1. Start sprinting and alternate between A/D keys, notice inertia active
2. Let go of shift (or empty stamina) to return to a jog (still holding W) Now that you are jogging, continue alternating A/D inputs again - notice how inertia is still active even though you aren't sprinting
3. Let go of all movement keys and completely stop
4. Hold W to jog again - inertia will be disabled and character jogs as normal
Edit: In addition to letting go of all movement keys, the inertia can also be disabled by quickly flicking the mouse to the side, causing the character to do the 'turning around' animation.