Very few humans go after this type of the training. In my "math talent" school (most of the Serbian/Yugoslavian medal winners came from it), at most a dozen students "trained" for this over 4 high school generations (500 students).
Problems are certainly not trivial, but humans are not really putting all their effort into it either, and the few that do train for it, on average medal 50% of the time and get a silver or better 25% of the time (by design) with much less time available to do the problems.
