Reviewed by: David Chen, Ph.D. (Exercise Physiology)
Accurately estimate your Lactate Threshold Heart Rate (LTHR) and Lactate Threshold Pace (LTPace) based on the results of a maximal steady-state field test, such as a 30-minute time trial.
Lactate Threshold Calculator
Your Estimated Lactate Threshold (LT) Values
LT Heart Rate: N/A BPM
LT Pace: N/A min/km
Detailed Calculation Steps
Fill in the inputs and click Calculate to see the steps.
Lactate Threshold Formula
The calculation is based on the results of a maximal, steady-state field test, such as a 30-minute time trial (TT). The estimated Lactate Threshold is generally taken as the average heart rate and pace maintained during the last 20 minutes of a 30-minute TT.
Estimated LTHR (BPM) = Average Heart Rate from Test
Estimated LT Pace (Min/Km) = Average Pace from Test
Formula Sources: TrainingPeaks – LTHR Field Test Protocol, Fellrnr – LT Heart Rate Estimation
Variables
- Average Heart Rate (BPM): Your average heartbeats per minute recorded during the test period. This is the estimated Lactate Threshold Heart Rate (LTHR).
- Average Pace (Minutes per Kilometer): Your average running pace during the test. This is the estimated Lactate Threshold Pace (LTPace).
- Test Duration (Minutes): The total time of your field test. Must be at least 20 minutes for a reliable estimation.
What is Lactate Threshold?
Lactate Threshold (LT), often referred to as Maximal Lactate Steady State (MLSS), is the point during exercise where lactate begins to accumulate in the bloodstream faster than it can be removed. This point signifies the maximum effort level you can maintain for an extended period without fatiguing rapidly.
In endurance sports, knowing your LT is crucial because it allows you to define your training zones and race intensity. Training near or slightly above your LT is a highly effective way to increase endurance and performance, teaching your body to clear lactate more efficiently.
While lab tests involving blood samples are the most accurate, field tests (like the 30-minute time trial used here) provide a highly reliable estimate of your LT heart rate and pace, which can be easily measured and used in training.
How to Calculate Lactate Threshold (Example)
Let’s use an example to show how the calculation is performed:
- Perform the Test: An athlete completes a 30-minute maximal steady-state run.
- Record Data: The athlete records an Average Heart Rate of 178 BPM and an Average Pace of 4.15 minutes per kilometer. The Test Duration was 30 minutes.
- Validate Duration: The duration (30 minutes) is greater than the required 20 minutes for a reliable estimate.
- Determine LTHR: The estimated Lactate Threshold Heart Rate (LTHR) is the average heart rate during the test, which is 178 BPM.
- Determine LT Pace: The estimated Lactate Threshold Pace (LTPace) is the average pace during the test, which is 4.15 min/km.
Related Calculators
- Maximal Heart Rate (MHR) Calculator
- Training Zone Calculator
- Running VDOT Score Estimator
- BMR & Calorie Needs Calculator
Frequently Asked Questions (FAQ)
A: The 30-minute test is widely used because the pace and heart rate you can sustain for that duration closely approximate your Maximal Lactate Steady State (MLSS), which is synonymous with your Lactate Threshold.
A: It is recommended to retest every 4 to 8 weeks, especially during periods of high-intensity training, as your LT values can improve quickly with proper training stimulus.
A: While the 30-minute test is standard, any maximal steady-state effort lasting between 20 and 40 minutes can provide a reliable estimate, provided you are at maximal sustainable effort.
A: While often used interchangeably, Lactate Threshold (LT) is a specific physiological measure of lactate accumulation. Anaerobic Threshold (AT) is a broader term referring to the shift from predominantly aerobic to predominantly anaerobic metabolism.