As a rugby player, its definately rugby. Try doing repeated sprints while you lift wieghts between the sprints for 80 mins and i mean heavy wieghts like firing a 14 stone foward into the air a few dozen times mixed in with the sprints or trying to push 8 brutes about the park in a scrum. Not to forget tackeling, rucking and running more lines. Taxes your aerobic and anaerobic capacities to the max.
Other than rugby, rowing is also extremly demanding
Other than rugby, rowing is also extremly demanding