COMPRESSION WEAR
Key to improving performances is faster recovery between sessions. Cue compression wear - aka, the most divisive product in our sport
Scan the Ironman and ITU circuits and it’s commonplace to see an elite athlete dressed in what some call ‘contraception socks’. It’s the same for age-group triathletes around the world. Yes, they might resemble football socks from lost property, but that tight fit is vital to enjoy the mooted benefits of compression wear.
“Size is important to ensure a graduated level of compression at the optimum levels to assist circulation,” explains Mike Martin, UK director of compression specialists 2XU. “Many products are sold as ‘compression’ but aren’t graduated or provide an insufficient squeeze to promote bloodflow or reduce muscle movement.”
Graduated? Squeeze? What’s Martin on about? Let us explain. Every time you move, your calf muscle squeezes the veins of the lower limb to send blood back up to the heart and other major organs. If you’ve exercised, this blood contains toxins like free radicals that can inhibit recovery. These toxins are removed in the kidneys, so the more efficiently blood can be pumped back up the body, the faster you’ll recover. In theory, compression socks provide graduated pressure – greater at the ankle, mildly less so at the calf – to act like a second pump, accelerating this process.
“Compression is measured in millimetres of mercury (mmHg), a unit of pressure more commonly applied to blood pressure,” says Dr Akbar de Medici of independent outfit Compression Advisory. “A normal resting blood pressure is 120/80mmHg. The first figure is pressure of blood away from the heart; the second figure is pressure
of blood back to the heart.” Research has shown that femoral (thigh) bloodflow increases to 138% of the norm when the sock achieves a compression rate of 18mmHg at the ankle and 8mmHg at the calf.
And pressure is key. In the medical world, where they were first developed around 60 years ago to prevent pulmonary embolisms before the likes of Skins spotted their sporting benefits in the 1990s, compression wear is categorised as follows: 15-20mmHG, over-the-counter for mild swelling; 20-30mmHG, medical class I for preventing varicose veins; medical class II is recommended if you have a blood clot or deep-vein thrombosis; and medical class III is used for severe venous issues.
“Our recovery tights have a graduated mmHg of 30 at the ankles and 25 at the calves,” says Martin. “A tight for active use, however, has slightly lower pressure but still graduated at 30 and 20.”
MIXED RESULTS
We’ll come onto the benefits shortly but, despite the science and precision that goes into compression wear, evidence to support their use is equivocal. Take the research of Kieran Glanville and Michael Hamlin, who reported that compression tights didn’t affect blood lactate clearance – one of its aims – any faster than without socks after a 40km cycling time-trial. That said, they did conclude that subjects reported less muscle soreness than normal, stating that ‘these perceptions may be due to a shift in the participants’ beliefs during the course of the investigation’; in other words, the placebo effect. If you feel it works, it’s working.
Then again, recovery expert Shona Halson of the Australian Institute of Sport showed that compression socks worn between repeated maximal running bouts, 60mins apart, saw not only an improvement in performance wearing compression socks, but also that metabolic markers of fatigue in the muscle were reduced.
That ambivalence stretches to compression garments’ other mooted benefit: dampening vibrations during exercise. “The compression reduces muscle oscillation, which prevents micro muscle tears, reducing the
“Size is important to ensure a graduated level of compression at the optimum levels to assist blood circulation”
chances of cramp and injury, and lowering fatigue,” says Martin.
“Compression is particularly beneficial when running long fatigue-inducing distances and high-intensity sprints when oscillation intensity is higher.”
Though less weight-bearing than running, Martin stresses these movement-reducing benefits are also applicable to the bike. And there’s evidence they work, with one study in the Journal of Biomechanics 3D scanning athletes’ calves before and after exercise, both with and without compression socks, and showing a reduction in limb girth when compression garments were worn. “It’s proposed that this reduction’s a result of compression limiting the space available for inflammation to occur,” said the study. “This reduction in swelling is down to a reduction in the impact of muscle damage.”
Then again, a recent study funded by Nike poured cold water on these claims. They motion-tracked 20 runners on a treadmill for 30mins and, while they found compression garments did reduce muscle vibrations, they’d no significant impact on performance.
FIT IS KEY
So compression evidence is divided. But to stand any chance of enjoying the mooted benefits, fit – and applying the correct amount of pressure – is vital. 2XU has 13 sizes of men’s tights and 11 for women based on weight and height.
“For our compression socks we provide six sizes that look at not only your foot size but also calf circumference to ensure the optimum fit,” says Martin, who vouches for their efficacy by adding that their compression is tested with the global standard – a Salzmann device.
2XU offers more sizes than some but, the problem is, commercialism and compression aren’t happy bedfellows. “There’s some good evidence they work, but they must be custom-fitted to the athlete and the pressure needs to be very high,” says fatigue expert Robin Thorpe.
“When I was at Manchester United, I worked with Adidas using 3D scanners and created bespoke garments for every player. I think we were the only team in the world to do that. I can’t tell you the exact mmHg figures, but let’s say it’s more than off-the-shelf garments.”
Which again raises question marks over off-the-peg efforts like those from 2XU, Skins and Endura, the latter worn by Tim Don. “I wear them for every run,” the Don tells us. “I’ll sleep in them, too, if my calves are feeling tight. And I wear
“Future compression wear growth will come from smart garments measuring physiological metrics”
them for travelling – flying, especially, but also long car journeys.” Placebo or pressure benefits, it’s hard to tell.
RECOVER LIKE A PRO
The evidence is arguably stronger for Don’s other squeeze of choice – the NormaTec Recovery System. You might have seen these. You simply sit down and slip your legs into a pair of waist-high boots. Instead of compression socks, which use static compression (squeezing), NormaTec uses dynamic compression by sending a series of pulses through the boots. “Our patented pulsing action more effectively mimics the muscle pump of the legs and arms,” say NormaTec. “It greatly enhances the movement of fluid and metabolites out of the limbs after an intense workout.”
As they should for around £600. That and greater training volumes are why they’re generally more the preserve of the elite. “I use them for most of my sessions,” adds Don. “Usually it’s for about 45mins but sometimes 75mins. For me it’s like having a light 60min massage.”
Don admits he’s never objectively measured the results. “But my legs aren’t as sore and feel fresher. That’s good enough for me.” He also says that NormaTec provide an upperbody recovery option. Don doesn’t use it but it poses the benefits of compression wear for swimming. We’ll keep this brief as, certainly regarding static compression, there’s even less evidence behind their use than biking and running. Martin affirms that it’ll “reduce forearm fatigue and lactic acid build-up”, yet we’d argue that its proximity to the heart renders them less productive than lower-limb compression. But, if you wear them and you feel a benefit, why not?
That’s the state of today’s market but what of the future? Industry analysts forecast the compression and ‘shapewear’ market will reach a staggering $5.6-billion by 2022. Some of this revenue comes from bodyshapers such as Spanx, but a third is forecast to come from compression leggings and socks.
Where will this growth come from? According to de Medici, simply a more usable and useful product. “Firstly, you’re looking at better customisation of garments, ensuring a more bespoke fit and more comfort. Then we’ll have materials that more proficiently control temperature control. Finally, smart garments will gain a foothold to measure physiological and biomechanical metrics.”