When you're wearing sneakers, do your shoelaces become untied, unless you do a double knot?
Scientists have figured out why and this could mean we will all be turning to velcro in the future.
According to a recent study, scientists have discovered that running can produce a very strong g-force... up to 7G.... which is stronger than even the most powerful roller coaster in the world, which produces a g-force of 6.3.
So, that constant pressure on the knot causes it to loosen and eventually causes it to unravel completely.
The solution may be to do a square knot on your shoes...like this...