Wikipedias rationale for that decision was it uses a lower proportion of anaerobic metabolism since you don't need as huge bursts of energy, so you're using you're aerobic metabolism more of the time and burning more fat. Doesn't make a whole lot of sense though, i mean if you exercise harder you''ll be burning more calories in total anyway *shrug*.
All things considered it is terribly slow, i tried it at the gym the other day on the bike, it has this thing where it adjusts the resistance to try keep your heart rate within a certain range (it asked for weight and age, i think it was using one of
these formulas, it spat out ~140) it was easy...too easy infact. Took ages as well to get to what the bike said was 50 calories, like 10-15 minutes, after that i gave up and went as hard as i could and got 50 in like 5 minutes.
Apparently
High intensity interval training works rather well. You burn less calories while you're doing it but it says your body uses more energy afterwards reparing itself and things like that. Might be a bit hard for an unfit person though..