How does intertia affect gymnastics

Inertia is resistance to changes in motion. Which means if you are at rest it takes an external force to get you moving. And once you are moving it takes an external force to change the direction of that motion. 

For a person doing gymnastics the point that is subject to the above statement is her center of mass (roughly her belly button) . 

So for example, once you launch into the air, gravity is the only significant force on you. It keeps you from traveling out into space by pulling you down and the trajectory of your belly button is a parabola. Now there is nothing you can do with your muscles (internal forces) to change that trajectory, even though you can do twists & turns about the center of mass. The height and range of the parabolic trajectory is determined by the angle & speed at which you initially launch yourself.

inertia is one of newtons laws of motion so an object in motion tends to remain in motion until another force acts upon it that is what newton said when you are doing a back hand spring it is easier to keep going then to stop


Hope this helps!!! :D 
I love gymnastics