You have to ask why?
It’s simple. Carbon, energy drinks and risk alone does not win races. Neither does a gasping motor. The fact is aluminium or steel can still be the hardware of champions, not all the athletes drink the stuff they promote, and while all racers will all take a gamble in the heat of the moment, you can bet your bottom dollar that in each and every winner the generators will be strong.
A decade or so ago, athleticism and downhill were not the best of comrades, and many racers simply preferred the booze and bikes approach. On the surface at least. Nowadays its cool to post yourself in the gym, and a source of banter to goad your rivals into squatting or deadlifting ridiculous weights.
A good coach will be your guide and your motivation in the gym, they will get your body into a shape that will take the beating dished out by a downhill run much better than an untrained version of you. Stronger, fitter, faster. That’s the idea at least. A bad coach on the other hand will do the opposite for it will it will be they who are beating the shit out of you more than a track.