Threshold Heart Rate - Run
What is Lactate Threshold Heart Rate (LTHR)?
LTHR is the heart rate at which lactate production and clearance reach a steady state during continuous exercise, typically estimated as the average HR over the final 20 minutes of a 30 minute maximal-run time trial.
Why measure LTHR?
Using LTHR to set training zones ensures prescribed intensities elicit the intended physiological responses: below threshold for aerobic development, at threshold to improve lactate clearance, and above threshold to boost VO₂ max and anaerobic capacity.
Performing your 30‑Minute Run Test
Warm up for 15–20 minutes, including easy jogging and a few short strides.
30 minute maximal effort: run at the highest steady pace you can sustain on flat terrain or a treadmill.
Cool down with 10 minutes of easy jogging.
Your average HR during the final 20 minutes closely approximates your LTHR.
Extracting your LTHR
On your GPS watch: start a lap at 10 minutes and end it at 30 minutes, then view the lap’s average HR.
In TrainingPeaks: upload your run, create a custom 20 minute split, and inspect the Average Heart Rate in the split summary.
Enter this LTHR into the calculator to generate your run‑heart‑rate zones.