Target Heart Rate Zone
The target heart rate zone (THRZ) is a range of heart rate percentages that a person aims for when
exercising. The range is expressed as a percentage of your maximum heart hate (Max HR). Your Max HR is
defined as the maximum amount of times your heart can beat per minute. The American Heart Association
recommends exercising within 50%-85% of your Max HR. While the AHA provides a good guideline to follow,
experienced and suitably fit people can train up to and above 90% of Max HR.
How to find your Target Heart Rate Zone
First determine your Max HR
I will cover both the standard and updated formula for calculating Max HR. Either method is good to use
but the latter is said to be more accurate.
The standard way to calculate Max HR is simply 220 minus your age.
So if you are 30 years old your Max HR is 190.
Solution: 220 - 30 = 190 Max HR
A new and more accurate formula for Max HR was published by the Medicine & Science in Sports & Exercise
journal. The updated formula for Max HR is 206.9 - (0.67 x age). So if you are 30 years of
age your Max HR is 187.
Solution: 206.9 - (0.67 x 30) = 187 Max HR
Then Calculate your THRZ
To find your THRZ simply take 50%-85% of your Max HR.
So if you are 30 years old and your Max HR is 187 your THRZ is 94-159 beats per minute.
.50 X 187 = 94 beats/minute
.85 X 187 = 159 beats/minute
If you want a more personalized and accurate THRZ you can opt to use the Karvonen Formula.
The Five Target
The THRZ can be broken down into 5 separate zones, which all burn fat, improve fitness, and provide health
benefits. The body will burn a higher percentage of fat calories at lower intensities but at higher
intensities you'll burn more total calories. Keep in mind that total calorie expenditure is more crucial than
the percentage breakdown of fat and carb calories. The more total calories burned, the more weight you'll
lose. Yes, it's that simple.
As the zones get higher...
Exercise intensity increases
More calories are burned per minute during exercise
More calories and fat are burned after exercise
More calories and fat are burned around the clock
Your fitness level increases
| Target Zones
|| Percentage of Max HR
|| Exercise Intensity
| Z1 Healthy Heart
|| 50% - 60%
|| Very light to light
| Z2 Temperate
|| 60% - 70%
|| Light to moderate
| Z3 Aerobic
|| 70% - 80%
|| Moderately hard
| Z4 Anaerobic
|| 80% - 90%
| Z5 Red Line
|| 90% - 100%
|| Very hard
Healthy Heart Zone (50% - 60% of Max
The lowest level you can exercise in and still increase your fitness. Suited for beginners or people who have
stopped exercising regularly and lost their conditioning. This zone can be used for just improving your
overall health. It can also be a good recovery zone for people who are over-trained and need to take a
Temperate Zone (60% - 70% of Max
This is the zone where the heart begins to benefit. Training in this zone will begin improve your heart's
ability to pump blood and improve the muscle cells ability to use oxygen. This zone is good for long slow
endurance exercise as the body becomes more efficient at feeding the working muscles more efficiently. In this zone
stored body fat is the primary source of energy utilized hence this zone is referred to as the weight management
Aerobic Zone (70% - 80% of Max
This zone is the most effective for overall cardiovascular fitness. This is the best zone to workout in to
increase your cardio-respiratory capacity, which is the body's ability to transport oxygenated blood to the muscle
cells and carbon dioxide away from the cells. After a while you will be able to cover more distance during workouts
in less time. This zone is also effective for increasing overall muscle strength.
Anaerobic Zone (80% - 90% of Max
HR | 85%-90% = Anaerobic Threshold)
This level is where you cross over from aerobic to anaerobic training which is called the anaerobic
threshold. This is the point where the body cannot effectively remove lactic acid from the working muscles
quickly enough. This zone is mainly for people who want to increase their performance levels. You would
characterize this zone as hard. During exercise in this zone your muscles burn, your breathing is heavy, and
you become fatigued quickly. The benefit of training in this zone is that you can increase your body's
ability to tolerate and deal with lactic acid for a longer period of time as the enzymes in your muscles
responsible for anaerobic metabolism are increased. For sport competitors it is good to become accustomed to
your anaerobic threshold as many fit athletes can compete at or above their anaerobic threshold.
Red Line Zone (90% - 100% of Max HR)
You will only be able to train in this zone for short periods of time. You should not train in this zone
unless you are very fit. In this zone lactic acid builds up very quickly as your muscles are operating with
oxygen debt. The benefit of training in this zone is that you can increase your fast twitch muscle fibers
which increase speed. You will not be able to stay at this intensity level very long so short work intervals
should be used when training in this zone.