The “Watts up with Power?” ride is likely the slowest group ride you’ll find on Zwift, because it focuses on learning the basics of power based training while riding together on Zwift. Each ride is streamed to Zwift LIVE by ODZ on Facebook, and focuses on teaching specific principles of power-based training. For viewers that are unable to attend live, the teaching is made available for all to review afterwards.

Here is the summary for April 5 from ride leader Nate Dunn.


Training w/Power:  The Why

There are a ton great reasons to train with power.  Track fitness, analyze race performance, guide sports nutrition decisions, the list goes on.  Today we’re focusing on how a better understanding of the science behind power can help you create a more measurable, process-based approach to your training.

A Process-Based Approach

A better training process starts with an understanding of the lactate threshold (LT).  Put simply, the LT is “the point at which your body can no longer maintain equilibrium between lactate production and clearance.”  Why does the LT matter?  In short, it’s the best measure we have of endurance performance.  So how do you measure and track your LT?

Typical Lab Test

A classic LT test involves executing a basic ramp protocol on a stationary bike in a laboratory.  Ride intensity is increased every minute while blood lactate samples are taken at fixed intervals.  The point at which blood lactate begins to rise sharply (generally around 4 mmol/L) is cross referenced with your power output on a curve.  This “deflection point” of blood lactate along with your power output is defined as your “power at lactate threshold.”

Making LT “Functional”

The laboratory is a great place to objectively measure blood lactate levels but doesn’t serve as a very functional way to routinely and dynamically track fitness.  Enter the mobile exercise physiology laboratory, the power meter.  So how do we translate the 4 mmol/L threshold to power on the bike?  A few ways.  A cyclist’s laboratory defined power at LT is generally comparable to these “functional” power meter measures.

  • Average power over a 40k TT
  • Average power for 60m all-out TT
  • 20m peak power less 5-15%
  • 60m peak normalized power (NP)

In summary, the lab is interesting but a power meter on your bike is infinitely more functional and useable in day to day training.  We’ve arrived at FTP, or Functional Threshold Power.

A Power-Based Process

So what does a power-based process look like?  First, understand where FTP comes from, its origin in exercise science, and why it matters to your cycling.  Second, develop specific, power-based goals.  Third, track your progress.  And finally, evaluate your goals making adjustments to your training as needed.