How a rider pumps a swing higher
A swing is a pendulum: it trades height for speed as it moves through its arc. At the bottom, it is moving fastest; near either end, it slows before reversing direction. A rider can add energy by moving their body in a rhythm that matches this motion—not by simply flailing their legs.
The body changes the pendulum
When you bend or straighten your legs and shift your torso, you change how your mass is arranged around the swing’s pivot. That changes the swing’s effective length and how its motion responds. Your muscles also push and pull against the seat, doing work on the moving system.
Timing is crucial. A well-timed movement nudges the swing in the direction it is already traveling, adding a little energy each cycle. Move at the wrong part of the arc, and the effort may add little—or even work against the swing. The exact sequence of leaning and leg movement depends on the rider’s position and the swing’s motion, but the principle is the same: coordinate your body’s motion with the swing’s rhythm.
Small pushes accumulate
Each successful cycle adds a bit more energy, so the swing reaches a higher point before turning back. The rider is not creating energy from nowhere: muscles convert stored chemical energy into motion. That is why a child can keep gaining height without anyone pushing from behind—and why the same movements become ineffective when they fall out of sync.
