To my mind, olympic rowers in these time frames (6 minutes), out perform any other athlete type.
The athletes are frequently tested on ergometers (flywheel machines). The world record a few years ago was 5 min 36 s.
over 2000 meters. That's a continuous power output
of 590W, i.e. work done on the machine. Over 500M (1m 16s) these guys can exceed 1HP. I've tested at the 2k distance a hundred times in competition and came in, ehem, somewhat lower. The typical top 10 school college rower (male) will rate at about 430W.
BTW, the do-it-yourself helo would have to hold that record holder's 97kg, 2m to get that power: