Bryan Bateman wrote:
told me that the body develops hair in order to protect itself
I also wonder whether this might be a similar effect to shaving; the hair being worn off at the follicle level and growing back thicker, or with more than one hair growing in place.
I've been training for two and half years and already have noticeably hairier wrists...
As I was told when I first started Aikido, make sure you don't pick a fight with someone who was large forearms and hairy wrists