I would think an elliptical would produce more power because the body is more adjusted to walking/running than pedaling a bike. The arms may help too.
In a way, I agree.
Yes, the body has evolved to walk/run vs. bike - no real argument there. However, pushing anything with your upper body is not a natural walking / running mechanism.
IMO... while some short term power gain with full concentration may be achieved 'pushing' with your arms as well as your legs, natural shoulder / arm / elbow / wrist / hand movement is best as counter balance to aid in stabilizing core from power created by largest lower body motors - hamstrings, quadriceps, rear end and such. Think helicopter. Think human legs = main rotor+jet (lift and thrust), where human arms = helicopter stabilizers (to keep you balanced so that you can lift and thrust again in the right direction).
When you watch folks 'work out' on these things they really aren't 'pushing/pulling' with their arms. If they did they would be maximizing their effort, (which was liklely the intent of the things) but not necessarily their workout. On a bike you use some natural upper body reaction vs. bars to stabilize, although gyro takes care of
most of balance, and to generate massive torque when required (hills/passing/wheelies).
When you think about leg pressing 450lb 30reps vs. triceps 50lb 30reps the 10:1 'ness becomes clearer. Even on a stationary bike I think you'd be better off using the 10% on balance / short term extra torque ( & higher current flow
)
I think you'd be fighting your natural balance for 36 of the 40 minutes, which is great for sweating... and focusing on using your arms for only 4min. helping push pull
really well during that stint. I suppose if you were to alternate a bit, you could give your legs a 'rest' - but if you are riding within yourself this is not an issue.
I would love to be wrong about kinetics and see people getting 320W continuous with addition of arm movement though.
This is not to poo-poo the flywheel. That (I believe) is like a giant cap, and should help some.