Yes, the amount of work you do at a time increases as you go, BUT, that means your partner or you get to rest more, so there's a definitive win-win factor here, if you're a glass half full kind of person. If you're going to compensate something for how tired you are, hold back on the row. Slow progress is still progress on a rower. Slow progress is no progress when you drop a wall ball or kettlebell. So grab that good lookin' partner and let's have some fun for 25 minutes!