@alfapredatorin r/Sprinting • Recommends
On “What is this machine (from Su Bingtian Documentary)?”
It's a keiser machine. So for most equipment normally the initial part of the motion feels the hardest, because the weight has no velocity on it. Once there is velocity you actually apply less force as you move the weight (i.e. the weight feels lighter as you begin to move it). (e.g. [video
With pneumatic equipment it ensures that you're applying a similar amount of force throughout the entire range of motion.