[EDIT] My idea there, is that internally fat individuals[1], are having trouble exercising parts of their body located near their center of mass, even if they are athletes. Not all athletes obviously, but most of them. Being hit by some other person at that area, seems the most efficient way to remove the fat particles. The only thing I had to do, is find a way to emulate it, but with less danger and not requiring a second person.

[1] https://en.wikipedia.org/wiki/TOFI

Spot reduction / targeted fat loss is considered "disproved" https://en.wikipedia.org/wiki/Spot_reduction, https://www.yalescientific.org/2011/04/targeted-fat-loss-myt...

General fat loss will remove fat anywhere, area specific exercises will tone said area (like abs) which will make them feel firmer which gives the impression of fat loss in a specific area.