The Cycling Power is firstly a mechanic value before to be considered as a performance indicator.
The rider need to overcome five principal elements ; the most important of these elements (on flat terrain) is the aerodynamic drag.
For a 30Km/h speed we could consider than more 80% of the power developed by the rider is due to air resistance.
The power (expressed in watts) is the amount of Torque generated at the pedals multiplied by the angular velocity of the pedals.
The torque depends of how hard you push the pedal and of tour pedaling technique.
The angular velocity depends directly of the cadence.
To sum up, the Cycling Power is related to :
- the muscular effort on the pedals
- the cadence
- the pedaling technique
Focusing of this concept, you can note that it’s possible to develop the same amount of power with different ways : (Big gear/ low cadence or medium gear/High cadence).
Measuring you power is measuring directly the level of effort you’re doing : it’s your live effort !
Before powermeters, the most accurate training tool was the Heart Rate Monitor.
The maion advantage of Heart rate Monitor was the download function for analysis. This was the first time that you could see after the training of the race a full description of your session.
The weak point of Heart Rate when you have to manage your pace during a race or when you have to target a specific effort during interval training is that the increase of heart rate is only a body answer => the HR always increase after the beginning of your effort.