Plus bowling 25 overs straight isn't too difficult once you've built some stamina up and aren't looking to knock the batsman over every ball.
I remember my teacher at school (and cricket coach) telling me that Ray Illingworth (I think, could have been Underwood) was offered a professional contract with an English league club, he accepted - but only on the condition that he would be allowed to bowl no more than 15 overs per game, because if he was allowed to, the club would have no young spin bowlers within five years.
Obviously depends what level you're playing at though, these issues are at a level of cricket far below first grade.
It's one reason why a lot of fast bowlers, and especially their clubs/teams/states, aren't keen on sending them over to club cricket in England at times. Or try to agree to such a limit.