What Is Compression Wear and How Does It Work?

Compression wear is clothing made smaller than your body, so it has to stretch to go on, and the stretched fabric presses back on your skin. That pressure is the whole product. Everything compression is said to do starts with how hard the fabric presses and where. This guide explains how the pressure is made, how it is measured, what it changes inside your body, and which popular explanations the research does not back.

How does a stretchy garment create pressure?

A compression garment creates pressure through tension and curve: the harder the fabric is stretched, and the tighter the curve it wraps round, the harder it presses. A 2018 review of compression garments in the journal Polymers describes them as designed smaller than the body they fit, so the fabric is under tension the moment you put it on. Engineers turn that tension into pressure with Laplace's law. In a 2015 review in the Journal of Sports Science and Medicine, Beliard and colleagues calculated garment pressure as the fabric's tension multiplied by the curvature of the limb beneath it.

A narrow part of your body curves more sharply than a wide one. So the same stretch presses harder on an ankle than on a calf, and harder on a calf than on a thigh. That one rule explains three things you notice in compression: tights feel firmest low on the leg, the same garment presses differently on two people of different builds, and a different size changes the stretch, and with it the pressure everywhere.

How much pressure does compression wear put on you?

Sports compression tested in research ranges from barely any pressure to more than a medical stocking. Pressure is measured in millimetres of mercury, mmHg, the same unit as blood pressure. Beliard's team gathered the garments used in published trials of leg compression in athletes, measured 12 of them in their own laboratory, and, with the published figures, found ankle pressures from 1.1 to 46 mmHg and calf pressures from 8 to 39 mmHg. In most of them the pressure was highest at the ankle and fell towards the knee.

Medical compression stockings, by contrast, come in classes set by the pressure at the ankle. An NHS guideline from Bristol, North Somerset and South Gloucestershire lists the British classes as 14 to 17 mmHg for class 1, 18 to 24 for class 2 and 25 to 35 for class 3. A sports garment can sit below, inside or above that range, so the word compression on a label does not tell you which.

Does more pressure work better?

More pressure has not been shown to work better: a 2015 review of compression trials found no clear link between how hard a garment pressed and whether it helped. Across the trials it covered, garments at low pressure and at high pressure both produced positive results, and both produced none. Six of the studies tested more than one pressure level on the same people, and only one of those six found that the effect depended on the pressure. In the authors' words, the factors behind compression's effect remain to be worked out.

So a garment that hurts is not doing more for you. Pressure has to be there for clothing to count as compression, but past that point, the research gives no reason to chase more of it.

What does compression do to your blood flow?

Compression speeds up the blood returning through your veins, at rest, during exercise and in recovery. A 2023 meta-analysis in Sports Medicine by O'Riordan and colleagues pooled 22 studies of sports compression and blood flow. Flow in the veins, the blood heading back to your heart, rose at rest, during exercise and in recovery. Flow in the arteries, the blood heading out to your muscles, rose only during exercise or a change of posture. Straight after exercise, neither changed. The effects were small to moderate in size.

Veins have thinner walls than arteries, so pressure from outside narrows them more easily, and blood moves faster through a narrower vein. That is the oldest idea behind compression, borrowed from medical stockings, and of the explanations in this guide it has the strongest support.

Does compression stop your muscles wobbling?

Compression reduces muscle wobble: studies of compression shorts and tights found less muscle movement, and less effort spent holding the legs steady. Every footstrike and every landing sends a shock through your leg muscles, and they work to damp it. A close, stretched layer holds them from outside, so they have less to do. The studies are set out on the compression tights page for running and the compression shorts page for jumping.

Does compression sharpen your sense of body position?

The evidence on compression and body-position sense is mixed: one study at the knee found no gain, another found knee sense held up better late in a long run. Proprioception is your sense of where your limbs are without looking. It is a popular explanation for compression: pressure on the skin is said to sharpen the signals your brain gets about your joints. In a 2018 study in PLoS ONE, Négyesi and colleagues put 24 healthy young adults in an above-knee compression garment, and MRI showed it squeezed the thigh by 2%. The researchers moved each knee to a set angle, moved it away, then asked people to signal when it was back at that angle. In the garment they were no more accurate, and their errors were smaller without it.

Fatigue may be where the difference shows. In a 2022 study in Frontiers in Physiology, Chang and colleagues had 18 half-marathon runners run 21 km on a treadmill twice, once in compression running pants and once in loose shorts. Before the run and after 7 km, their knee position sense was the same in both. After 14 km and 21 km, it held steady in the compression pants and slipped in the loose shorts.

A study on the compression vest page also found better throwing and golf accuracy in an upper-body compression top. So position sense may hold up better in compression late in long sessions, but a few small studies are not enough to call it proven.

Is sports compression the same as medical compression?

Sports compression is not medical compression: medical compression is prescribed at a set pressure to treat a condition, while sports compression is training wear with no agreed pressure. Medical stockings are made to a class and chosen after a clinical assessment. Sports garments are picked from a size chart, and as the figures above show, their pressure varies widely. Do not use sports compression to treat swelling, varicose veins or any other medical problem.

The same NHS guideline lists people who should not wear compression stockings at all. They include anyone with suspected or proven peripheral arterial disease, nerve damage or other loss of feeling in the legs, or fragile skin. If any of those applies to you, ask your doctor before you wear tight sports compression too.

So how does compression wear work?

Compression wear works because stretched fabric presses on you, hardest where your body curves most tightly, and that pressure speeds blood back through your veins and holds your muscles steadier. Those two effects have measured support. Sharper body awareness has mixed evidence, and higher pressure has not been shown to do more. What all of this adds up to for your training, recovery and race times is set out where you can shop compression wear from 92.

Sources

• Xiong Y, Tao X. Compression garments for medical therapy and sports. Polymers, 2018.
• Beliard S, Chauveau M, Moscatiello T and others. Compression garments and exercise: no influence of pressure applied. Journal of Sports Science and Medicine, 2015.
• O'Riordan SF, Bishop D, Halson SL, Broatch JR. Do sports compression garments alter measures of peripheral blood flow? A systematic review with meta-analysis. Sports Medicine, 2023.
• Négyesi J, Mobark A, Zhang LY, Hortobágyi T, Nagatomi R. An above-knee compression garment does not improve passive knee joint position sense in healthy adults. PLoS ONE, 2018.
• Chang L, Fu S, Li J and others. Effects of compression running pants and treadmill running stages on knee proprioception and fatigue-related physiological responses in half-marathon runners. Frontiers in Physiology, 2022.
• NHS Bristol, North Somerset and South Gloucestershire. Guidelines on the use of leg compression hosiery, 2021.