Originally Posted by Oso Polar

Well, I don't know the real explanation behind it, something in our human physiology, but the fact is, more upright is your position on the bike, the more difficult it becomes to "ride hard", it is simply impossible to put down the same effort on the pedals compared to angled body position. It is not about aerodynamic drag, it just seems that purely upright posture doesn't allow muscles to work full power for some reason, like you have some kind of power limiter applied. You'll find out that if you'll try to pedal hard, you will incline your body forward even on a bike designed for upright posture - you'll start to bend your hands more, so that upper body will angle towards the bars. At which point you'll be better of (feel more comfortable) on a bike that is designed with less upright position in mind.

So, basically, the way I see it, too upright posture is working as a power limiter, prevents you reaching your peak power output, so it is not efficient for burning calories fast - in short but hard rides. It'll be "hard" ride as in "feel tired and uncomfortable" but not from the perspective of how much calories you actually managed to burn. And if you think that you can ride at relaxed pace (for which upright posture works great) but much longer distances then you'll find out that such position sucks for long rides as well because there is too much weight on your buttocks and spine, they'll get tired and stressed - especially if the road surface is of bad quality. I'm not saying that you want to ride as a racer but you don't really want to be too upright either. And riding short distances at relaxed pace (for which upright position works quite well) will not burn much calories simply because bike is a pretty efficient machine, it doesn't require much effort to ride.

As for "needing more effort to accelerate and keep moving" part, this is quite common and very flawed argument. For some reason it is quite a popular belief that horrible quality heavy BSO with heavy wheels, knobby tires etc. is better for exercise because it is quite difficult to make this thing move fast, if at all. The reality, however, is that your power output is your power output, effort you are comfortable with is the effort you are comfortable with, so on a better bike you'll not spend less efforts - you'll just move faster. Probably actually be slightly more efficient in calorie burn on a better bike simply because of less time wasted dealing with various issues.


Hmm, did I write something about flat bars here? No, I didn't!