Compression socks: performance enhancement or nerd alert?

Women's world marathon record holder Paula Radcliffe and another runner
both wear compression socks as they lead the New York City Marathon.
Photo from Eric via Flickr

A few years ago compression socks were for grandma's circulation problems and catholic schoolgirls. Now they are the hot new triathlon (and running) trend, and an even hotter topic for debate. Do compression socks and compression tights improve performance, or are they only for recovery? Should you wear them while you're running or after your run? When WTC tried banning compression socks in Kona (because they would cover competitors' ages on their calves), people were outraged and WTC quickly rescinded. But the triathlon world is still in a tizzy about compression socks, pitting those who insist they improve running performance against those who point out that there is no proof that compression gear during competition provides any performance benefit. The latter group throws around curses like "placebo" and "fad."  But what do the experts say?

Compression socks and recovery

In the realm of recovery, compression gear has a documented benefit for endurance athletes. Graduated compression socks and stockings provide the most squeeze at a runner's ankles, with compression tapering off toward the top. This keeps blood from pooling in the calves and ankles, which is why they're great for Granny's kankles. If blood is not getting stuck in the ankles, new blood can be pumped in to the extremities to remove harmful biproducts of exercise and repair damaged tissue, reducing delayed onset muscle soreness and enhancing recovery. A study at the Institute of Food, Nutrition and Human Health, Massey University, Auckland, New Zealand found that compression socks provided no performance benefit over a 10K run, but that compression socks reduced post-workout soreness. If an athlete is able to recover more effectively from her workouts, she will be able to include more high-quality sessions over the course of the season, making her faster. Based on this information, compression gear undoubtedly enhances performance when used after a workout for recovery.

Yvonne van Vlerken, obviously not concerned with fashion
wears compression socks and a swim suit in the Xterra
Makena Beach 10km Trail Run.
Photo courtesy Thomas Vonach and Endurance Team

Run in compression socks, or recover in them?

The debate begins when athletes squeeze into their compression socks before they have done anything to recover from. Compression enthusiasts believe that by wearing compression socks while they run, they improve circulation in the lower legs (remember the kankles), providing more blood to the working muscles and improving performance. The problem is that there is no scientific evidence to support this theory. A study by the Institute of Medical Physics in Nümberg, Germany found that performance at aerobic and lactate threshold were significantly increased by compression tights in treadmill running tests. "However," researchers puzzled, "the underlying mechanism was only partially explained by a slightly higher aerobic capacity." In other words, when the athletes ran faster in their compression tights, it couldn't be sufficiently explained by more efficient circulation. Something else was at play here, and this is where things get even less concrete.

Muscle jiggle?

Anecdotal evidence has suggested that perhaps it is the reduced muscle movement while wearing compression socks that enhances performance. "I also believe [calf-length compression socks] help with my knee discomfort during long runs. If I go without the compression tights my knee usually blows up at mile 7-8. If I go with I get no pain. I don't think they make me faster but they do make my runs more comfortable," says a poster who calls himself inaba116 on a Slowtwitch forum about compression socks. Matt Fitzgerald provides a different theory as to why compression tights and socks might provide an advantage. Fitzgerald cites a biomechanics expert at the University of Calgary, Benno Nigg who believes that muscles prefer to vibrate at a certain frequency upon impact with the ground, and runners unconsciously vary their stride to hit this frequency, selecting a less efficient stride to hit an ideal vibration frequency. Variables such as shoes, road surface, and other factors can all affect the reverberations through the muscle from ground impact, and compression socks can dampen the magnitude of these vibrations. In theory, this could allow a runner to maintain a more efficient stride with compression gear on  than without.

Shaking and jostling may also increase muscle damage and soreness after a long run. "Compression socks hold the muscles together so to speak, minimizing the vibrations and contractions so you won't be as sore afterward and you can return to running faster, which in turn, improves performance," says John Smith, assistant professor of kinesiology at Texas A&M. If this is true, it gives credence to the theory that wearing compression gear during your run may actually enhance recovery before you actually begin recovering.

Placebo effect

Never underestimate the placebo effect. Real performance gains are made from fake means every day. In the past couple of years, nearly all the competitors in Kona have been wearing the dorky socks, providing an extra sense of security when they go out and hammer. Paula Radcliffe has been running in compression socks for years now while battling lower leg injuries. "It feels like your calf is getting a little massage," says Smith. "I liked the compression, as well, but whether the socks made me run faster I cannot say," said Fitzgerald of his own trial with compression socks. "You can’t always feel a 1 or 2 percent enhancement in performance." So who cares if the emperor has no clothes? If compression socks are your security blanket that lets you go out there and give it your all, wear your knee socks and running shorts with pride. However, remember that to those who are not familiar with the latest triathlon fads, you will look like a bit of a boob.