I have an issue with my leg that makes running difficult for anything over 45 minutes of running, but l can still get away with doing sessions all on the grass. So far l have had to cut back 2 weeks. Going from 3 months of 3 doubles a week, sessions, and long runs, and 80 miles per week, to now doing 5 to 6 miles a day and one hard and mabey one light session on the grass. How much fitness will l lose if l keep this up for a month till l can run over an hour with no issues? The issue is loss of leg coordination, but since l rested up it's only is an issue after 45 minutes of running. I have basically no problem running 30 minutes and close to 45 minutes, but after that issues start.