Similar to heart zones, power zones are unique for each individual, yet unlike heart zones, there are no biological markers to clearly identify a person’s MSP (Maximum Sustainable Power) or ability to generate power. It is clear that both threshold heart rate and VO2 max are involved in generating power. The problem, however, is that these are neither predictive nor causative in their relation to this power. We therefore view them as ‘limiters’ or factors that can help us generate more power when they are improved (or hinder us in achieving our power goals if they are not suitably developed).
Consequently, we see heart zones and power zones as distinctly different constructs for training and they therefore do not follow the same structure. Power tends to be discussed in the context of how it is used, in increments of time (for the length of time that a given power level can be sustained). Most notably there are three distinct power intervals that provide the basis for the zones on our Power Zones Chart.
Thank you, Gene! This is a very informative article.