Power Meters for Cycling

Training and Racing with a Power Meter

• Power = the amount of energy being applied to the pedals.
• A function of torque (pressure on the pedals) and cadence.
• Provides immediate feedback on cycling effort.
• Does not have the lag effect that heart rate does.
• Is not affected by wind, gradient, temperature, fatigue, hydration etc that other indicators like Speed and HR are.

Functional Threshold Power (FTP)

• FTP is defined as the average power that an athlete can maintain for a 1 hour effort.
• All training and racing zones should be expressed as a % of your FTP.
• FTP can be determined in a number of ways:
  – 1 hour TT average power eg. 260w
  – 20min TT average power ÷ 1.05 eg. 273w over 20min = 260w for 1 hour
  Your FTP should be retested every 4-6 weeks to recalibrate training zones

Training with a Power Meter

Power based training levels (zones) are developed based on your FTP. Coggan based training zones:

Zones are used for targeted physiological and performance adaptations

Typical Workouts for Power Based Training

Power and Heart Rate

Power and heart rate will not always track together. Fatigue, dehydration, tiredness will increase HR compared to power. In training or racing, this is called ‘decoupling’.

Important Data from the Power Meter

 

Analysing the Data

• Use lap splits to allow easier power workout analysis.
• Consistent Normalised Power from lap to lap, 5% variance.
• Low Variability Index, < 1.05
• Low decoupling ratio < 5%
• Get a feeling of the level of fatigue for a given TSS.

Racing with a Power Meter

• Establish your goal race power using formula.
• Expect high power at the start but try to keep it down – PACING!
• For an undulating course, aim to hold 95% of goal power on flats.
• For a >3min hill, ride at 105% of goal wattage.
• For a <3min hill, ride at 110-120%
• Expect decoupling of power and HR.
• Aim for each lap to be as close to target power as possible.
• Avoid surges, and power spikes.