They run correctly on your regular size have , and medium is perfect for the average width foot. Finally, several times when I ran the motor at speed 5, it cut out and died after a few minutes - I could only run it at lower speeds. Il est amélioré par la réduction de bruit alors quon aurait pu sattendre au contraire, du coup je nécoute quavec. Thanks Adidas! I returned the Sz 8 and ordered a 7, but when they were still too large and too wide. They do not, however, run well causing one to have to scrunch ones toes to keep them in place. The 520 really shines here and the sounds of exploring the jungle of Libertalia or the bass-heavy notes of gunfire and explosions are spot-on and impressive. Both returned & I ordered reefs in attempt to find a new favorite. It?s got a pedometer, measures steps taken, calories burned, heart rate, etc It supports tons of sports modes- walking, running, biking, hiking, climbing, treadmill, yoga & MORE. Looks very nice installed and looks quite sturdy.