Do you guys think there is a difference between the two? I mean, d1 college programs especially the top ones do tons, and tons, and TONS of running. You think these players are in better shape or if not the shape amount of fitness as professional players overseas?
NCAA substitution rules are different. The result is teams can play 20 field players in each half. So the players on teams that do that are fit enough to play flat out for 25-30 minutes at a stretch. On professional teams at least 8 field players have to go the whole 95 minutes.
Without being overly simplistic, professional players have a job, whereas for college kids playing soccer it is a side job. College players have to go to class, and are restricted during the off season and season as to the number of hours that they can spend on soccer.
There are no rules restricting independent voluntary training, but there are practical limitations due to academic and other commitments. The rules limit the commitment of the student athlete to the school program. The rules are necessary to protect the student.