Why is it that I can train for 30 miles a week - long, speed, pace and easy sessions...up to 10-12 miles on the long runs without ill effect and as soon as I run a 10k or half marathon I get very tight sore hamstrings for 2/3 days afterwards. I do all the recommended stretching but they always flare up - can anyone enlighten me?...and better still tell me what I can do about it?
