[chakintosh]

That's in part why sprinters are jacked. They need to keep their core from leaning forward at such high speeds.

[SJC_Hacker]

My reference for "jacked" would be more like a bodybuilder. Sprinters aren't really "jacked" more like lean and muscular.

[cratermoon]

Professional bodybuilders all use steroids. There are "natural" bodybuilders that don't use steroids or PEDs, and a few competitions for them, but the sport in general is saturated in drugs.

[jessekv]

Compare sprinters with longer distance runners.

[hanniabu]

As a runner I find this comment hilarious. Not sure what type of relationship you see between speed and leaning forward, but there is none.