Normalized Power and Variability

Normalized Power and Variability

Normalized Power accounts for the variable nature of cycling efforts and their physiological cost.

Why Normalized Power Matters

• Average power doesn't tell the full story
• Surges and hard efforts cost more than steady riding
• 200W steady ≠ 200W average with variation
• NP better reflects actual physiological demand

Variability Index (VI)

• VI = Normalized Power ÷ Average Power
• 1.00-1.05: Very steady (time trial, climbing)
• 1.05-1.10: Relatively steady (tempo ride)
• 1.10-1.20: Variable (criterium, group ride)
• 1.20+: Very variable (attacks, steep hills)

Applications in Racing

• Time trials: Target VI < 1.05 for optimal pacing
• Criteriums: VI often 1.20+ due to corners and attacks
• Road races: Monitor NP to avoid burning matches
• Training: High VI workouts (VO2max) vs low VI (threshold)

Intensity Factor (IF)

IF = Normalized Power ÷ FTP. Indicates relative intensity of effort. IF of 1.0 = riding at FTP. IF > 1.0 is above threshold (unsustainable long-term). Use IF to ensure you're training in intended zones.