I was a hockey scout for years, and the level I scouted was 14 and 15 year olds getting ready for major junior. These kids had practice before school most days, so they were up at 5am to get to the rink by 6am. Practice for an hour, then a full day of school and a game or two during the week for league play. Then Friday through Sunday were the tournaments where they would play at least three games. Hockey games are 60 minutes long, and at that level, coaches were basically rolling two lines when they were trying to win. So the kids were playing 25-35 minutes per game (forwards toward the lower end of that range, defensemen toward the higher end).
The league I was scouting for had practice every day before school, with a 67 game regular season, four rounds of 7 game playoffs, and then the league champs would go off to another tournament after that. The kids who had been drafted to the NHL would then finish the season in the AHL or NHL. And the best of those played for their national teams over the Christmas break instead of getting the only break the league had. The season began in September and ended in late May, and there was at least a back to back every single weekend and often a back to back to back with travel (often two home and one road game, or two road and one home).
Some of the kids chose college instead of junior, and those kids had a full college courseload as well as practice every afternoon, a full day of travel and a back to back to back every weekend. The schedule was shorter, but the rigors of the college courseload were more difficult, and the best players represented their country over Christmas break and left for their AHL or NHL teams when their season ended, and they played through the other breaks.
So it's always been fascinating to me that basketball players whine about back to backs. Seeing 14 and 15 year olds have a hockey game at 9am and then another one at 7pm, then one the next day and the day after that and still have the energy to go to classes and practices...
I guess that's one thing I'd change about basketball. Toughen the fuck up already.