My empirical evidence of Heart Rate does not match that expounded by Internet Experts and Fitness Influencers. To try to figure out what was going on I bought a HR Chest Strap and am using this to take all my Heart Rate measurements. The HR Chest Strap proved to be more accurate than the Watch HR monitor.
Here is a summary of my findings about my heart rate:
Garmin defines the Heart Rate Zones as:
After some testing I reckon my Max Heart Rate is around 185:
When I compare a run and a walk in terms of Heart Rate and Zones neither seem right.
The results look like this.
With my Max HR set to 185, I am finding a very brisk walk hardly puts me in Zone 2, sometimes I do not even get out of Zone 1. But if I start running (not sprinting) my Heart Rate skyrockets and I can end up in Zone 5 (maximum) for well over 10 minutes on a short run and longer on a longer run. If my Heart Rate was low for a fast walk at 6.7kmph, I would not expect it to be stuck in Zone 5 for a slowish run at 10.20kmph. But thats exactly whats happening:
If I adjust my Max HR to 190, I still spend too long in Zone 5:
If I adjust my Max HR to 195, it pushes the 6.7kmph walk into Zone 1 which does not seem right:
Talk test, I can hold a conversation until about 140ish, so if I use 140 as my upper limit for Zone 2 thish gives a Max HR of 200. This makes the run spot on in terms of perceived effort, but it pushes the 6.7kmph walk into Zone 1. This means a 6.7kmph brisk walk is in the same zone as a normal walk. And a slow walk is in Zone 0 which is the same Zone as sitting on the couch eating doughnuts!
My conclusion based on empirical evidence is that I reckon heart rate zones are not linear, and should not be based on simple percentges. Researching outside of the usual fitness group-think web sites parroting the same information I found that heart rate with regard to actual and perceived effort is substrantially effected by the following:
These websites have good articles on Cardiac Drift
Upward rise of your heart rate during exercise over a long, continuous workout, even though the intensity of exercise has remained constant. This is particularly noticable when its hot. What is happening is that running or exercising causes an increase in core temperature and dehydration, a loss of body fluids through sweat. An elevation in heart rate is associated with this increase in core body temperature, partially due to the fact that the body increases circulation to the skin in order to promote evaporative cooling.
If you’re measuring heart rate during exercise keep in mind the phenomenon of cardiac drift and that your heart rate may be up to 15% higher than you’re expecting for a given work rate. This has a knock-on effect if the aim of a specific training session is to be exercising in a specific heart rate zone or window.
Deconditioned athletes typically have a higher resting heart rate, and their heart rate climbs faster and more intensely than that of a condition athlete. This Heart Rate surging often does not correspond to the deconditioned athlete’s perceived exersion.
They feel they are performing a medium-intensity activity whereas their heart rate data would suggest they are going at high intensity. The more conditioned the athlete, the closer the correlation between HR and RPE typically is.
This great article sums it up!