May 2, 2025

If you’re a runner or cyclist, you know how important pace is — especially on longer runs or rides. Push yourself too hard and too soon, and you run the risk of not being able to finish.

Paying attention to your lactate threshold could help. Here’s how.

What is lactate threshold?

Your lactate threshold is the point where your muscles begin to fatigue quickly when exercising.

Your body produces lactate when breaking down carbohydrates for energy, according to the Cleveland Clinic. Before reaching your lactate threshold, according to the American Council on Exercise, your body balances between producing and removing lactate.

But at this threshold, lactate (or lactic acid) begins accumulating in your bloodstream. When you exceed your lactate threshold, you may get tired faster, and your ability to keep your pace may drop.

For example, let’s say a marathon runner’s pace is about 5% below their lactate threshold. If they push 5% above their lactate threshold, they may only be able to keep up that pace for about 20 minutes.

Experienced runners may see a lactate threshold occur around 90% of their maximum heart rate and between a 10K to a half-marathon race pace. The lactate threshold for beginner runners is typically well below that.

Oh, and don’t blame your muscle soreness on lactate buildup — that’s actually a myth. (You can usually pin the blame on tiny tears in muscle fibers). But while you wait for the soreness to pass, you could try a yoga or mobility workout available on the Garmin Connect^™ app to help while monitoring your recovery time countdown on your Garmin smartwatch.

How does Garmin use lactate threshold to help you train?

Compatible Garmin devices use advanced analytics, which include factors such as your VO2 max estimate, heart rate¹ and recent run pace data, to interpret your performance and estimate your lactate threshold. When you run, your lactate threshold is expressed in pace (minutes per kilometer or minutes per mile), corresponding heart rate and power.

Garmin Run Coach and Garmin Cycling Coach, adaptive training programs that can help you achieve a personal milestone or train for a race, account for your lactate threshold when adjusting workout intensity and targeting training outcomes. These workouts fit into one of three categories: low-intensity aerobic workouts, high-intensity aerobic workouts and anaerobic workouts. Threshold workouts, in the high-intensity aerobic category, aim to improve your ability to run at — and raise — your lactate threshold.

Plus, the real-time stamina feature uses your lactate threshold to model fatigue and how much you have left in the tank. And when you’re training for a race, your lactate threshold helps refine race-time predictions.

When you’re training by heart rate zones based on a percentage of your maximum heart rate, spending time in zone 4 (where you’re exercising intensely at an uncomfortable pace) can help you improve your lactate threshold. You can also set up your heart rate zones based on a percentage of your lactate threshold heart rate. Your lactate threshold then becomes the boundary between zone 4 and zone 5.

If you’re ready to go the distance and train your lactate threshold, browse our collection of multisport smartwatches today.

_{¹See Garmin.com/ataccuracy}