Skip the Lactate Strips. Guide Your Threshold Running with Stryd.

Traditional lactate threshold testing requires blood samples from specialized equipment, controlled environments, and breaks within a workout, which makes it expensive and unrealistic for most runners.

But threshold training is still one of the most important parts of endurance performance. Knowing your first lactate threshold (LT1) and second lactate threshold (LT2), the points that separate easy, moderate, and hard effort, helps make training more accurate and effective.

A new peer-reviewed study from the University of Western Ontario, published in the International Journal of Sports Physiology and Performance, provides direct lab-based evidence that Stryd running power reflects the same threshold boundaries whether runners are on flat ground or climbing at grades up to 10%. This suggests that running with Stryd-based power may offer a more practical path to accurate threshold training than the traditional speed-based alternative.

Here’s a closer look at what the researchers found.

What the Researchers Did

Researchers tested 13 highly trained runners using max treadmill tests at three different inclines: 0%, 5%, and 10%. Intensity was continually increased every 3min in each test and was matched for running power output using Stryd.

The higher the test incline that day, the more the runners would slow down to maintain the same target power. Throughout the test, researchers measured oxygen uptake (VO₂), blood lactate concentration, heart rate, and running power at the end of each 3min stage.

The goal was simple: determine whether the power output associated with LT1 and LT2 stayed consistent as the incline changed between tests.

What They Found

The key finding is that running power at both LT1 and LT2 was statistically unchanged across all three treadmill inclines. VO₂ at both thresholds also stays consistent between conditions.

In practical terms, runners reach the same physiological thresholds at roughly the same power output whether they are on flat ground or climbing at 10%.

That matters because pacing by speed alone cannot do this. As the incline increases, running speed drops significantly, but the physiological response associated with a given power output stays remarkably stable.

Why This Matters

This study suggests that Stryd running power may provide a more practical way to estimate and monitor those same lactate thresholds. The findings indicate that threshold power values identified through Stryd are likely to remain meaningful as gradient changes, meaning runners can use power to track effort consistently across different terrain without requiring repeated testing every time their training environment shifts.

Additionally, with lactate testing people are usually just using average references (i.e. 4mmol for LT2) but threshold running with Stryd can be personalized based on individual power target. Power lets you take the hassle out and lets you know you're hitting the right intensity in real time, not after a rep when it's already too late.

Less testing. Less cost. Less guesswork.

The Bigger Picture

The biggest takeaway is not just that power stays consistent uphill.

It is that research like this continues to build the case for Stryd running power as a more accessible way to monitor training intensity across changing terrain. For trained runners, the evidence suggests that threshold power values identified through Stryd are likely to remain meaningful across the gradients most runners encounter, without requiring repeated testing at every new incline.

For most runners, that could be the difference between guessing and truly training with purpose.

Tap the button below to read the full study from the International Journal of Sports Physiology and Performance.