I’ve never been a huge believer in a rough schedule being a good excuse for bad, or sloppy play. Keep in mind as kids we would travel to tournaments, get minimal sleep, eat unhealthy, play five games in three days, and ultimately have similar results in each of the five games. The NHL isn’t much different. Sure the physical demand is impossible to compare, but NHL players have so much more to rely on.
Personal Trainers to tell them exactly what to do, and what not. What to eat, and what to avoid. Coaches who meet with the greatest masterminds of the sport to make sure their players are in the best possible environment.