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As the various brands of compression gear compete to distinguish themselves, one of the claims you hear a lot (I’m looking at you, CEP) is that you need “medical grade” compression to achieve true performance benefits. Seems reasonable. So let’s test it…
Australian researchers just published a new study in the International Journal of Sports Physiology and Performance, looking at the effect of wearing Skins tights on endurance running performance. The twist: their subjects (11 well-trained distance runners) did three sets of testing, once in loose shorts, once in the “right” size of Skins leggings, and once in a set a Skins leggings one size too small (to get extra compression). The correct size produced an average of 19.2 mmHg pressure gradient across the calf, while the smaller size produced 21.7 mmHg. For comparison, CEP’s socks promise a max of 22-24 mmHg at the ankle, with 18-20 mmHg on the calf.
The researchers tested pretty much every parameter they could think of, and then some. The performance parameters were simple: a progressive VO2max test, and a time-to-exhaustion test at 90% of VO2max. The physiology measures included heart rate, blood lactate, expired gases, and near-infrared spectroscopy of the leg muscles to measure how much oxygen-carrying hemoglobin and non-oxygen-carrying hemoglobin was passing by in the blood.
The results: in a nutshell, actual running performance was unchanged in any way. Compression tights didn’t make the runners run faster, and there was no difference between the two levels of compression. Repeat:
No improvement in endurance running performance was observed in either compression condition.
But… they measured all these lovely physiological parameters. And sure enough, after sifting through all of them, it turns out that they weren’t all identical. At low speeds, compression garments seemed to increase muscle blood flow; at high speeds they increased non-oxygen-carrying hemoglobin in the vastus medialis; etc. etc. The picture is pretty messy, but the message is still clear:
However, the magnitude of this improved venous flow through peripheral muscles appears trivial for athletes and coaches, as it did not improve [time-to-exhaustion] performance. This would suggest that any improvement in the clearance of waste products is insufficient to negate the development of fatigue.
But all is not lost for compression fans:
However, the data presented may have helped to identify and support the responsible mechanisms that relate to the postexercise recovery improvements associated with wearing [lower-body compression garments].
Note that this study didn’t actually find anything involving improved recovery. It just found that if you squeeze a limb, blood flow through that limb changes. That might result in improved recovery (and indeed some other studies do suggest that’s the case), or it might not. But the idea that compression will help you run faster is seeming less and less plausible.
Any mention in the study about muscle vibration reduction due to wearing compression, and if that actually increases time to fatigue? Aside from increased blood flow, you often hear this claim from compression brands.
While you’re correct in stating that “this study didn’t actually find anything involving improved recovery”, the study never set out to examine parameters in recovery; rather their focus was on whether compression garments improve performance during (high intensity) running. Apparently, they don’t.
However in their discussion, they do comment on increased venous flow in the vastus lateralis, and suggest that this improved venous flow “strengthens the suggestion that wearing CG improves postexercise recovery. Further research should determine whether this improved venous flow is responsible for improving recovery”.
I’m not an advocate for compression tights. I tend towards skeptic. But I also tend to specificity – while their research was on performance, not recovery, they do point to peripheral evidence that suggests that compression garments worn during recovery may have some benefit. As always, further research is needed…
@Ken: No, they didn’t discuss muscle vibration. However, they measured time-to-fatigue and didn’t see any improvement, so — in this configuration and under these conditions, at least — it didn’t appear to make a difference to fatigue.
@Timiji: My point was that the extrapolation from “seeing a difference in some physiological variable” to “seeing a physical difference” is a very big leap. Tons of previous studies have seen physiological changes (it’s pretty much inevitable that circulation changes when you squeeze the leg!), but actual differences in useful physical outcomes have proven to be much more elusive. You’re right that they didn’t set out to study recovery — and as a result, the study design doesn’t tell us anything useful about recovery.
Here’s an anecdotal experience for you: I am a woman with large, muscular thighs and rear end. I run distances up to 13 miles among other things like plyometrics, etc. that are high impact. My body fat is at approximately 18-19%. It HURTS when I run or do plyo WITHOUT compression pants AND shorts layered on top for extra hold! Seriously, my muscle and flesh tug and bounce and it HURTS! I do not have the typical “runner’s build” of skinny legs and ultra-low body fat, but the body of a natural body builder! In addition to pain, running without compression gear feels awkward and slow. I would like to see what body type the people in this study had- if they were all toothpicks with ultra-low body fat and little muscle, I can see why it had no impact. For athletes like me however, it DEFINITELY makes a HUGE difference in my performance and comfort!