Immersing yourself in water (of any temperature) introduces a pressure gradient as a result of the weight of the water surrounding your body. The deeper submerged any part of your body is, the higher the pressure. This occurrence should be recognizable to everyone who believed the pressure in their ears build up at greater depths and has swum submerged in a pool.
Standing in water will result in a hydrostatic “squeeze. During and immediately after a hard workout, fluid from your blood diffuses into your muscles and the blood itself pools in your extremities. The hydrostatic pressure from water submergence counteracts both these effects: the overall pressure gradient squeezes blood from your legs back towards your center, and also the fluids are squeezed by the increased localized pressure on the muscles back into the blood.
If you will check out https://www.prideontheline.com/, you will get to know that the increased outside pressure also increases the efficiency of your heart, letting it move more blood per beat. It’s postulated that these three reactions are biological markers for muscle and exhaustion damage are reduced following cold-water immersion: the water pressure reduces inflammation in the muscles and helps clear out waste products.
The effect of cold temperature
The impacts of cold temperature are well-understood since just a couple of studies have compared cold water submergence with room temperature immersion.
Nevertheless, it is known that cold-water immersion reduces the ability of fluids to diffuse into and between muscle cells, which reduces inflammation and so-called damage that was secondary. This really is why doctors recommend icing instantly after an acute injury like an ankle sprain, since the damage may be exacerbated by prolonged swelling and inflammation from fluids pooling at the wounded site.