When it comes to cycling performance metrics, Functional Threshold Power (FTP) and Critical Power (CP) often come up as tools for understanding and optimizing training. While both serve important purposes, they differ significantly in their origins, applications, and the insights they offer. Let’s break this down by tracing the history of these metrics and exploring their differences in a relatable and practical way.
The Origins of FTP
Functional Threshold Power was popularized by Dr. Andrew Coggan as a benchmark for cycling performance. FTP is defined as the maximum power a cyclist can sustain for approximately one hour. It has become a cornerstone of many training plans, serving as the basis for setting training zones and evaluating fitness.
Think of FTP as the "fuel efficiency" indicator in a car. It represents how well you can maintain a steady output over a specific duration. However, FTP is derived from an estimation, often requiring a 20-minute test with adjustments, and it assumes a consistent relationship between effort and duration.
Limitations of FTP
Fixed Duration Dependency: FTP is tied to a one-hour effort, which may not represent performance across shorter or longer durations.
Simplistic Estimation: The 20-minute test used to calculate FTP involves adjustments that may not fully account for individual variability.
Limited Insights into Energy Systems: FTP does not provide detailed information about the balance between aerobic and anaerobic contributions.
The Origins of Critical Power
Critical Power, on the other hand, emerged from exercise physiology research as a measure of sustainable performance. CP is the maximum power output a cyclist can sustain indefinitely without fatigue from lactate accumulation—theoretically speaking, of course. In practice, CP is derived from multiple time-trial efforts and represents the boundary between aerobic and anaerobic energy systems.
Using the car analogy, Critical Power is like the "engine power" indicator. It tells you how much consistent performance your engine can deliver without breaking down. Unlike FTP, which is tied to a fixed duration, CP is more dynamic and reflects your physiological capabilities across various time frames.
Strengths of Critical Power
Dynamic Measurement: CP accounts for performance across multiple durations, offering a more nuanced view of capabilities.
Energy System Insights: CP reflects the boundary between sustainable and unsustainable efforts, aiding in training precision.
Adaptability: It’s useful for pacing strategies and tailoring training to specific needs.
Key Differences Between FTP and CP
To further clarify the differences, let’s visualize them with a car metaphor:
FTP (Fuel Efficiency):
Fixed-duration measure (approximately 1 hour).
Represents steady-state performance.
Useful for setting training zones and comparing fitness over time.
Critical Power (Engine Power):
Dynamic measure across multiple durations.
Indicates sustainable performance over time.
Useful for pacing strategies and understanding fatigue thresholds.
Why Vekta’s Focus on CP Matters
By prioritizing Critical Power, Vekta shifts the focus from static benchmarks to dynamic, individualized training. CP encourages athletes to understand their physical limits and train strategically to improve them. It’s not just about analyzing what happened; it’s about shaping what’s possible.
In conclusion, understanding both metrics—and their differences—is key to optimizing performance. While FTP offers a standardized view of fitness, Critical Power provides a flexible, adaptable framework for training. Think of CP as a forward-thinking tool in your cycling toolbox, capable of driving your performance to new heights.

Ulisses Nunes Abbud
USA Cycling Certified Coach