I am a female in my late 30s who is trying to race a fast (for me) half marathon this winter. I run 25-30 miles a week right now with my long run being 10 miles. Obviously this will increase before the half.
My question is how important is nutrition in terms of speed and performance? My diet is average at best. My weight is ok, I'm 5'8" and 125 lbs. If I switch to cleaner eating will it make a difference in my speed? Right now I eat an average American diet. Cereal for breakfast, sandwich for lunch, yogurt, and dinner is anything from burgers to chicken and rice to pizza. Not a lot of vegetables I'll be honest.