Heart Rate Zones For Winter

An email from a new athlete got me thinking.

How do I define my heart rate training zones? Why do I define them as such? Why are there so many different zones?
My answer to the athlete, my views, flawed and honest….like my spelling


So the HR zones. First off, setting real HR zones without access to a metabolic system and your blood is going to be ‘smart guesswork’ a the best of times. These zones also change, so using max test values more than 4 months old is pointless in my opinion. I’ve had athletes take 10 beat shifts in their lactate threshold (positive and negative with some over-training incidents)  which would make all the relative zones pointless.

In my experience, both coaching and from the lab work, cyclists have a habit of doing two things. Training to hard or recovering to hard. I base HR and power zones around the 20mins test as an attempted measure of your functional threshold – aka the HR or power output you can sustain for an hour, which roughly equates to your lactate threshold.

Zones are based off the mean HR recorded during a WELL PACED 20mins test – (yours was, so excellent, very little HR variation) – then assumed that this value is more than you’d be able to sustain for an hour, by about 5% – this is pretty much the accepted method that is used for setting an FTP for power. So for you we get:

20mins mean HR
Peak HR
Resting HR
65 (estimated not needed)
Estimated LT
175*0.95-  167 bpm
Rest  LT * 0.6
Rest -  100
LT*0.6 – LT*0.68
100 – 112
LT*0.68 – LT*0.83
112 – 137
LT*0.83 – LT*0.94
137 – 156
LT*0.94 – LT*1.05
156 – 174
LT*1.05 – Max
174 – max
Ish….I use the ish word as I’ll always manually tweak the zones after looking at the data… there are no hard and fast rules if I am honest. Its like the Pirate Code, its more like a set of guidelines…. If you look at your early 4min intervals in that session they all slot in at Z5 whereas your 20mins slots mostly into Z4 – where expected. Above Z5 heart rate means nothing, it is just responding, trying to judge anaerobic efforts on HR is like trying to tell the weather with an internal thermometer, flawed and misguiding.

Finally, during winter months it is better to be somewhat conservative. Train a little less in the red zone, but dipping into it all the time, but aiming to stay consistently within a z3 ride for 3 hours can be quite demanding….that means on descents as well…. so trying to limit the work zones into smaller bands and stay focused will help in later sessions where you can say ‘ok, I have done a Z5 interval, now I have to relax at Z4. I know how that feels’

Each of these earlier zones – Z1 through to Z4 – aim to hit a specific metabolic band. Be it recovery, endurance, threshold riding, or race pace. You need to dip into all of these all the time, but knowing when to dip lower into easier zones is hard for most people as we enjoy training when it is hard….usually this is not hard enough either…its just dead riding. My job is to try and stop that…your job is to make sure you stop that.

FWIW…you’ll be testing again in a few weeks – then we will be adjusting again.

Hopefully this answers your question.


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