Indoor Cycling Training Zones

Why use Training Zones?

Training Zones are used because different effort levels have different effects on the body.

Zone Training benefits
1 – Recovery Very easy
2 – Endurance Develops base endurance and aerobic capacity.
Mostly fat burning and improving your ability to use oxygen.
3 – Tempo Develops your Cardio-vascular system (heart, lungs, blood).
Burns fat and improves your ability to use oxygen and expel carbon-dioxide.
Also good for improving muscular power and endurance.
Sweet-Spot Although it’s not often recognised as a specific zone, this is an increasingly popular effort level to train in as it gives good results. It’s consists of upper Tempo and lower Threshold.
4 – Threshold Improves your Lactic Acid system where you work close to your Anaerobic Threshold. In addition to burning fat you’ll use your Glycogen stores (carbohydrates) in your muscles.  This is where Lactic Acid is produced and your leg muscles will start to ache and breathing becomes heavy.
5 – VO2 Max Increases muscle and heart and lung capacity to absorb oxygen.
6 – Anaerobic capacity Improves your ability to tolerate Lactic Acid removing it from the muscles and re-cycling it.

It’s worth noting that the ‘Zones’ fade into one another. In other words the body doesn’t suddenly change from Tempo to Threshold.  In this respect when you’re aiming for a specific Zone try to maintain a heart-rate or power output in the middle of the range.

How to Measure the Training Zones

There are three main ways of defining how hard you are training:

  • Perceived Effort based on feelings and sensations.
  • Heart-Rate
  • Power


Feel is based on your sensations and if you’re just getting into cycling it’s difficult to accurately assess how hard you are working.  Another problem is that it’s not possible to measure how hard you training workout was.


Heart-Rate is reactive which means that it reacts to the amount of effort you are doing.  The problem with using heart-rate for training is that there’s a delay between you changing your effort level and your heart-rate.  This can take a few minutes, so if you’re doing short intervals it’s pretty pointless using higher heart-rate zones.

This is where Power becomes useful.


Power is a combination of how hard you pedal (Force) and how fast you pedal (Cadence).  A power meter will tell you how hard you are working at that moment and gives you more-or-less instant feedback so it’s very useful for doing intervals lasting a few minutes.

The problem is that Power meters are quite an expensive bit of kit but some turbo trainers and indoor bikes have power indicators.  These may not be totally accurate but they’re usually quite consistent and serve the purpose.

Use All Three?

At the end of the day it’s worth using all three – if you can.  Otherwise use heart-rate for Endurance, Tempo and Threshold intervals of over say 3 minutes and feel for the shorter high intensity intervals.

To keep things simple we use six levels of intensity, which is also used by British Cycling as well as the power training gurus Hunter Allen and Andrew Coggan (see Training and racing with a Power Meter by Allen and Coggan).

Zone Intensity Feel Heart-Rate*
1 Recovery Very Easy  Up to 68  <55
2 Endurance Easy 68-83  56-75
3 Tempo Moderate  83-94  76-90
4 Threshold Hard  94 – 105 91-105
5 VO2max Very Hard  105 – 121 106-120
6 Anaerobic Capacity Sprint  — 121-150

%FTHR = Percentage of ‘Functional Threshold Heart-Rate.

%FTP = Percentage of Functional Threshold Power

Functional Threshold is estimated by riding hard for 20 minutes and measuring your average heart-rate and/or power.

The Sweet-Spot Training ‘Zone’

Although it’s not a specific Zone, the Sweet Spot lies at the transition between Tempo and Threshold at 85 to 95% FTP.  This is a good zone to work in if you want to do a 60 to 90 minute high cadence workout with 3 intervals  of 10 to 20 minutes at Sweet Spot.