Question is simple: Where does the benefit in taking a cold shower lie? Is the benefit in jumping into the freezing water and shocking your system? Or is the benefit in exposing yourself to the cold?

Some resources I have read adovacated starting warm, washing and then finishing by dropping the temprature. This is currently what I do and I can quite quickly get it down to the almost freezing tempratures. This causes heavier breathing, but not same severity of shock and convulsion that jumping head on into it does.

By taking this approach am I missing out on the main benefits of taking cold showers?