Research finds that compression expedites recovery for marathoners.

At 40 and still competing at the top level, Meb Keflezighi remains the most dominant American marathoner in history. The 2004 Olympic silver medalist in the marathon won the 2009 New York City Marathon and the 2014 Boston Marathon and is the only American to win both big city marathons and an Olympic medal.

His longevity as an elite runner has been aided by his balanced training regimen, which incorporates core-strengthening and cross-training, along with a strict diet. But it’s also been helped by his penchant for wearing compression socks.

Like Olympic bronze medalist Shalane Flanagan and Chris Solinksy, the first American to run a sub-27 minute 10K, Meb wears compression socks not only for recovery but during his key races.

Recent research suggests that compression socks clearly enhance your recovery from hard workouts and races, allowing you to return to running sooner, which provides you with a competitive training advantage.

A study published in February of this year in the Journal of Strength and Conditioning Research by a group of Australian and New Zealand scientists offers some of the clearest evidence. It examined 33 runners, some of whom wore below-knee compression socks for 48 hours after a marathon, and found that those who recovered with compression socks were able to run on average significantly longer on a graded treadmill test 14 days after their marathon than the control group that didn’t wear compression socks.

“In the compression group, average treadmill run to exhaustion time two weeks after the marathon increased by 2.6 percent,” the researchers reported in their study. “In the placebo group, run to exhaustion time decreased by 3.4 percent. This shows a significant beneficial effect of compression socks on recovery.”

A review of 12 other studies on compression socks published in the British Journal of Sports Medicine last year reached a similar conclusion about the recovery benefits of compression. It concluded that compression garments had a “moderate” effect in reducing delayed onset muscle soreness after tough workouts and allowed damaged muscle tissue to regain its power and strength. “These results indicate that compression garments are effective in enhancing recovery from muscle damage,” the researchers said in their study.

Originally developed to improve blood circulation and prevent blood clots in people with deep vein thrombosis and other problems, compression socks squeeze the blood that normally pools in your feet when you’re sitting or standing and helps send it up toward your heart. There, the blood is re-oxygenated by your lungs and then sent back down to more quickly to repair the muscle damage in your legs.

When you’re running, contractions from the muscles in your legs act like a pump to send the blood that would otherwise pool in your lower legs through your circulatory system. That may be why most researchers who’ve studied the issue have not yet found a performance benefit from running with compression socks.

Nevertheless, it’s clear that compression socks, calf sleeves, shorts and tops can keep your muscles warm and improve blood flow during runs on cold days. Compression socks provide an extra bit of stability for your ankles and calves when you’re running on an uneven trail. And the spandex-like fabrics in compression garments allow your body to efficiently wick sweat away, which can prevent chafing and blisters when you’re hot and sweaty.

However you decide to use them—whether for running or to recover more quickly from your hard runs or races—make sure your compression socks fit properly. The best manufacturers sell socks fitted specifically to your left and right feet and require you to measure the diameter of your calves to get a properly fitted pair. Also make sure the compression sock or calf sleeve you purchase is graduated—tighter at the ankle than at the top of the calf to promote venous blood return and has 20-30 mmHg of moderate compression, which is considered ideal for performance and recovery.

Shop medical-grade CEP Compression socks.