Lactate Threshold Heart Rate Zone Calculator

This is your average heart rate during the last 20 minutes of a 30-minute maximal effort time trial.

Your Personalized Training Zones

Zone	Description	Heart Rate Range (BPM)

Understanding Lactate Threshold Heart Rate (LTHR)

Lactate Threshold Heart Rate (LTHR) is one of the most effective metrics for endurance athletes to set their training intensity. Unlike calculations based on age (like 220 minus age), which are often inaccurate by up to 20 beats per minute, LTHR is based on your unique physiology and current fitness level.

What is Lactate Threshold?

Your lactate threshold is the point during exercise where lactate begins to accumulate in your blood faster than your body can remove it. For most athletes, this represents the maximum intensity they can sustain for approximately 60 minutes. Training based on LTHR zones allows you to target specific metabolic systems, whether you're building aerobic base or increasing anaerobic capacity.

How to Find Your LTHR: The 30-Minute Test

The most common way to find your LTHR, popularized by coach Joe Friel, is a 30-minute time trial performed alone (not in a race or group):

1. Warm-up: 15 minutes of easy effort.
2. The Test: Run or cycle for 30 minutes at your maximal sustainable effort. It should be a steady, hard pace—not a sprint that causes you to blow up halfway through.
3. Record: 10 minutes into the test, hit the "lap" button on your heart rate monitor.
4. The Result: Your average heart rate for the final 20 minutes of the test is your estimated LTHR.

The 7 Training Zones Explained

This calculator uses the Friel Method to divide your training into specific zones:

• Zone 1 (Recovery): Used for active recovery days. The intensity is very light.
• Zone 2 (Aerobic): Your "base" building zone. This is where you should spend most of your long-distance training time.
• Zone 3 (Tempo): Moderate intensity. Improves ability to hold a faster pace for longer.
• Zone 4 (Sub-Threshold): Just below your LTHR. Crucial for improving performance in races lasting 30-60 minutes.
• Zone 5a (Super-Threshold): Just above your LTHR. Focuses on increasing your lactate threshold point.
• Zone 5b (Aerobic Capacity): VO2 Max training. Very high intensity intervals.
• Zone 5c (Anaerobic Capacity): Short, explosive sprints at maximum effort.

Example Calculation

If an athlete has a tested LTHR of 170 BPM, their zones would be calculated as follows:

Zone 2 (85-89%)	145 – 151 BPM
Zone 4 (95-99%)	162 – 168 BPM
Zone 5a (100-102%)	170 – 173 BPM