Originally Posted by
jfowler85
Either way, just getting on your bike is loading your heart up; unless you're trying to sustain anaerobic cardio for long lengths of time then I wouldn't worry about loading up the heart, that's what it's there for.
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.