Yes, and that's true for pretty much any esports titles for a multiple of reasons. Games on fixed yearly schedules like League of Legends make players run a pretty long marathon, offering few breaks during and even after the season. Professional scenes revolving around world championships have a lot of prestige and millions that one team wins and the rest don't, all happening in less than two weeks. Practicing with the team, reviewing games, and then honing your skills individually for 12 to 14 hours in total is pretty grueling as well. Note that most squads do all of the above six days a week.