes adults. And that's not all that's happening to your skin as you age -- skin gains wrinkles, creases, and shows its wear and tear. It loses its once youthful glow, loosens, takes on a grayish hue and develops discolored spots.

Every organ in your body is affected to some degree by aging, stress, and the introduction of unwelcome substances. Exercise, however, has been shown to slow, stop or even reverse many of the signs of these conditions.

As great as staying in shape is, one of the primary reasons we huff it and puff it at the gym or on the track is to look good. So why does exercise seem to make some people's skin break out?

Stop! Don't throw away your workout gear before reading the next page.