20 Second PR wrote:
I'm not convinced it's strength. Nutrition is a huge factor. The marathon is the shortest race where your body starts to run out of glycogen. If you're not an efficient runner enough runner, you're toast. Zersenay Tadese was toast today.
I agree with this. Getting the nutrition right is a trial by error for some people. The fact that Ritz consistently describes leg cramps in the latter stages of races suggests its a nutritional thing to me. Of course extra mileage in training and longer long runs would help to figure out what your nutritional requirements are too!