Like mentioned I'm running my first 15k. I've run half marathons before but thats besides the point. My question is, i use gels for half marathons but not 10ks. I was planning on using a gel for this 15k, but....i don't know if i should use it before race starts or if I should take it at the first 5k or 3 mile mark. I use the powerbar gels (caffeniated) if it matters. Thank you!