This is one of several articles describing different testing protocols for running. These tests are appropriate for triathlete as well as for runners. This test is for determining your estimated Threshold Heart Rate. If you’d like to determine your threshold running paces, visit the Running Pace Training Zone Calculator. Or return to our main Training Calculators Page.
20 Minute Protocol for Running Threshold Heart Rate
This is a twenty-minute field test protocol used to determine your “threshold heart rate” and pace. Knowing your threshold heart rate will help you both plan workouts as well as to measure progress in your training.
Field Test Warmup
A good running warmup serves several purposes in both training as well as racing. Your muscles need time to both warm-up physically as well as “wake up” neurologically. When you start an activity, your body recruits only the smallest amount of muscle to get the job done. Why? Because you are an efficient human being! The body only uses as much energy as needed to get a task done without wasting energy. In order to run your best and fastest, you need to keep stimulating the muscles involved in running with a good warmup. Your brain and nervous system will recruit more and more muscle groups in order to spread the workload. By recruiting more muscles you can run faster and determine your true abilities.
Suggested Run Warmup: 5-10 minutes brisk walking with muscle activation drills. 5-10 minutes easy jogging, with three twenty-second strides thrown in, 2-3 minute recovery between strides. Be sure to take a minimum three-minute recovery before beginning the test, so your muscles can recruit the energy systems needed.
- Begin 20-minute effort at the maximum sustainable effort.
- If needed start slightly below what you think you can sustain, but continue increasing effort without going harder than you can sustain for the duration of the test. You should finish knowing you gave it everything you had.
- Your estimated Lactate Threshold Heart Rate (LTHR) is 95% of your 20-minute average heart rate for the test.
- 15 minutes easy cool down with stretching
Now you can do some simple math to determine heart rate training zones, either relative to your LTHR, or as a percentage. These zones are starting points. Each test will have some variation as heart rates can vary from day to day depending on several factors. Taking 95% of your 20-minute average HR is just an estimate for your “true” threshold heart rate which could be determined with a 60-minute time trial.
As long as you maintain the same conditions from test to test, the 20-minute test is excellent for maintaining your current heart rate zones and measuring progress from test to test throughout the season. Record in your training logs your 20-minute heart rate average, the total distance covered for the test and the average speed of the test.
The heart rate is used to determine training zones, and the average speed and distance are used to measure progress from test to test.
| Zone | % LTHR | Easy Math |
| Level 1 (Recovery Zone) | 0-68% | < LTHR – 35 beats |
| Level 2 (Endurance) | 69-83% | 25 – 35 beats below LTHR |
| Level 3 (Tempo) | 84-94% | 15 beats below LTHR up to LTHR |
| Level 4 (Threshold) | 95-105% | Tested LTHR from time trial |
| Level 5 (VO2) | >106% | 5-10 beats above LTHR |
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Additional Run Testing Resources
5K Running Field Test
A 5k race or field test is a fantastic way to regularly check your current fitness, training paces and heart rate zones. After you test, be sure to use our Running Pace Training Zone Calculator to determine your training zones.
Steel City’s Running Pace Training Zone Calculator
Our own running pace training zone calculator uses well established physiologic principals and a logarithmic regression that accounts for human fatigue rates. What’s that mean? It’s among the most accurate training pace estimators available on the internet.
McMillan Training Zone Calculator
While we enjoy using our own calculator for customized training plans, in a quick pinch the McMillan Training Zone Calculator is one of the best out there. Like ours, Greg McMillan’s calculator is based on human physiology, and also accounts for variations in muscle fiber type (sprinter vs endurance). Have fun with this one!
Running World Pace Calculator
Running World gets our vote for one of the top calculators because they use the same reference material that we do! it’s laid out so that you can enter 2 different previous race times to get your estimated goal race pace. This one is Steel City Approved!
References
Disclosure: As an Amazon Associate I earn from qualifying purchases.
The Triathlete’s Training Bible, Joe Friel
Training and Racing with a Power Meter, Hunter Allen & Andy Coggan
Dr. Phil Skiba, personal communication
Dr. Skiba’s great book:
