1: Have a rifle in hands
2: Double-tap your forward key to go to your maximum speed
3: While running, open your inventory and USE any object, such as food or drinks for example

Your character will start an animation, it will get cancelled, and you will start running at maximum speed as if empty-handed.

Animations will be as if you were empty-handed, and the rifle you were carrying will be held in only one hand.

You will NOT use up a portion of food or drink or vitamins or whatever you used to do the bug.

Stopping does not cancel the bug, it stays until you drop the weapon.

You can not fire the weapon even when you stop, you have to "reset" your hold by dropping it and then picking it up again.