Is tracking power-to-heart rate ratio in Zone 2 truly worth the investment for recreational cyclists, or are we just drinking the Kool-Aid pushed by the endurance training industry? What tangible benefits can be expected from closely monitoring this metric, and how does it compare to simply tracking perceived exertion or heart rate alone? Are there any actual studies that demonstrate improved performance or reduced injury risk as a direct result of this type of monitoring, or is it just another form of techno-voodoo thats more likely to confuse than clarify? And for those who swear by this method, how do you account for individual variability in power output and heart rate, not to mention the potential for inaccurate or inconsistent data?