Every pair of trainers we've ever owned has had extra shoelace holes and until now, their purpose has been a mystery.
But a new video has enlightened us, by showing that those extra holes are actually really useful - especially if you're a fan of running.
The video, created by Illumiseen, demonstrates how the extra holes can be used to create a "lace lock" that secures the foot in the shoe.
The idea is that this superior tying method will prevent runners from getting blisters by stopping their foot from slipping.
Here's how it works:
Step 1: Loop each lace back on itself through the extra hole
Step 2: Cross the laces through the loop you've created on the opposite side and pull downwards.
Step 3: Tie your shoes like normal