It seems that you can't head to a gym or run down your favorite trail these days without finding someone wearing compression garments. Weekend warriors and elite athletes alike are squeezing themselves into knee-high socks, tights and even full bodysuits that promise to improve performance and speed recovery from hard workouts.
Those claims might be true. Or they might not be. A good bit of research has been conducted on the effectiveness of compression gear, and the results are inconclusive.
Two Indiana University studies released in 2010, for example, found no impact on running performance when highly trained distance runners were outfitted with lower-leg "sleeves," and no effect on jumping ability when 25 average guys wore upper-leg compression garments in three different sizes.
Yet Canadian researchers concluded in a 2012 study that compression socks improved blood flow to calves and "may enhance performance, especially in sports that require repeated short bouts of exercise."
As for recovery, the evidence is somewhat more in favor of compression. Australian researchers who put rugby players in waist-to-ankle tights during "active recovery" runs on a treadmill (what you and I would call a cool-down period) discovered that compression helped remove lactate from their blood. Lactate is the byproduct that causes your muscles to burn during intense exercise.
And University of Connecticut researchers who put men and women in "whole body compression garments" after intense weightlifting found that they helped reduce fatigue, swelling, muscle soreness and other side effects of exercise.
How to make sense of all this?
"The bottom line: For runners who buy four pairs of $120 shoes at a time, invest in compression garments for recovery -- they won't hurt," Pete McCall, exercise physiologist for the nonprofit American Council on Exercise, told me in an email. "If budget is a concern, take a cold bath and use ice for recovery. It will be more cost-effective."
We all know that fitness fads come and go. Competitive athletes are constantly looking for an edge, and the rest of us are certainly willing to try new shortcuts and techniques if they're safe and effective. Remember those toning shoes that produced a $1.1 billion market in 2010 before the Federal Trade Commission forced Reebok and Skechers to pay tens of millions of dollars each for false claims in their advertising?
But it's equally fair to conclude that we in the real world might be out ahead of the scientists as we search for new, different and better. As I wrote last year, pregnant women have been strength training for a while now, despite a dearth of formal research to determine whether it's safe.
So, absent any serious conflicting evidence, I'm inclined to believe Alyssa Smith, a 39-year-old recreational runner from Gaithersburg, Md., who swears by her CW-X compression pants, which have panels sown into certain spots, such as the knee joints, where extra support is helpful during and after a run. Support -- and the idea that the garment helps return blood to tissues more quickly, bringing them oxygen and flushing out lactate and other byproducts -- are the main concepts behind compression. The socks have been used for decades by travelers on long plane rides to prevent blood clots.
During a long run, the tights hold Smith's back and hips tightly and help keep her knees aligned as she fatigues, she said. After long runs -- Smith runs 30 to 35 miles a week -- she now wears them instead of taking an ice bath, which she never liked, to reduce inflammation and swelling.
"I almost feel that it does what an ice bath does, but [it's] not as cold," she said. "The tights you can wear all day and sleep in them at night." (Ice baths, by the way, are not grounded in good research, either, according to Kenneth L. Knight, a professor of athletic training at Brigham Young University who has spent his career studying cryotherapy for athletes. But many athletes love them.)
Under Armour, the athletic apparel behemoth based in Baltimore, sprang more or less from founder Kevin Plank's belief in the value of compression. Tight-fitting "base layers," as Under Armour calls them, reduce injury and enhance performance by wrapping muscles more tightly against the skeleton, even as they wick away sweat to keep athletes cooler and drier, said Glenn Silbert, vice president of men's, youth and accessories.
"There is good science behind it," he said. The company doesn't release sales figures, but compression gear continues to be a fast-growing part of the business, he said. According to the Sports and Fitness Industry Association, Americans bought about $930 million worth of compression gear and similar garments in 2011, up 5 percent from 2010.
One last, fascinating thought about compression garments: At least one researcher has found a placebo effect when it comes to recovery. That is, athletes recovered better in them because they believed they would.
In July, Rob Aughey, a senior lecturer in sport physiology at Victoria University's School of Sport and Exercise Science in Australia, told the website News. com. au: "When testing CGs in elite athletes, we found that wearing them did result in an improvement in the perception of pain and fatigue for the athlete. However, we found no evidence to suggest that the garments can help improve the actual rate of physical recovery."