NP
Normalized Power
Normalized Power (NP) represents the physiological 'cost' of a variable-intensity ride. Learn how NP is calculated and why it's more meaningful than average power.
Quick Answer
NP — Normalized Power (NP) is a weighted average power that accounts for the greater physiological cost of variable-intensity riding. Unlike average power, NP reflects how hard a ride actually felt by giving more weight to harder efforts.
What Does Normalized Power Mean?
Normalized Power estimates the power you would have needed to hold steadily to produce the same physiological stress as your actual variable ride.
Consider two rides with the same average power of 200W:
- Ride A: Steady 200W for 1 hour
- Ride B: Alternating 300W and 100W for 1 hour
Both have 200W average, but Ride B feels much harder because the high-power surges create more stress. Normalized Power captures this difference.
NP is essential for calculating TSS and Intensity Factor.
How NP is Calculated
The algorithm developed by Dr. Andrew Coggan:
Step-by-step process:
- Calculate 30-second rolling average power
- Raise each value to the 4th power
- Average all the values
- Take the 4th root of the result
Formula:
NP = ⁴√(average of (30-second rolling average)⁴)
Why the 4th power? It approximates how your body responds to intensity changes—harder efforts cost disproportionately more than easier ones.
NP vs Average Power
| Scenario | Average Power | Normalized Power | Difference |
|---|---|---|---|
| Steady indoor ride | 200W | 202W | ~1% |
| Flat outdoor ride | 200W | 210W | ~5% |
| Hilly ride | 180W | 220W | ~22% |
| Group ride with surges | 170W | 230W | ~35% |
| Criterium race | 150W | 280W | ~87% |
The more variable the effort, the larger the gap between average and normalized power.
Why NP Matters
1. Accurate Training Stress
NP enables accurate TSS calculation:
TSS = (Duration × NP × IF) / (FTP × 3600) × 100
Using average power would underestimate training stress for variable rides.
2. True Intensity Measurement
Intensity Factor (IF) = NP / FTP
This tells you how hard the ride was relative to your threshold—essential for training prescription and pacing.
3. Pacing Analysis
Comparing NP across race segments reveals:
- Energy expenditure patterns
- Pacing consistency
- Potential areas for improvement
Interpreting NP Values
NP Relative to FTP
| IF (NP/FTP) | Ride Type | Sustainable Duration |
|---|---|---|
| 0.55-0.75 | Easy/Endurance | 3-6+ hours |
| 0.75-0.85 | Tempo | 2-4 hours |
| 0.85-0.95 | Sweet Spot | 1-2 hours |
| 0.95-1.05 | Threshold | 45-60 minutes |
| 1.05-1.15 | Race pace | < 45 minutes |
| > 1.15 | Short race/TT | < 30 minutes |
NP for Different Events
| Event | Typical NP as % FTP |
|---|---|
| Century ride | 65-75% |
| Gran Fondo | 75-85% |
| Road race | 85-95% |
| Criterium | 90-110% |
| Time trial | 100-105% |
| Short track race | 110-120% |
NP and Race Pacing
The Pacing Problem
Surges cost more than steady riding. A rider who goes 20% above and 20% below their target power:
Target: 250W
Actual: 300W × 50% + 200W × 50% = 250W average
NP: ~265W (higher due to surges)
The surges mean this rider expends energy equivalent to holding 265W steady, not 250W.
Optimal Pacing Strategy
For time trials and triathlons, minimize power variability:
- Keep power within ±5% of target
- Avoid big surges (even if you feel good early)
- Use power smoothing to reduce NP/Average gap
Read our Cycling Pacing Strategy Guide.
Variability Index (VI)
The ratio of NP to Average Power:
Variability Index = NP / Average Power
| VI | Interpretation |
|---|---|
| 1.00-1.02 | Very steady (trainer, TT) |
| 1.02-1.05 | Steady outdoor ride |
| 1.05-1.10 | Moderate variability |
| 1.10-1.20 | Variable (group ride, hills) |
| > 1.20 | Highly variable (racing, crits) |
For time trials, aim for VI < 1.05. Higher VI indicates energy "wasted" on variability.
Common Questions
Is higher NP better?
Not necessarily. Higher NP means more stress, which is good for training adaptation but also requires more recovery. The goal is appropriate NP for your training objectives.
Why is my NP higher than FTP on some rides?
Short, hard efforts can produce NP above FTP. This is normal for:
- Races (especially short ones)
- High-intensity interval sessions
- Criteriums and group rides
The key is whether you can sustain that NP—if the ride is > 1 hour, NP should typically be at or below FTP.
Does NP work for running?
Running uses Normalized Graded Pace (NGP) instead, which accounts for terrain but works on similar principles. The physiological stress of variable running paces is captured differently due to the nature of running.
Why is my NP lower indoors?
Indoor trainers typically produce steadier power (no coasting, consistent resistance), resulting in closer NP to average power. This doesn't mean the ride was easier—it was just more consistent.