HR Zones 101

How do you know if you’re training at the correct intensity?

Using Heart rate zones (HR zones) is one effective way to monitor how hard you’re training or competing. There are five HR zones based on the intensity of physical activity relating to your estimated maximum heart rate (HR Max).

HR zones are closely linked to your aerobic and anaerobic thresholds. Understanding this can really help when considering HR zones for planned physical activity, especially your HR zones for performance running or effective weight loss.

Simply put, HR zones can be defined as percentages of your estimated HR Max.

What are the HR zones?

There are five different heart rate zones (1–5) and your training plan can (and should) include workouts in all five zones. This HR zone chart shows the level of intensity and percentage of estimated HR Max used in each one.

Heart Rate Zone One (50-60% of HR Max)

This is the very light intensity zone. Training at this intensity will boost your recovery and get you ready to train in the higher heart rate zones.

To train at this intensity, pick a form of exercise that allows you to easily control your heart rate, such as walking or cycling.

Heart Rate Zone Two (60-70% of HR Max)

Exercising in heart rate zone 2 feels light and you should be able to go on for a long time at this intensity.

This is the zone that improves your general endurance and overall performance at higher intensities: your body will get better at oxidizing, or burning fat and your muscular fitness will increase along with your capillary density.

Training in heart rate zone 2 is an essential part of every exercise program. More and more data suggest that this where the majority of your cardio activity should be focused at for optimal health and performance. So keep at it and you’ll reap the benefits in the long run.

Examples include walking, hiking, cycling and swimming.

Heart Rate Zone Three (70-80% of HR Max)

Working out in heart rate zone 3 is especially effective for improving the efficiency of blood circulation in the heart and skeletal muscles. This is the zone that lactic acid usually starts building up in your bloodstream, causing muscular fatigue.

Training in this HR zone will make moderate efforts easier and improve your efficiency.

Heart Rate Zone Four (80-90% of HR Max)

Heart rate zone 4 is where the going gets tough. You’ll be breathing hard and working around the transition point of aerobic and anaerobic (without oxygen) activity.

If you train at this intensity, you’ll improve your speed endurance. Your body will get better at using carbohydrates for energy and you’ll be able to withstand higher levels of lactic acid in your blood for longer.

Heart Rate Zone Five (90-100% of HR Max)

Heart rate zone 5 is your maximal effort. Your heart and your blood and respiratory system will be working at their maximal capacity. Lactic acid will build up in your blood and after a few minutes you won’t be able to continue at this intensity.

If you’re just starting out or have only been training for some time, you probably won’t have to train at this intensity. If you’re a professional athlete, look into incorporating interval training into your training plan for peak performance.

Examples are very short maximal efforts such as 40-100m sprints.

How to calculate HR zones

To calculate your individual HR zones firstly you will require to know your maximum heart rate. A simple way to calculate an estimate is to use the following formula:

• 220 – age = HR Max

Another, more accurate formula to calculate estimated HR Max is:

• 206.9 – (0.67 x age) = HR Max

From here you are just calculating work rate percentages based off your HR Max. This can be done by multiplying your estimated HR Max by the minimum and maximum percentages for the required training zones.

For example, if a 35-year-old athlete was looking to conduct some zone two work the equations would like this:

• 220 – 35 = 185 bpm
  • 185 x 0.60 = 111 bpm
  • 185 x 0.70 = 130 bpm

And with the second formula:

• 206.9 – (0.67 x 35) = 183.5 bpm
  • 183.5 x 0.60 = 110 bpm
  • 183.5 x 0.70 = 128 bpm

Now that you have calculated your HR for each of the training zones, you will have more of an understanding of how hard you’re actually working during a session.

If you want to really capitalize on the benefits, then sit down with a coach and work together to develop a training plan to improve your overall fitness, and making you faster, fitter and stronger for longer. You will reap the rewards in the long run.