but you're only very temporarily raising your heart rate when cycling
basically cyclying is a more efficient way of moving around so you use less energy doing it.
(PsychoChomp, Tue 25 Jan 2011, 11:15, 2 replies, latest was 15 years ago)

I was thinking it was better to do short bursts
Rather than longer periods where you don't push yourself.
( Labia Majora You keep on talking but it makes no sense at all, Tue 25 Jan 2011, 11:17, Reply)

Depends what you're training for
but 8mins isn't long enough even for a short burst you need about 20mins at least.
(PsychoChomp, Tue 25 Jan 2011, 11:19, Reply)

that's what pisses me off about my cycle to work
it only takes about 10 minutes. It was hilly enough to knacker you, but not long enough to do any lasting good.
( Vipros. clever got me this far, then tricky got me in, Tue 25 Jan 2011, 11:22, Reply)

At the moment, 8-10 mins twice a day is helping me get back into it
Very soon I'll be tacking the extra 6 miles on. Then once that becomes easier, I'll push further.
( Labia Majora You keep on talking but it makes no sense at all, Tue 25 Jan 2011, 11:22, Reply)

For a given walking speed, yes.
but not many people cycle at 3 miles an hour. It's not strictly because it's more efficient. It's because it's non-weight bearing, so you are only accelerating your mass horizontally, not vertically against gravity.

cycling at 12 miles an hour requires 16 times as much energy, more or less, than cycling at 3 miles an hour. And 12 miles an hour is still a pretty slow cycling speed, even for someone unfit. And 16 times would easily cancel out the "non-vertical accleration" thing.
( the mighty badger Aphrodite, on a bar stool, by your side, Tue 25 Jan 2011, 11:55, Reply)