With the fitness boom that has taken place over the last few years; wearable technology has flooded the market. Every second person is now walking around with a FitBit or a Garmin heart rate monitor. But what exactly is that number on your watch, and how do you know what your heart rate should be?
Your heart rate is simply how fast your heart is beating. This number depends on many things: your genetics, fitness level, stress levels, and what you are doing at that moment in time. When you’re sitting still, your heart rate will be lower than when you are running.
Heart rate is measured in beats per minute (or BPM). The average, healthy resting heart rate (how fast your heart is beating when you’re standing still) is between 60 and 100bpm. Athletes, however, can have much lower heart rates. It is generally accepted that the fitter you are, the lower your resting heart rate, although genetics do also play a role.
Training according to heart rate zones means determining what your heart rate is when you are exercising at different levels. You can then adjust the intensity of your training according to your goals. It is fairly simple to calculate, although the science behind it is very complex.
Below I have outlined the different heart rate zones, as well as the average bpm for each. Please note that this is not entirely accurate. A more accurate method is given in Calculating your Heart Rate Zones (see below):
- 60-70% of your heart rate reserve: slow, recovery exercise. 139-152bpm
- 70-80% of your heart rate reserve: aerobic zone. 152-166bpm
- 80-90% of your heart rate reserve: anaerobic zone. 166-179bpm.
- 90-100% of your heart rate reserve: VO2 max or “red line zone”. 179-192bpm
(Your heart rate reserve is, simply put, the number of heart beats you have reserved for exercise.)
Calculating your heart rate zones
Although it may seem complicated, calculating your training zones is fairly simple if you don’t delve into the science of it and follow a formula.
There are average heart rates given for each zone, but I prefer using a formula which takes into account both your age and your resting heart rate. Below are the steps to follow:
- Measure your resting heart rate. When you wake up in the morning find your pulse and count how many times your heart beats in one minute.
- Calculate your maximum heart rate. The simplest way to do this is to subtract your age from 220.
- Calculate your heart rate reserve. Subtracting your resting heart rate from your maximum heart rate will give you your heart rate reserve.
- Calculate your heart rate zones. Take your heart rate reserve and work out the percentage you wish to know. Then add that to your resting heart rate. This will give you the beats per minute for the heart rate percentage you have specified.
Confused? Here’s an example
- Resting heart rate of 67bpm
- Age is 25. 220-25 = 195. Maximum heart rate is 195 bpm.
- 195bpm-67bpm= 128bpm. Heart rate reserve is 128bpm
- I want to work out what my 60% zone is. 60% of heart rate reserve (128) is 76,8. Add resting heart rate (67bpm) to 76,8 and you get 143,8bpm. This means that if I want to train at 60%, my heart rate should be around 144bpm.
Which zone should I be aiming for?
There are many schools of thought regarding this, as discussed in my blog post titled HIIT or steady state training?- The Great Debate. – https://www.body-dynamics.co.za/2017/06/22/hiit-or-steady-state-training-the-great-debate/
Which heart rate zone you train in depends on what your goal is for your training session. If you want an easy or recovery run, you would train at 60-70% of your heart rate. This could mean a slow run for an extended period of time. If you want to improve your aerobic fitness you would aim for 70-80%. This would be a slightly shorter run, but still not interval training. If you want to improve your explosive fitness, anaerobic fitness, and do interval or HIIT training; you would aim for 80-90%. Aiming any higher than that is unadvisable as it can be dangerous and damaging to your heart.
Note: there has long been the belief that you burn more fat at a lower heart rate. While this may be true in the sense that for steady state, extended periods of training your body’s preferred form of fuel is fat; it is now believed that high intensity training may be more beneficial in terms of total calories burned and increased metabolic rate following training sessions.
Please note that although heart rate zones can be useful in determining your workout intensity level, they are not the be all and end all. How you feel during a workout is also a good indicator of how hard you are training, and you should never ignore your body.
I hope you’ve found this helpful! Keep an eye on our blog for a blog post on how to get the most out of your fitness watch. Happy training!
by Chanel Serfontein