Heart Rate Zones

Heart Rate Zones: What are yours?

With the rise in popularity of biometric tracking devices like fitbits, apple watches, garmins, etc. heart rate monitoring has become an increasingly popular method of tracking fitness and workout intensity. Using these devices allows instant feedback with a simple glance at your wrist and also data collection for long term trend tracking. When you look back at that data, the heart rate tracking is often split into zones, but what do they mean? 

Heart rate zones represent a percentage of your age predicted max heart rate. Age predicted max heart rate is calculated as 220-your age (e.g. if you’re 40, 220-40 = 180 beats per minute (BPM)). This is your best estimate of the max heart rate your heart can beat. Each zone is calculated as a percentage of your predicted maximum: 

• Zone 1: Very Light (50-60% of Max HR) 

• Zone 2: Light (60-70% of Max HR) 

• Zone 3: Moderate (70-80% of Max HR) 

• Zone 4: Hard (80-90% of Max HR) 

• Zone 5: Maximum (90-100% of Max HR)

There are limitations to this simple calculation. Many people will have a max heart rate that is either significantly lower or higher than their age predicted maximum. This means that the zone automatically calculated by your watch or fitbit won’t necessarily reflect your personal capacity or how hard or easy you perceive you are exercising. If you still want to use heart rate zones as a way to structure your training, you may need to calculate your target ranges manually based on your own measured max heart rate. 

For example: if you’re 40 but the highest heart rate you have noticed during your ‘self-described’ maximum effort is 170BPM, then your max heart rate may be 10 BPM lower than your age predicted max of 180BPM. This means that for you, 

• Zone 1 will be <102BPM instead of < 108BPM

• Zone 2 103-119BPM, not 109-126BPM

• Zone 3 120-136BPM, not 127-144BPM

• Zone 4 137-153BPM, not 145-162 BPM

• Zone 5 is >154BPM instead of >163BPM

In order to use your watch or fitbit to train in these more personalized zone values, you will need to manually update these targets in the settings. With the current popularity of zone 2 cardio, understanding how to personalize that zone target is essential if this type of training interests you. Check out next months article to learn more.

An alternative to having to focus so much on a tracking device is to use ratings of perceived exertion (RPE) to monitor your training state. This scale is easy to use and there is a lot of research to support how well it works. Essentially it’s a 1-10 rating of how much effort you are putting in to complete an activity. 

1 - no activity, laying on the couch

2-3 light activity, you can easily carry on a conversation (Zone 1)

4-5 moderate activity, you can talk but you might have to pant occasionally (Zone 2)

6-7 moderate to vigorous activity, talking is hard and comes out in bursts as you breath (Zone 3)

8-9 vigorous activity, talking is almost impossible (Zone 4)

10 max activity, you have nothing left in the tank (Zone 5)

And the final and most important target? Have fun out there being active!