like going once a week for six weeks? Your legs may just need more conditioning.
maybe try stretching after a few runs once your muscles are warm and then again at the end of the day.
You could also try adding some protein to your diet to help muscle regeneration.
I have HUGE legs. Very very powerful. Almost freakish. Great for short burst of brute strength but hot damn does snowboarding and other endurance sports make me want to hack them off!! I try everything from training to protein, to stretching to, icey hot, to ice, to just flat out doing it more. Nothing helps hahaha. By spring it is a tiny bit better but its barely barely noticeable.