Turns out all those lotions and potions in your medicine cabinet aren't the only way to keep your skin youthful. Results from a study conducted at McMaster University in Ontario found that people who exercised for at least three hours per week had noticeably younger skin than people who were sedentary and exercised for less than an hour per week, regardless of their age.

"Under a microscope, the skin of those who exercised regularly appeared 20 years younger," explains dermatologist Nava Greenfield, M.D., of the Schweiger Dermatology Group in New York City. While the exact connection wasn't completely clear, the exercisers had notably higher levels of a myokine called IL-15 in their skin, a substance created by working muscles that can jumpstart changes in cells, even those cells that aren't near the muscle. So, on those days when you need a little more motivation to get your booty off the couch and into the gym, remember that exercise is a proven way to ward off wrinkles.

Image via Getty

Since you now know that exercise may help keep you looking baby-faced, the last thing you want to do is counteract those amazing anti-aging effects with too much sun exposure: "Sun exposure during outdoor exercise will lead to faster aging and higher risk of skin cancer," says Greenfield. And while slathering up with a sunscreen is a must (duh), "You need to be extra careful about reapplying, since sweating makes it even harder for sunscreens to stay on," cautions Peter Lio M.D., clinical assistant professor of dermatology at Northwestern University. Choosing a waterproof, sweatproof option is obviously best; try the new Shiseido Sports BB Broad Spectrum SPF50+ With WetForce Technology, $38, which has the added benefit of a slight tint. Still, even those formulas can slide off with excess sweat, says Greenfield, who suggests pairing that with UPF clothing and a wide-brimmed hat for extra protection.

Image via Getty

A good workout increases blood flow throughout your body, including your skin. Increased blood flow enhances oxygen delivery and removes waste from skin cells, says Lio, leaving your skin healthier, plumper and extra glowy. It's the same principle behind oxygen facials and microdermabrasion treatments that are meant to stimulate circulation, so if you can't book a spa appointment, consider booking a workout class instead.

Image via Getty

Exercise is a proven stress-reducer, and those benefits extend far beyond the mental. Stress triggers the adrenal gland to produce excess amounts of cortisol -- aptly dubbed the stress hormone -- which causes inflammation throughout the body. In the skin, this exacerbates inflammatory conditions such as eczema, psoriasis and even acne. "Exercise reduces cortisol levels, so regular exercise can improve those conditions by reducing the body's response to stress," explains Greenfield. The bottom line: Hit the gym when you want to calm your mind and your skin.

Image via Getty

When it comes to acne, exercise can be a bit of a double-edged sword. As mentioned, it reduces cortisol (which increases both oil production and inflammation, two key components of acne), but sweat can clog your pores and lead to breakouts. There's even a condition known as helmet acne, where you get pimples along the forehead from wearing a helmet while biking or playing sports, notes Lio. Happily, you can stay acne-free simply by cleansing your skin immediately post-workout. We totally get that sometimes there's just no time to wash your face after spin class, but there's always time for a face wipe. Choose ones with glycolic or salicylic acid, which will wipe away the acne-producing components of sweat and keep your skin clear, says Greenfield. Our pick: Garnier SkinActive Clean + Purifying Oil-Free Cleansing Towelettes, $5.99. And don't forget the skin below your chin. If you can't get out of your sweaty tank and sports bra right away, wipe down your back and chest to avoid unsightly blemishes from popping up on your bod, too.

Image via Getty