As endurance athletes and coaches, we often become fixated on finding our precise training thresholds. Whether it's lactate threshold, ventilatory threshold, or muscle oxygen saturation (SmO2) breakpoints, we chase these numbers as if they're the holy grail of performance. But what if I told you that the exact threshold number isn't what matters most?
Thresholds are signposts, not destinations
Think about driving to a new location. You might get directions like "turn left at the giant oak tree." That oak tree doesn't get you to your destination—it simply helps you navigate. Similarly, physiological thresholds are navigational tools that help us understand where we are in our training journey.
Thresholds aren't causal—they're merely indicators of physiological transitions. They show us where our body shifts from one predominant energy system to another, or where our muscles begin to desaturate oxygen at a different rate. These transition points help us organize our training into zones that target specific adaptations.
How does adaptation to training work?
Imagine endurance adaptation as a string anchored at two points: rest and an all-out sprint. If you lift that string somewhere in the middle, you'll create a crest. The highest adaptation point will occur around where you lifted, with a gradual slope extending in both directions.
This is exactly how training adaptations work. If you train near your first or second threshold, you'll see the greatest adaptations around those intensities—but you'll also see some adaptation across a wider range. The exact threshold number becomes less important when you realize that getting close is often good enough to drive the desired adaptations. But, this doesn’t mean we should continue to measure thresholds regularly.
How to use thresholds as monitoring tools?
One of the most valuable aspects of threshold measurements is their ability to track changes over time. They serve as anchor points that allow us to monitor our progress. When you see your thresholds shifting upward over weeks and months, you know your training is working.
This is where consistent testing becomes valuable. By regularly assessing your thresholds using the same protocol—whether through a Moxy Monitor assessment or other methods—you create comparable data points that reveal your physiological development.
Why should you keep measuring your thresholds?
The true value of threshold measurements isn't in the exact numbers but in what they tell us about our physiology and how we can use that information to train more effectively. Thresholds help us understand the continuum of exercise intensity and provide benchmarks to track our progress.
Want to learn more about how to measure and use thresholds to optimize your training? Download our comprehensive Training and Racing with Moxy eBook to gain deeper insights into leveraging muscle oxygen data for enhanced performance.
