A step-by-step guide to performing and analyzing a heart rate drift test
Prepare for Your Workout
Before starting your heart rate drift test, follow these preparation steps:
Choose the right time: Perform the test when you're well-rested and haven't done intense exercise in the previous 24 hours. It is best to not have eaten in the 3 hours before the test. Avoiding high heat and humidity will also improve the accuracy of your test.
Select your target heart rate: Choose a heart rate that feels moderate - you should be able to maintain a conversation but feel like you're working. If you don't know where to start, your "MAF HR" (180-[your age]) is one option.
Gather your equipment: Make sure your heart rate monitor is fully charged and properly fitted. Arm or chest straps are preferred, but optical heart rate from a watch will work. If you do not have a heart rate monitor or smartwatch, you can purchase the Wahoo TICKR Heart Rate monitor (~$50) and connect it to the Wahoo Fitness App (compatible with both iOS and Android).
Plan your route: Choose a flat course to minimize pace variations due to terrain. Loops around parks, tracks, or long flat roads are ideal.
Perform the Test
During your heart rate drift test:
Warm up properly: Start with 10-15 minutes of easy running to get your body ready, ideally remaining at least 10 BPM below your target heart rate.
Maintain a steady heart rate: After your warm up, slowly increase your effort until you hit your target heart rate. Remain at this heart rate for one hour, allowing your pace to change as needed.
Avoid distractions: Focus on maintaining your target heart rate throughout the test. This will be boring.
Optional: cool down: After the one-hour test period, cool down with 10-15 minutes of easy running.
Upload Your Data
After completing your test:
Export your workout: Download your workout file (.fit or .gpx format) from your fitness device or app.
Upload to the analyzer: Use the file upload button on the main page to upload your workout file.
Select the test section: Use the sliders to select the one-hour test portion of your workout, excluding warm-up and cool-down.
Analyze your data: Click the "Analyze my test" button to process your data.
Interpret Your Results
The analyzer will provide you with several key metrics:
Average heart rate: For both the first and second half of your test.
Average pace: For both the first and second half of your test.
Pace-to-heart rate ratio: A measure of your efficiency that helps determine your aerobic threshold.
Percentage difference: The change in your pace-to-heart rate ratio between the first and second half.
Understanding Your Results
The percentage difference across the two halves of your test in your pace-to-heart rate ratio is the key metric for determining your aerobic threshold:
3.5-5% difference: This is the ideal range, indicating you've identified your aerobic threshold.
Less than 3.5% difference: Your target heart rate was below your aerobic threshold. Try the test again with a higher target heart rate.
More than 5% difference: Your target heart rate was above your aerobic threshold. Try the test again with a lower target heart rate.
If you have an inconclusive test, you can guess at your aerobic threshold by seeing how close you were to the 3.5-5% differene and roughly scaling your target heart rate up or down proportionally. For example, if your percentage difference was 5.2%, you may only need to move your target heart rate down by a few beats. Retest using that number to conrim it. Once you've identified your aerobic threshold, you can use this heart rate to set your training zones and optimize your endurance training.