What difference does it make?

neeb

I don't have any specialist knowledge here, but I would guess that running is less efficient than walking as you're constantly using energy to (effectively) jump up in the air?

Now.... pulling that PhD thesis off the shelf.... there it is... p35 "running displays a near constant metabolic cost, in relation to the distance travelled, for increased running speeds. These observations are supported by Harris et al. (2003) who report no change in mean metabolic task cost...with running speed." I can't see why it would be different for cycling on rollers.

Interesting. These two statements aren't actually contradictory, as it could be true that the metabolic cost for distance traveled is the same for running whatever speed you run at (presumably air resistance is a very minor factor compared to cycling), but that there could be a difference between walking and running. Walking and running are two different gaits, two different mechanical mechanisms for converting energy into motion. With cycling however (as with running) the mechanism is the same at any speed, so on rollers possibly there is no difference, as long as the exercise is all done within the same metabolic system (aerobic, anaerobic)? I suppose you could think of the latter as being "gaits" in the metabolic sense....

neeb

this is because power - speed on a bicycle is a cubic relationship.

Is this all due to air resistance though?

Alex_Simmons/RST

neeb wrote:

this is because power - speed on a bicycle is a cubic relationship.

Is this all due to air resistance though?

the cubic part is but there are many resistance forces which act in different ways relative to speed

bompington

I wonder if this has got anything to do with the fact that in 2 hours I can cycle 40 miles, run 18 or climb a 4000ft mountain - but a couple of hours wandering round the shops with Mrs Bomp leaves me knackered?

milese

I was once told that running a distance uses less energy then walking because when you run you take bigger strides and benefit from the non energy consuming spring in your muscles (achilles I think).

Might be nonsense.

Percy Veere

If its any use....

When I first got the Alp d'Huez RLV for Fortius I cycled it in 1h 56 mins (don't laugh)
Second time around I did it in 1h 42 mins, but the calories were EXACTLY the same (1006).

antfly

That don`t mean nothing.

Percy Veere

And that's a double negative :roll:

It does mean something. You output more power in a shorter time, or less power over a longer time, effective output is the same.