A lactate test can be performed as an additional feature of a load screening on a treadmill.
In the PRO platform, click the OnTracx Lab symbol on the left.
You’ll be redirected to the Lab environment.
Click Start a test.
Select Screening Type:
Load Screening
toggle on the Add-on: Performance testing
Lactate testing is currently only available on Treadmill.
Test Configuration:
Single leg – select left or right (preferably the injured or target leg).
Both legs – measure load on both legs for asymmetry insights (requires two sensors and is only available on Treadmill).
Choose Athlete: Select an athlete from your list.
Execute Test
The Execute Test screen has four quadrants:
Upper Left: Speed Selection: Indicate the running speed for the athlete.
Upper Right: Sensor Connection & Real-Time Load
Tap Connect Sensor to open the connection screen.
Enable Bluetooth if it’s your first time connecting.
Wake up the sensor – touch both metal pins on the back simultaneously for <1 second.
Select your sensor by checking the unique ID on the back.
For asymmetry tests, connect two sensors and ensure each sensor is attached to the correct leg.
When active and in pairing mode, the red LED stays on continuously. After 1 minute, the sensor enters standby; briefly press both pins again to wake it up.
Lower Left: Measurement Periods
Press Start to begin measuring.
The sensor will record continuously, but only the indicated measurement period is used for data analysis.
After the period ends, the average load will appear in the Lower Right Quadrant as a new data point.
Fill out heart rate, lactate value and RPE score.
Repeat this process for multiple speeds. Make sure to record data at a minimum of three different speeds to ensure a reliable analysis.
Once finished, click Finish Test to stop the sensor.
Data is stored on the sensor and can be synced to the athlete’s profile in the OnTracx app. Make sure to clear sensor data regularly!
Once the lactate screening is complete, the analysis at the bottom of the page shows how the athlete’s load and how lactate and heart rate varies across speeds.
Three key thresholds are calculated:
Aerobic Threshold (LT1): The point where lactate begins to rise ~0.5 mmol/L above baseline.
Anaerobic Threshold (LT2): Determined using the Dmax method, this is where lactate starts increasing rapidly.
Load Breakpoint: The point on the load curve where the rate of increase changes, indicating a shift in running mechanics. The slope values show how much additional load is experienced per km/h as speed increases.
Load generally rises with speed, but the pattern differs per athlete: some show a steady, linear increase, while others show a breakpoint effect, where load increases more sharply after a certain speed. Identifying this speed-load breakpoint is essential: running above it may cause disproportionately high loads, while staying below it supports safer, gradual progression—especially during rehabilitation.
Using these thresholds, training zones are defined based on both physiological (lactate) and biomechanical (load) metrics. This allows you to design an optimized training plan that considers not only speed and endurance but also the mechanical load experienced by the athlete, ensuring safer and more effective progression.
You can generate a report in pdf or as raw data to integrate in your own template and share it with the athlete.