FTP (Functional Threshold Power) refers to the power level a rider can sustain for a long duration under a state near lactate steady-state, and is commonly used as a core indicator to evaluate endurance performance and training intensity. Through FTP, riders can convert power output into quantifiable and comparable training zones, helping to plan training content and track changes in physical fitness.
On Bryton bike computers, FTP zone-related data must be used in conjunction with a power meter. Simply set your personal FTP value in the Bryton Active App, and the bike computer will automatically calculate each zone based on the FTP and display the current output status in real time while riding, making training interpretation more intuitive. Below is an explanation of the common FTP zone data found on Bryton bike computers.
1. FTP Zone
The FTP Zone represents which FTP percentage range your current power output falls within, such as 60–70%, 80–90%, etc. In practical application, this data can be used to confirm in real time whether the current training intensity matches the originally set target. For example, during an endurance ride, by observing the FTP Zone, you can ensure that power is maintained within a lower intensity zone, preventing you from inadvertently entering an excessively high load.
2. Time in FTP Zone 1~7
Time in FTP Zone 1~7 represents the accumulated length of time spent in each FTP zone throughout the entire ride. This data is primarily used for post-ride analysis to help understand the distribution of overall training intensity. For example, if most of the time is concentrated in the low-to-medium intensity zones, it represents that this training session was primarily focused on endurance; if the proportion of high-intensity zones is on the higher side, it may belong to a training session with higher intensity content.
FTP Zone Classification (Based on FTP Percentage)
-
FTP Zone 1 (< 55% FTP): Belongs to the recovery zone, with extremely low intensity, suitable for warm-ups, cool-downs, or recovery rides.
-
FTP Zone 2 (56–75% FTP): Endurance zone, primarily used to build an aerobic base, suitable for long-duration steady output.
-
FTP Zone 3 (76–90% FTP): Tempo zone, situated between endurance and high intensity, capable of elevating aerobic capacity and steady output performance.
-
FTP Zone 4 (91–105% FTP): Threshold zone, close to your personal FTP level, primarily training the ability to maintain steady output under high intensity, which is quite critical for elevating endurance performance.
-
FTP Zone 5 (106–120% FTP): High-intensity zone, belonging to an output range that can be sustained for a short duration, commonly used in interval training to elevate high power output capacity and adaptation to lactate accumulation.
-
FTP Zone 6 (121–150% FTP): Extremely high-intensity zone, where output duration is typically quite short, making it more suitable as an intensity prompt and reference for short interval training.
-
FTP Zone 7 (> 150% FTP): Explosive output zone, belonging to instantaneous power performance, primarily reflecting sprinting and neuromuscular output capacity.
How to Calculate FTP?
Common methods for setting FTP include:
-
20-Minute FTP Test Method: Perform an all-out steady output for 20 minutes, taking 95% of the average power as the estimated FTP value.
-
Ramp Test: Power is progressively increased until pedaling can no longer be sustained; the system automatically extrapolates the FTP based on the test results.
-
CP20 Test (20-Minute Critical Power Test): Identical in concept to the 20-minute test method, it uses the average power from an all-out 20-minute output multiplied by 0.95 to estimate your personal FTP.
Important Reminders for Use
Due to the physiological characteristics of the cardiorespiratory and muscular systems, the training and analysis of FTP zones are mostly concentrated within zones 1 to 5. When the output intensity exceeds higher percentages of FTP, the time that power can be sustained is extremely short, and the reference value of relying solely on FTP as an interpretation basis decreases relatively. Therefore, FTP zones 6 and 7 typically only serve as intensity prompts and auxiliary observations; for actual high-intensity and explosive training, it is recommended to interpret them alongside the power curve, cadence, or speed data.
Conclusion
The value of FTP zones lies not in chasing the "zone numbers themselves," but in helping riders convert power output into an understandable and controllable training intensity. As long as you first set your FTP correctly, and observe it alongside the FTP Zone and the time within each zone, you can more clearly master your training focus, giving every ride more direction and making it easier to accumulate substantial progress.