Conditioning and injury prevention is increasingly individualised at the top level. Warm up routines, sleep analysis (when & for how long, different for every individual), individual nutrition plans, recovery programs and, as you mentioned, cryogenics. Also, having the technology to prevent players being able to hide what they think are only small issues but might develop (which many of them do). I’m pretty sure that United currently don’t do any of this to much degree.
The science has increased incredibly in recent years, but that isn’t driven by St George’s Park. It is mainly by elite clubs in conjunction with research facilities around the globe. St George’s Park benefits from it, but mainly on the injury treatment side.
We are miles behind but there’s no shame in it because everyone in the EFL is.
My source is a medical professor who heads up medical & conditioning for a top PL club. I’ve been lucky enough to spend time at their training complex and what they do is mind blowing. The range of equipment wouldn’t fit into Shirecliffe. And the depth of the medicals that potential new signings are subjected to are beyond belief. That weeds out the ones who don’t have the physical and athletic attributes.
But it costs A LOT of money, so if the owners are prepared to go down that route it will be money well spent.