In honor of February being Heart Health Month, let’s look at the heart and how heart rate training zones can impact exercise.
What is a heart rate training zone?
Heart rate training zones are a percentage of your maximum heart rate. We should not be exercising at, or near, maximum heart rates for very long or very often. Heart rate zones help you to gauge your intensity of workout and help you train efficiently while still achieving a challenging level of fitness. As you go through your workout, any time you increase speed, elevation, workload, etc., you are increasing the intensity and demand on the heart. Using these measurements of heart rate during exercise can help to monitor how hard you are training and help you to adjust your level of workout as needed.
The five training zones
Zone 1 is considered the target range for warm-up and recovery work and should be about 50-60% of your heart rate (HR) max. Zone 2 is considered the target range for aerobic and base fitness work and should be about 60-70% of your HRmax. Zone 3 is the range for aerobic endurance work and should put you at about 70-80% of your HRmax. Zone 4 is for anaerobic capacity, the limit of energy your body can produce using anaerobic means, and should be about 80-90% of your HRmax. Zone 5 is the target zone for short burst speed training and should be about 90-100% of your HRmax.
What does this all mean?
You can train in different zones for different benefits. Lower intensity zones like 1 and 2 will have a higher percentage of calories burned coming from fat, which can be helpful in some weight loss journeys. You may burn less calories overall in the lower intensity workouts; when you compare 20 minutes in zone 2 versus 20 minutes in zone 4, you burn less calories in zone 2 in that time, but we can often sustain zone 2 for a longer period of time. Higher zones like 4 and 5 help to develop efficiency, burn the most calories overall when comparing short bursts of time, but are zones we can sustain for the shortest amount of time.
Zones let you know how hard you are working and what energy sources are fueling your workout. You do not have to be only in one zone for the whole workout, and cycling through zones might benefit your workout. Sometimes you have less time and want to work harder, sometimes you have more time and want to work at a lighter intensity for longer. Using your heart rate is meant to be a guide to help you reach those goals while listening to your body.
How to calculate your heart rate training zone
To find your target heart rate and estimate which zone you are in, you want to first know your maximal heart rate. The simplest estimate of maximum heart rate is 220 beats per minute (bpm) – your current age. Take that number and multiply by the percentage of your target heart rate zone. See the table below for good examples of calculating your average maximum heartrate. For an example, a 40-year-old male would have an estimated maximum heart rate of 180 bpm (calculated as 220 bpm – 40 years of age = 180 bpm maximum), and to be exercising at 65% (which is a zone 2 range), his rate should be about 117 bpm (calculated at 180 * .65 = 117).
| Age | Target HR Zone 50-85% | Average Maximum Heart Rate, 100% |
| 20 years | 100-170 bpm | 200 bpm |
| 30 years | 95-162 bpm | 190 bpm |
| 35 years | 93-157 bpm | 185 bpm |
| 40 years | 90-153 bpm | 180 bpm |
| 45 years | 88-149 bpm | 175 bpm |
| 50 years | 85-145 bpm | 170 bpm |
| 55 years | 83-140 bpm | 165 bpm |
| 60 years | 80-136 bpm | 160 bpm |
| 65 years | 78-132 bpm | 155 bpm |
| 70 years | 75-128 bpm | 150 bpm |
Why should I target different heart rate training zones?
As a general guide, it is good to mix up your heart rate training zones to have more generalized or specific in your workouts to achieve different fitness benefits. If you find your heart rate going too high outside of your intended zone, it may mean you need to pull back a little, or if your heart rate is below your target, you can give yourself a little push to up the intensity.
Where should I start?
When starting to exercise, it is better to start at lower zones, both for a single workout session or during a warm-up. When starting an exercise program in general, start low and build slow as you become comfortable. Remember that heart rate monitoring during exercise is not a requirement and may not work for everyone, it is a helpful tool to help guide you. There are times this might be valuable information and influence your training, while for others it might not necessary. What matters more is being active and aiming for more movement and exercise, and it is up to you how you do that.
Kimberly Burke is a lecturer in the Department of Health and Exercise Science and the director of their Adult Fitness Program at Colorado State University. Adult Fitness offers exercise opportunities for employees of CSU as well as community members, while providing hands-on learning experiences for health promotion students. To learn more, see the Adult Fitness Program website
Sources:
- (2022, August 24). Exercise heart rate zones explained. Cleveland Clinic. Retrieved February 3, 2023, from https://health.clevelandclinic.org/exercise-heart-rate-zones-explained/
- Table: American Heart Association
- Target heart rates chart. www.heart.org. (2022, July 19). Retrieved February 3, 2023, from https://www.heart.org/en/healthy-living/fitness/fitness-basics/target-heart-rates
