A tool used by cyclists to determine training intensity ranges, often expressed as a percentage of Functional Threshold Power (FTP), helps structure workouts for optimal physiological adaptations. These ranges, typically five or seven zones, correspond to different metabolic demands and training effects, from active recovery to maximal efforts. A common example uses FTP to define zones; for instance, Zone 2 might be 56-75% of FTP, ideal for endurance building.
Structured training based on these personalized zones allows athletes to target specific physiological systems, maximizing training benefits while minimizing the risk of overtraining or underperforming. Historically, heart rate was the primary metric for gauging effort. However, power-based training offers a more precise and immediate measure of workload, reflecting changes in fitness and fatigue more accurately than heart rate, which can be influenced by external factors like temperature and stress.