Have you ever wondered why running shoes have extra holes at the top? How many of you people use those? Well, I don't. It's one of those little mysteries that most of us have in our lives. No, it's not a not a design flaw. And of course, it's not for ventilation. Turns out those eyelets serve an important purpose. The trick is to create 'heel lock' or 'lace lock' with those extra holes which creates extra friction between the laces at your ankle. Check out the video to know how it's done: