Compression garments

The venous return argument is borrowed from medicine, where it is entirely sound. In chronic venous insufficiency, lymphoedema, and post-thrombotic syndrome, graduated compression at specified and measured pressures (typically 15 to 40 mmHg, highest distally) changes haemodynamics that are demonstrably abnormal. Compression stockings are real medicine for a real pathology.

The error is the extrapolation. A healthy seventeen-year-old has competent venous valves and a working skeletal muscle pump that moves venous blood far more effectively than a garment can. Fixing a broken system is not the same as improving a working one, and almost all recovery-apparel marketing depends on the reader not noticing the swap.

There is also a measurement problem specific to retail. Interface pressures in sports garments are frequently below label claim, frequently not graduated at all, and they drift with sizing, wash cycles, and wear. Very few studies report measured interface pressure, which makes the literature difficult to interpret even where it is positive.

The mechanisms that plausibly do operate are more modest and more interesting. Reduced muscle oscillation during running means less repeated soft-tissue vibration and possibly less mechanical damage. Reduced interstitial swelling changes the afferent input from a limb, which changes how sore it feels. And a snug proprioceptive envelope alters body awareness and perceived stability. Those are perception and oedema mechanisms, not repair mechanisms.

Hill et al. 2014 meta-analysed compression and exercise-induced muscle damage and found moderate effects on soreness ratings with small to moderate effects on strength recovery and creatine kinase. Brown et al. 2017, working across a wider set of protocols, found smaller effects overall, largest for perceived soreness and minimal for performance measures.

Blinding, again, is impossible. You know whether you are wearing tights. In a literature whose most responsive outcome is a soreness rating, that is not a minor limitation, it is the central one.

The trials also disagree with each other in ways that make pooling awkward: garment type, compression pressure (rarely measured), whether the garment was worn during exercise, after it, or overnight, and when the outcome was assessed. The most favourable protocol is continuous wear for many hours after damaging eccentric work in recreational subjects. The least favourable is next-day performance in trained athletes, where the effect approaches zero.

One use case is genuinely well supported and is not a recovery claim: long-haul travel, where compression reduces lower-limb oedema and, in at-risk individuals, thrombosis risk. That is medicine, and it happens to be the reason a team's kit bag has them.