It is up to us to test all of these things and find what works for us. It really does not matter if research finds, for example, the ice bath doesn't do what is claimed. If it makes us feel good - it is good, and we should persist with it. I really do believe that the most powerful training effect happens when the physical training is combined with a fundamental belief that we are doing the right thing and we will therefore continue to improve. In other words the belief in an action makes that action potent.
This is the placebo effect and it is incredibly powerful. However there is an evil twin brother: the nocebo effect, where if you think things are going to get worse the probably will. This means that if we think we are in a rut and will never get faster then the training has a double load to carry and it becomes more difficult to maintain a schedule.
We therefore have to believe in what we are doing. But the placebo effect is also mysterious (for example the colour of pills affects their effectiveness) and cannot be easily and directly summoned up. In part it is built on our underlying cultural attitudes, which would explain the meanings attached to colour. It would also explain some of the attraction of ice baths, because there is a long, deep and conflicted attitude to bathing.
I have been reading Clean by katherine Ashenburg, that relates the story of something we take for granted, i.e. washing, and its cultural meaning.
I liked this passage about the gymnasium in ancient Athens:
Greek athletes, who exercised in the nude – gymnasium literally means “naked place” - first oiled their bodies and covered them with a thin layer of dust or sand to prevent chills. After wrestling, running or playing ball games, the men and boys removed their oil and dust, now mingled with sweat, with a curved metal scraper called a strigil. After using the strigil, athletes could wash, either standing up at a basin or in a shower or a tub. Although hot water would have made their oil and grit much easier to remove, there is no evidence that the gymnasiums offered hot water before the Roman period. The manly rigour of cold water bathing suited the gymnasium's spirit and reassured Athenians who brooded about the weakening and feminising effects of hot water.
She goes on to say that the attitude of equating hot water with softness and decadence is very persistent. The British Empire was built on the rigours of a cold morning bath and a modern German expression for a man short on masculinity is warmdusher, or warm shower.
So there you have it: those who like an ice bath after a run are as much following the tradition of the gymnasium as they are acting on an understanding of physiology.
Me I still like a tepid shower but having read this book I realise that I ought to keep quite about this if I meet anyone from Germany.