Hello, I'm 61 and now on week 3 of Couch to 5k. I've done very little exercise since my 40's. Not doing too badly although I do find I'm very tired the day after a run and often need two days off between runs. Biggest problem now is that I'm getting shooting pains down the back of my right leg and these go on and off even during days I'm not running. Is this something I should try to keep going through or not? I really don't want to give up!!