The power zones described below were developed by fundamental principles of exercise physiology, and approximately two decades of experience with cycling training zones in laboratory and field settings. Some of the logic behind the development of this classification scheme is also described below.
Defining Cycling Power Zones
Power at lactate threshold (LT) is the most important physiological determinant of endurance cycling performance as it reflects VO2max, the percentage of VO2max that can be sustained, and cycling efficiency. Therefore, it’s more logical to define cycling training zones relative to an athlete’s threshold power rather than power at VO2max – just as it’s more logical to define HR-based training levels relative to threshold HR rather than maximal HR. However, determining the appropriate number of zones is somewhat arbitrary, as the physiological response to exercise falls on a continuum, with one intensity domain blending into the next.
A compromise must be made between defining more cycling power zones – to better reflect physiological differences – and fewer zones, for the sake of simplicity. In the present system, seven zones are felt to be the minimum needed to represent the full range of physiological responses and to adequately describe different types of training required (or used) to meet the demands of competitive cycling.
The tables below list the seven zones, plus the primary physiological adaptations expected to result from training at each zone. These will be influenced by factors such as the initial fitness of the individual, the duration of each workout, the time taken between each interval effort, etc.
Power-Based Training Zones (Coggan Power Zones)
| Level | Name | Average Power | Average HR | Perceived Exertion | Description |
| 1 | Active Recovery | <55% | <68 | <2 | “Easy spinning” or “light pedal pressure”, i.e., very low-level exercise, too low in and of itself to induce significant physiological adaptations. Minimal sensation of leg effort/fatigue. Requires no concentration to maintain pace, and continuous conversation is possible. Typically used for active recovery after strenuous training days (or races), between interval efforts, or for socializing. |
| 2 | Endurance | 56-75% | 69-83% | 2-3 | “All day” pace, or classic long slow distance (LSD) training. A sensation of leg effort/fatigue is generally low but may rise periodically to higher levels (e.g., when climbing). Concentration is generally required to maintain effort only at the highest end of the range and/or during longer training sessions. Breathing is more regular than at Level 1, but continuous conversation is still possible. Frequent (daily) training sessions of moderate duration (e.g., two hours) at Level 2 are possible (provided dietary carbohydrate intake is adequate), but complete recovery from very long workouts may take more than 24 hrs. |
| 3 | Tempo | 76-90% | 84-94% | 3-4 | Typical intensity of fartlek workout, ‘spirited’ group ride, or briskly moving paceline. More frequent/greater sensation of leg effort/fatigue than at Level 2. Requires concentration to maintain alone, especially at the upper end of the range, to prevent the effort from falling back to Level 2. Breathing deeper and more rhythmic than Level 2, such that any conversation must be somewhat halting but not as difficult as at Level 4. Recovery from Level 3 training sessions is more difficult than after Level 2 workouts, but consecutive days of Level 3 training are still possible if the duration is not excessive and dietary carbohydrate intake is adequate. |
| 4 | Lactate Threshold | 91-105% | 95-105%(may not be achieved during initial phases of effort(s)) | 4-5 | Just below to just above TT effort, taking into account duration, current fitness, environmental conditions, etc. Essentially continuous sensation of moderate or even greater leg effort/fatigue. Continuous conversation is difficult at best due to the depth/frequency of breathing. Effort sufficiently high that sustained exercise at this level is mentally very taxing – therefore typically performed in training as multiple ‘repeats’, ‘modules’, or ‘blocks’ of 10-30 min duration. Consecutive days of training at Level 4 are possible, but such workouts are generally only performed when sufficiently rested/recovered from prior training so as to be able to maintain intensity. |
| 5 | VO2 Max | 106-120% | >106% | 6-7 | Typical intensity of longer (3-8 min) intervals intended to increase VO2max. Strong to severe sensations of leg effort/fatigue, such that completion of more than 30-40 min total training time is difficult at best. Conversation is not possible due to often ‘ragged’ breathing. Should generally be attempted only when adequately recovered from prior training — consecutive days of Level 5 work are not necessarily desirable, even if possible. Note: At this level, the average heart rate may not be due to slowness of heart rate response and/or ceiling imposed by maximum heart rate) |
| 6 | Anaerobic Capacity | >121% | N/A | >7 | Short (30 s to 3 min), high-intensity intervals designed to increase anaerobic capacity. Heart rate is generally not useful as a guide to intensity due to the non-steady-state nature of the effort. Severe sensation of leg effort/fatigue, and conversation impossible. Consecutive days of extended Level 6 training are usually not attempted. |
| 7 | Neuromuscular Power | N/A | N/A | * (Maximal) | Very short, very high-intensity efforts (e.g., jumps, standing starts, short sprints) that generally place greater stress on musculoskeletal rather than metabolic systems. Power is useful as a guide, but only in reference to prior similar efforts, not TT pace. |
Expected Physiological and Performance Adaptations Resulting From Training in Zones 1-7
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |
| Increased plasma volume | ✔ | ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ ✔ ✔ | ✔ | ||
| Increased muscle mitochondrial enzymes | ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ ✔ ✔ | ✔ ✔ | ✔ | ||
| Increased lactate threshold | ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ ✔ ✔ | ✔ ✔ | ✔ | ||
| Increased muscle glycogen storage | ✔ ✔ | ✔ ✔ ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ | ✔ | ||
| Hypertrophy of slow twitch muscle fibers | ✔ | ✔ ✔ | ✔ ✔ | ✔ ✔ ✔ | ✔ | ||
| Increased muscle capillarization | ✔ | ✔ ✔ | ✔ ✔ | ✔ ✔ ✔ | ✔ | ||
| Interconversion of fast twitch muscle fibers (type IIb -> type IIa) | ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ | ✔ | ||
| Increased stroke volume/maximal cardiac output | ✔ | ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ ✔ ✔ | ✔ | ||
| Increased VO2 Max | ✔ | ✔ ✔ | ✔ ✔ ✔ | ✔ ✔ ✔ ✔ | ✔ | ||
| Increased muscle high-energy phosphate (ATP/PCr) Stores | ✔ | ✔✔ | |||||
| Increased anaerobic capacity (“lactate tolerance”) | ✔ | ✔ ✔ ✔ | ✔ | ||||
| Hypertrophy of fast twitch fibers | ✔ | ✔✔ | |||||
| Increased neuromuscular power | ✔ | ✔ ✔ ✔ |
Determining Lactate Threshold Power
At least in theory, the most precise way of determining an athlete’s power at LT would be to rely on laboratory-based testing with invasive blood sampling. Very few individuals, however, have access to such measurements. Sports scientists often define LT as the initial non-linear increase in lactate with increasing intensity. However, this intensity tends to be significantly lower than what coaches and athletes, based on practical experience, consider a “threshold” exercise intensity. Thus, probably the easiest and most direct way of estimating a rider’s functional threshold power is to simply rely on data collected in the field using a power meter.
Heart Rate Guidelines
Relating or translating the specified power zones to corresponding heart rate (HR) ranges or zones is somewhat difficult due to the inherent variability of HR. Plus, individual differences in the power/HR relationship (even when referenced to threshold power). Nonetheless, approximate HR guidelines have been provided in the table above and can be used along with power to help guide training if desired.
Perceived Exertion (PE) Guidelines
The values given are from Borg’s 10-point category-ratio scale (shown below), not the original 20-point scale that is more commonly used. The category-ratio scale is used because it explicitly recognizes the non-linear response of many physiological variables (e.g., blood and muscle lactate), providing a better indicator of overall effort. Since perceived exertion increases over time, even at a constant exercise intensity (power), the suggested values or ranges refer to the perceived effort as determined relatively early in a training session/series of intervals.
Borg’s 10-Point Category-Ratio Scale of Perceived Exertion
| Perceived Exertion | Description |
| 0 | Nothing at all |
| 0.5 | Extremely weak |
| 1 | Very weak |
| 2 | Weak (light) |
| 3 | Moderate |
| 4 | Somewhat Strong |
| 5 | Strong (Heavy) |
| 6 | |
| 7 | Very Strong |
| 8 | |
| 9 | |
| 10 | Extremely Strong |
| * | Maximal |
Other Considerations for Cycling Power Zones
While the system is based on the average power during a workout or interval effort, consideration must also be given to the distribution of power. For example, average power during mass start races typically falls within Zone 3, but races are often more stressful than training at Zone 3 due to the greater variability (and, therefore, higher peaks) in power.
Similarly, due to soft-pedaling/coasting, the same average power achieved during a hilly ride or group training session will not reflect the same stress as the same average power achieved during a completely flat ride or solo workout. In part, the variability in power is taken into account in defining the various zones, especially Zones 2 and 3 (training at the higher zones will tend to be much more structured, thus limiting variations in power). Furthermore, there is obviously an inverse relationship between power output and the duration that power can be sustained.
Overall, it’s axiomatic that power during shorter training sessions or efforts will fall towards the higher end of a given range, whereas power during longer sessions or efforts will fall toward the lower end of a given range. A workout consisting of, for example, 30 minutes of cycling at Zone 1 (as warm-up), 60 minutes of cycling at Zone 3, and another 30 min of cycling at Zone 1 (as warm-down) would best be described as a tempo training session, even though the overall average power might fall within Zone 2.
