I've been running for the last 9 months and am now training for a half marathon. In the beginning of my running, I was going to physiotherapy because my calf muscles on my right leg were very tight and impeding my running. The physio helped, so I stopped, but continued stretching. Now, after I run about 3km, my right foot starts to tingle, and it goes right up to my thigh to the point that I have to walk it off. Loosening my laces didn't help. For the last 2 days, about 90% of the day I have tingling in my lower leg.