Ever since 7th grade, running has been a part of life, and just now it as occurred to me, I have no idea how it works, obviously its putting one foot in front of another, but why does this happen? let’s take a look.
To start think of you arms and legs as pendulums. The equation for a pendulum is d2o/dt2+g/l=0. In this L is length meaning if you shorten your pendulum or legs in this case you will go faster. You probably do this when you run without noticing it. Do you every run with a straight leg no, you bend them, thus you shorten the pendulum. Now this put your arm down to your side, straight. try swinging back and forth, not very easy or fast. No put your arm at a 90o angle and swing, easier right? This is because you made you pendulum shorter.
There is other ways to get physics to work for while you run. When you lean back you push against gravity and are being slowed down, to make a sprint or kick at the end of you race easier simply lean (at the ankles, not the waist) and let gravity pull you, you will go faster with putting in more work.
It is also important to know the forces involved in running. The first one is Newton's action reaction law. For ever action there is an equal and opposite reaction. This is shown in this diagram,
When you push down off the track the track is doing the same towards you and applies a force in direction of you center of mass. This means the more force you push down with the more will be exerted on your body. The force from the track or running surface causes a shockwave up your leg. This tend to the root of many overuse injuries in running such as shin splint and why all runners should invest in good shoes to help lessen the shockwave. To see a video of this click the link below.
The final and most important part of running is stride length. This is what gives you your power. (P=w/t) This is why it is important to regulate stride length. Too long of strides and will put in too much power to hold over a long period of time, too little stride and you won't have the power to get the speed you need. This is because the Work=Fd and to have enough power you need more work in a short period of time thus supporting the why stride rate is so important to running.
I hope you enjoyed this as much as I did researching it and maybe you will be just a little faster because of this. Don't forget to come out and support the IHS track team April 24 and 30 at home on the track and see some of this in action!