The image above is a guideline on generic heart rate zones during exercise, for people of certain ages. These days everyone who has a fitness tracking watch around their wrists with the functionality of taking your heart rate will be able to use a chart like this. A few years back, I had a Polar watch with a body strap that fitted just underneath my chest area and the heart rate monitor had to be on the side of your heart. According to that, I got my calculated calories burned, heart rate zones, and duration of the exercise session. This all was calculated with the information I have programmed into the watch, for example, my weight, height, max heart rate zone, and age.
Today’s fitness trackers use different kinds of lights (1), which penetrates into your body to calculate your heart rate. Some are more efficient than others. The one that I have used a few years back is more accurate (2) that the ones you wear around your wrists but I have to admit, I don’t want to wear a chest strapped heart rate monitor the whole day. It’s kind of uncomfortable and after an exercise session, that strap is wet.

The above image shows you my workout session this morning. It was a walk and if you compare it to the generic heart rate table, you will see that I have had a low-intensity session. But if you have had walked with me, you would have seen how out of breath I was on some parts of the walk. For me, how it felt, it was a hard enough session. So if this table shows that it was a low-intensity session but I felt it was hard enough due to my heavy breathing, why don’t the results correspond to what I feel?
Calculating max heart rate
Calculating your max heart is a must if you want accurate readings according to the app installed on your phone. The generic way is to take your 220 – (your age) = max heart rate. But again, this is generic and not correct at all. When I had a personal trainer a few years back, he helped me in calculating my max heart rate by making me run on a treadmill.
Method:
Make sure you haven’t trained hard before doing this test for a few days at least. Also, do not do the following test if you have been sick 2 weeks prior or are currently coming down with something. This test places stress on your heart, so if you have a heart condition, please do not do this test without medical supervision. (3)
You can do the following test on your own with the help of someone. You can do the test either on a treadmill or up a hill.
- Warm-up for 15 minutes on a flat surface. Build up to your usual training pace.
- Choose a hill setting on the treadmill. Run the hill setting (for at least 2 minutes), building to as hard a pace as you estimate you could hold for 20 minutes. (You don’t have to keep running for 20 minutes, you just need to build up to a pace that you could hold for at least 20 minutes.) Return to flat setting on the treadmill after 2 minutes.
- Run the hill setting again but this time at a faster pace. Get your heart going as hard as you can, building up to a pace you estimate you would be able to hold for 3km. Observe your highest heart rate on the display. Your max heart rate is +/- 10 beats higher than the now-noted value.
- Run the flat setting, allowing your heart rate to drop 30–40 beats per minute from where it was.
- Run the hill setting once again at a pace that you can only hold for 1 minute. Observe your highest heart rate. This brings you close to your maximum heart rate. You can use this value as your max HR to set your heart rate zones.
- Make sure you cool down for a minimum of 10 minutes.
With the above test, which I haven’t done and thus the reading on the app this morning said “low-intensity”, you will get a more accurate reading if you have done the above test and programmed the app accordingly (with the correct max heart rate according to your fitness level). This test should be done every 3 months to ensure you have the correct max heart rate according to your fitness level in that particular time of your life. Please do not compare yourself to my stats. There are different things that influence fitness levels. Things from medications you take, burn out and stress, just to name a FEW.
Enjoy the fitness tracker you have along with your workouts. it’s a great way to keep motivated and see your progress.
Resources:
1 – https://www.wareable.com/fitbit/fitbit-red-light-optical-sensor-technology-2034
2 – https://breakingmuscle.com/fitness/chest-strap-vs-wristband-heart-rate-monitors
3 – https://www.polar.com/blog/calculate-maximum-heart-rate-running/