Calculating Your Target Heart Zone

Here’s how the POLAR system recommends figuring your target heart rate using your age and current fitness level*

Polar Age and fitness level based formula for identifying Target Heart Rate 1

This formula uses your age and fitness level to determine your target zones. It is a more personalized number and recommended for people who are experienced exercisers.

First, you must take your heart rate for three mornings in a row before getting up from bed. Once you have those numbers you can calculate their average by summing them and then dividing the sum by 3.

(Morning 1 + Morning 2 + Morning 3)/ 3 = Morning Resting Heart Rate (MRHR)

This is the single best indicator of your state of fitness. Once you have this number established as a baseline, you can use it to understand more about yourself than you can imagine. Take it again every once in a while, at least once every two weeks.

As your fitness improves, you will most likely see that number going down. If you see an elevated number, it could mean one or more of the following:

  •     You did not recover from a hard workout the day before
  •     You need more rest
  •     Your body has begun fighting off an oncoming illness

Your estimated maximum heart rate is 220 minus your age. In order to get your target heart rate zones you need to do the following calculations:


*Taken from Polar: *

*Taken from Polar: *


Jane is 30 years old and her morning resting heart rate is 70. Her estimated maximum heart rate is 220-30=190.

  • Zone 1 lower limit: (190 - 70) * 0.6 + 70 = 142
  • Zone 1 upper limit: (190 - 70) * 0.7 + 70 = 154
  • Her 60-70% Target Zone would be 142-154

Polar Sport Zones

Polar sport zones offer a new level of effectiveness in heart rate-based training. Training is divided into five sport zones based on percentages of your maximum heart rate. With sport zones, you can easily select and monitor training intensities and follow Polar’s sport zones-based training programs.


Intensity % of HRmax, bpm: 90–100%, 171–190 bpm
Example durations: less than 5 minutes
Training benefit: Benefits: Maximal or near maximal effort for breathing and muscles.
Feels like: Very exhausting for breathing and muscles.
Recommended for: Very experienced and fit athletes. Short intervals only, usually final preparation for short events.

Training in Zones 4 and 5

If your goal is to compete at top potential, you will have to train in heart rate zones 4 and 5. In these zones, you exercise anaerobically, in intervals of up to 10 minutes. The shorter the interval, the higher the intensity. Sufficient recovery between intervals is very important. The training pattern in zones 4 and 5 is designed to produce peak performance.

The Polar target heart rate zones can be personalized by using a laboratory measured HRmax value, or by taking a field test to measure the value yourself. When training in a target heart rate zone, try to make use of the entire zone. The mid-zone is a good target, but keeping your heart rate at that exact level all the time is not necessary. Heart rate gradually adjusts to training intensity. For instance, when crossing from heart rate target zone 1 to 3, the circulatory system and heart rate will adjust in 3-5 minutes.



Intensity % of HRmax, bpm: 80–90%, 152–172 bpm
Example durations: 2 – 10 minutes
Training benefit: Benefits: Increased ability to sustain high speed endurance.
Feels like: Causes muscular fatigue and heavy breathing.
Recommended for:Experienced athletes for
year-round training, and for various durations. Becomes more important during pre competition season.



Intensity % of HRmax, bpm: 70–80%, 133–152 bpm
Example durations: 10 – 40 minutes
Benefits: Enhances general training pace, makes moderate intensity efforts easier and improves efficiency.
Feels like: Steady, controlled, fast breathing.
Recommended for: Athletes training for events, or looking for performance gains.

Training in Zone 3

Aerobic power is enhanced in heart rate zone 3. The training intensity is higher than in sport zones 1 and 2, but still mainly aerobic. Training in sport zone 3 may, for example, consist of intervals followed by recovery. Training in this zone is especially effective for improving the efficiency of blood circulation in the heart and skeletal muscles.



Intensity % of HRmax, bpm: 60–70%, 114-133 bpm
Example durations: 40 – 80 minutes
Training benefit: Benefits: Improves general base fitness, improves recovery and boosts metabolism.
Feels like: Comfortable and easy, low muscle and cardiovascular load.
Recommended for: Everybody for long training sessions during base training periods and for recovery exercises during competition season.

Training in Zone 2

Training in heart rate zone 2 is for endurance training, an essential part of any training program. Training sessions in this zone are easy and aerobic. Long-duration training in this light zone results in effective energy expenditure. Progress will require persistence.



Intensity % of HRmax, bpm: 50–60%, 104–114 bpm
Example durations: 20 – 40 minutes
Training benefit: Benefits: Helps to warm up and cool down and assists recovery.
Feels like: Very easy, little strain.
Recommended for: For recovery and cool-down exercises throughout the training season.

Training in Zone 1

Training in heart rate zone 1 is done at very low intensity. The main training principle is that performance improves when recovering after, and not only during, training. Accelerate the recovery process with very light intensity training.