Originally Posted by Maelochs

Those of us with a history of heart issues might be a bit more concerned with load on the heart ... if I spin too long sometimes my heart rate will spike and then I can't really do much ... standing or sitting ... except maybe sit down, on the side of the road.

I have to stand every now and then, and yes, it still puts a big load on my heart, but the tiny bits of rest between strokes (versus spinning a faster cadence) can extend my climbing capacity just a little bit, so that sometimes i can actually make it up the slight inclines which pass for hills around here.

Not that I couldn't climb a serious hill ... it would just take a while, having to push my bike and all.