Your Complete Guide to Compression Clothing

Companies claim compression clothing make you run faster, jump higher, and recover better after exercise. But do they really work? 

"The theory is that compression on top of the skin and underlying muscle will have a positive effect on increasing the movement of oxygen in the blood, thus enhancing your performance," says Michele Olson, Ph.D., professor of exercise science at Auburn University Montgomery. Oxygen is an essential component of your workout performance—during exercise, your muscles are working harder; therefore, they need more oxygen to fuel the cellular respiration process which gives you energy. It's the reason you're sucking in air at a faster rate during your run. That oxygen is carried by your blood to your muscles, which convert it into energy. So good blood flow is pretty important.

And compression clothing really does increase blood flow. In fact, doctors have been using it for years in patients with poor leg circulation and varicose veins. "The tight socks help blood vessels to constrict and return the blood up toward the heart instead of that blood pooling in the legs, creating swelling and hampering blood flow to the muscles and organs in the rest of the body," says Olson.

Apply that same idea to athletic wear and you should see the same results, right? At best, the research on compression clothing's effect on performance is mixed, says Olson. A review of studies on several types of compression concluded that there are no scientific indications regarding the benefit of compression garments in competitive sports. Still, some studies have seen a slight improvement in jumping performance.

Probably the best effect of compression clothing is actually during recovery. "Because compression restricts blood vessels, it can cut down on swelling, which stiffens the muscles and joints, making it harder to work out the next day," says Olson. Plus, since your muscles experience micro-tears during hard workouts, causing inflammation, having the support of compression clothing can reduce delayed-onset muscle soreness.

So really, you're better off donning compression clothing after your workout to speed up recovery and decrease soreness.

If you're already a fan of wearing compression-fit clothing during your workouts, this doesn't mean you need to stop, especially if you feel that it really does make you run faster or squeeze in a few more reps. "The few studies that have found positive changes in performance due to compression were actually correlated to the placebo effect," says Olson.

Whether you're looking for compression clothing to wear during or after your workout, here are the best options.

American marathoner and Olympic silver medalist Meb Keflezighi famously won the 2014 Boston Marathon while wearing a pair of white CEP compression socks. Originally designed for medical use, tight toe-holders improve circulation and oxygen delivery to your muscles, stabilize your calves, support and warm your Achilles tendons, and reduce foot and muscle fatigue, all of which might add up to improved performance. Does it work? Studies are mixed when it comes to speed, but research suggests that compression socks might reduce post-workout muscle soreness.

To maximize the potential benefits, look for a stocking that's graduated—tighter at the ankle and looser toward the knee—and one that offers sizing specific to your gender and calf-size, like the Zoot Women’s Ultra 2.0 CRx Sock. Socks come in different grades of compression, from 15 to 20mmHg (a measure of pressure) on the lighter end to 20 to 30mmHg on the tighter side.

As mentioned previously, compression clothing works its wonders after your sweat sesh. Slip on graduated recovery socks or tights in the 24 hours after a tough run—like CEP Compression Socks for Recovery. Many recovery socks have a lower grade of compression than their active counterparts. Putting the pinch on your calves may reduce soreness and repair muscle damage for up to three days later. (Related: 8 Unconventional Ways to Treat Sore Muscles)

Since lower leg squeeze—not foot force—matters most, some runners prefer compression sleeves so they can still wear their favorite socks. Like stockings, be sure to buy sleeves that fit the circumference of your calf for the best results. Thirty 48 Graduated Calf Compression Sleeves come in two different grades of graduated compression to increase circulation and stabilize muscles for training and recovery.

Compression tights promise the same benefits as socks: better blood flow, muscle support, reduced fatigue and faster recovery. With a full gam grip, they mimic medical stockings. Like socks, be sure to wear tights with graduated compression from ankle to thigh or you won't reap the benefits of improved circulation to deliver oxygen to your muscles. The compression clothing tights should be sufficiently difficult to pull on. C3fit Women's Performance Long Tights fit the bill with graduated compression, vibrant designs, and fabric that shields you from ultraviolet rays. (Related: Smart SPF Products That Aren't Sunscreen)

Compression shorts target upper leg muscles the way socks target calves to reduce fatigue and soreness. 2XU Women's Elite Compression Short uses a blend of fabric panels to provide different levels of support and alignment to varying muscle groups. Glutes and hammys get a heavier fabric, while abductors and quads get a more flexible stretch. Research suggests that lower leg compression is the most effective at improving blood flow, but that doesn't stop runners from trying to maximize the potential benefits of all-over compression. (Related: Why post-workout muscle soreness hits people at different times.)

Like their leg counterparts, arm sleeves use the power of compression clothing to improve circulation and speed recovery by reducing muscle vibrations, in addition to adding warmth (just this winter workout gear). The Zensah Compression Arm Sleeves use graduated compression and pinpoint compression at the elbow.

Compression shirts aim to cinch your upper body, reducing muscle fatigue in tight arms, shoulders, and hard-charging abs. Do they work? The jury is still out. See for yourself with the 2XU Women's Long Sleeve Compression Top, which has graduated compression through the arms and back.