|Foot strike plot borrowed from here|
To begin at the end, it takes between 150 and 250 milliseconds from the moment your foot touches the ground until the tips of your toes leave during take-off. The time of your foot strike is proportional to your speed. As you run faster, your footsteps take less time. But even at a slow jog, the time it takes for a sin
gle step is short. For instance, assume you are running at 180 steps per minute. If each leg is taking 90 steps per minute then each stride cycle lasts 0.667 seconds. The time of each kick is at most half this time (because the opposite foot has to return to the start positing in the same amount of time) so that your foot landing, takeoff, and mid-air float last about 333 milliseconds.