Why do male triathletes shave so much of their body hair?

I started shaving my bushy legs when my kid started grabbing fistfuls of hair to steady himself when learning to stand.

Now that I've done it, I'll never go back. It feels much cooler. I live in a very warm climate. Only down side is my partner complained about getting poked by my shaved legs in bed (and during the horizontal mambo).

--Pat