Zo zie ik het ook matthijsln en lijkt me evident door de quote uit eerdergenoemde link. en elders ook te vinden:
'For example, a ride that has massive accelerations and then lulls (perhaps a criterium) will be more demanding on your energy systems than a ride that is much more steady – even though they may average out to being the same wattage in the end. Normalized Power is basically an estimate of the power that you could have maintainted for the same physiological “cost” if your power output had been constant. Because of the factors that are taken into consideration, Normalized Power gives you a better indication of the true demands of a ride than Average Power does.'
NP is dus eigenlijk min of meer een correctie welke, in geval van 'grote' pieken of dalen in vermogen het gemiddelde bijsteld om zo een betere schatting te maken (algorithme heb ik gezien en geloof op de Stages page) van de algehele belasting.
@53X11. zie
http://home.trainingpeaks.com/blog/arti ... ing-stress
Ik zie dat Alan meer details heeft gepost terwijl ik aan het schrijven en zoeken was.
Niet dat je dat zelf kunt toepassen of je Average Power maar het is het beste dat ik weet en kan vinden. Golden Cheetah doet het voor je.
Normalized Power (NP)
To account for this variability, TrainingPeaks uses a special algorithm to calculate an adjusted or normalized power for each ride or segment of a ride (longer than 30 seconds) that you analyze. This algorithm is somewhat complicated, but importantly it incorporates two key pieces of information: 1) the physiological responses to rapid changes in exercise intensity are not instantaneous, but follow a predictable time course, and 2) many critical physiological responses (e.g., glycogen utilization, lactate production, stress hormone levels) are curvilinearly, rather than linearly, related to exercise intensity.
By taking these factors into account, normalized power provides a better measure of the true physiological demands of a given training session - in essence, it is an estimate of the power that you could have maintained for the same physiological "cost" if your power output had been perfectly constant (e.g., as on a stationary cycle ergometer), rather than variable. Keeping track of normalized power is therefore a more accurate way of quantifying the actual intensity of training sessions, or even races. For example, it is common for average power to be lower during criteriums than during equally-difficult road races, simply because of the time spent soft-pedaling or coasting through sharp turns during a criterium. Assuming that they are about the same duration, however, the normalized power for both types of events will generally be very similar, reflecting their equivalent intensity. In fact, normalized power during a hard ~1 hour long criterium or road race will often be similar to what a rider can average when pedaling continuously during flat 40k time trial - the normalized power from mass start races can therefore often be used to provide an initial estimate of a rider's threshold power.
