A. During a training session, your muscles burn fuel and that creates a build-up of toxic waste products and lactic acids. Your body eliminates these waste products naturally over a day or two, but Immersion in chilled water can do the same in a very much shorter time. The sudden cold sets off a reaction in the limbic (ancient) area in the base of your brain that is programmed to respond to such dramatic external events, in this case it senses that you might be freezing dangerous and immediately begins an automatic process to restore your bodies core temperature to safe levels. It does this mostly by withdrawing most of the blood from your skin and outer soft tissue and muscles in to the core of your body. The blood must pass through your liver, kidneys and other organs that each do their job of removing these dangerous toxins and waste products. This quickly eliminates most of the soreness and help torn muscles to rebuild much faster with fresh oxygenated blood flow and you are ready for your next athletic session much more quickly. In effect the sudden cold water tricks your body in to an ancient survival mode because it “believes” you are in danger of freezing. Of course you are actually quite safe, but the effect on your body of quickly and completely flushing the waste products from your blood is extremely beneficial. One of the most popular benefits of regular ice baths and the more most often reported by athletes , is far better sleep patterns and a much calmer mental state. This has been extensively documented.