I run long distance and the paleo diet works for me as long as I keep up my carbs for my long runs of more than 10 miles. I really do have to focus on eating lots of fruits, veges and nuts to compensate or I lose weight very fast. I find I have to eat a bowl of oatmeal a couple of hours before a very long run or I just zap out after a couple of hours of running. During long runs I eat dried fruit, after 2 hours out I do take a packet of salt. Haven't read the Paleo for Athletes yet..hope I get it for xmas from one of my sons. :) training for my yearly marathon, 54 yr old female.