Help me out regarding power??

rafregt1 Posts: 52
A thing that I can't get my head round regarding power?

Two riders ride the same segment at the same speed side to side so no drafting benefits and both finish exactly the same time.

Both have completely different power readings one high and one low..

Who is the fitter individual the one who puts out less power or the one who puts out more?

Thanks in advance..


  • cougie
    cougie Posts: 22,512
    Power doesn't matter. We race for first across the line not who's got the higher power.
  • reacher
    reacher Posts: 416
    cougie wrote:
    Power doesn't matter. We race for first across the line not who's got the higher power.

    To this guy it does or he wouldn't have asked, its a basic question that a lot of people who haven't got power meters struggle to get their head around is the measurement of power and what it means in relation to riding, my guess is once you ride with power meters its probably very easy to understand
  • cougie
    cougie Posts: 22,512
    The less power guy would have to be lighter or more aero.
    Doesn't mean that he's fitter.

    You could do watts per kg if you want but it still doesn't answer the question of who's fitter.
  • If you are looking to gauge overall fitness (taking things like equipment, conditions etc. out of the equation), you would need to know other physiological variables of both riders to gain a more accurate picture as to who may be fitter, you can't ascertain from power alone. There are lots of indicators you could use but a combination of variables such as max watts (not to be confused with ftp), VO2 max, efficiency etc. would give a more complete view of overall fitness.
  • reacher
    reacher Posts: 416
    He would have to clarify what he means, but i would think he used the phrase fitter as a generalization of who is the better rider, maybe, i don't know he asked the question.
    As i said its a very difficult concept to get your head around especially when you climb with someone as i do, who has nothing like my overall strength as regards muscular strength and yet can climb equally as well as i do by using a different gear/cadence ratio to achieve the same speed
  • The average power at end of a ride is essentially an average of the moment by moment (velocity x the sum of all resistance forces).

    If the velocity of two riders is precisely the same at all times, then for each to have finished the ride with a different average power means that the resistance forces for each rider was different.

    The various resistance forces in cycling include:
    air resistance,
    rolling resistance,
    drivetrain friction and bearing friction,
    inertial load when changing velocity, and
    gravity when ascending (and we reclaim gravitational potential energy when descending).

    No two riders will have exactly the same aerodynamics, experience exactly the same wind conditions (even ride side by side), have precisely the same rolling resistance, be the exact same weight nor have identical bicycle frictional factors.

    The above has nothing to do with fitness, which is an expression of what we are physiologically capable of (often relative to something and/or with a specific task in mind), rather than what we happen to have done on any particular ride.