So that's what the extra shoelace hole is for!

This tip is for people who are tired of getting blisters on their heels when they go running, walking or hiking.

You can prevent these blisters with a “heel lock” or “lace lock” that creates extra friction between the laces at your ankle. This keeps the ankle and heel area nice and tight, without having to tighten your whole shoe. It also helps to prevent black toenails by keeping your heel and your toes from smashing into the front of your shoe.

Here’s how to tie a “heel lock” or “lace lock”. A lot of running and hiking shoes have an extra shoelace hole at the top (if your shoes don’t have an extra hole, just use the top regular hole instead). We’re going to use these holes to create loops on the inside and outside of our shoe.

Once we have created loops on both sides of our shoe we cross our laces and insert them into the loop on the other side. We then cinch our laces down. Make sure to pull the end of your laces down to create the actual “lock”. Lace your shoe in a balanced shoelace knot and you’re done. No more shoe blisters!
https://youtu.be/IijQyX_YCKA