I have the same problem. After about 5 miles / 40 mins my left foot gets pins and needles and then goes completely numb. I've tried loosening my laces, but now get a large blister on the arch side of the sole of the same foot. It's really frustrating, as the pins and needles feel odd, and the blisters prevent me from training as much as I'd like. I'll try these stretches and see I guess.