A ripple effect conceptualization of the power-duration curve

By Steve Palladino

Palladino Power Project

August 21, 2017

To some degree, training impact and training emphasis are like the ripple effect seen after dropping a pebble into a pond.  The wave propagates away from the point of impact, gradually working away from the point of impact in all directions, diminishing in magnitude as the wave moves more distant from the point of impact.

Training impact

Consider the impact point of the pebble in the pond like a workout target on one’s personal power-duration curve.  The maximal effect on the power-duration curve is at the target focus of the workout.  However, the workout also has an impact on the athlete’s power-duration curve beyond the point of impact or focus of the workout.  The impact is felt greatest on the areas of the power-duration curve closest to the focal point of the workout.  The impact on other areas of the power-duration curve further from the focal point of the workout diminishes as the distance progresses away (both to the right and to the left) on the power-duration curve.  

Now let’s look at the same photo with a hypothetical power-duration curve superimposed (below).  Imagine that the workout target was at the 9-10 minute point of the power-duration curve.  Effects on the curve can be imagined rippling outward, but in diminishing magnitude of effect.

Training emphasis

So too, does the analogy apply to the emphasis in a training program geared for a race at a particular point on the power-duration curve.  Using the above photo again, but this time to emphasis the analogy in terms of training emphasis, one can imagine the relative distribution of overall training emphasis in a build to, say, a 5k race, to follow similarly.  The maximal overall emphasis will, in the end, be placed closest to the race target power-duration.  Other points along the power-duration curve will be worked, but to progressively lesser degrees as the focus of the work is located further away (to the right and the left) on the power-duration curve.  

The following photo is another analogous depiction - this time of a) the training effect of an approximately 1h20m run at 88% of FTP and b) the training emphasis that might be adopted for a half marathon.

One might think that the principle of individuality may impact the concept.  Likely so, but consider that one’s power-duration curve typically accurately reflects the individual’s strengths and weakness - it embodies individuality.  Perhaps individuality may reflect how far the “effect” propagates on the power-duration curve, and perhaps even asymmetric directionality of the effect.  Heck, if the athlete is a non-responder to a particular stimulus, it might be as if the pond is frozen, and the chosen pebble does not even penetrate the surface, much less create a ripple effect. Other factors influencing the translation of the concept to reality might also include a) periodization, b) the absolute magnitude of training emphasis along the power-duration curve, and c) the time course for adaptations at various points along the power-duration curve, and the rate of regression of these adaptations.

Nevertheless, I find the concept and visual depiction an important aspect of understanding the power-duration curve.