I'll wear a Camelbak when I know I won't be able to refill often enough ... still, I can't imagine drinking more than a bottle every 10 miles. I don't like to wear one normally on the bike, but there's one ride in particular that I do, if the weather's going to be hot. Loosen the shoulder straps and let the weight of it rest on the waist strap on your hipbones - that takes a lot of the pressure off your back.
What are you doing for electrolytes?
ETA: I've been close a couple of times on the bike, but the only time I knew it was bad was on a 95° day last summer when I set off on a long run and missed a turn, and wound up 13 miles from home with 4 miles' worth of water and no more than 5 more miles in my legs.
That's when I reached for the phone...
Last edited by OakLeaf; 04-09-2011 at 05:58 PM.
Speed comes from what you put behind you. - Judi Ketteler