Training Intensity

How do you know what intensity you should be training at? At different training intensities your body will receive different training effects. What level is right for what?

There are a number of ways you can measure training intensity from very precise methods such as using power for cycling, pace training for running, heart rate (HR) training for either, or a subjective method such as utilising the Borg Scale.

Focusing on the intricacies of the power, pace or HR training is beyond the scope of this article other than providing a comparison of the intensities across the board.

If we dial it down there are effectively five broad intensities. Yes, I know some of the methodology I use has more ‘zones’ in it such as the Pace Zone Index which goes from Pace Zone (PZ) 1 right through to 10, but we only really use PZ2, PZ3, PZ4, PZ6 and PZ8; i.e. five of the zones.

If you work with me on a coaching programme with HR or power based programme you will be familiar with five zones:

  • Recovery
  • Endurance
  • Tempo
  • Threshold and
  • VO2 Max

For the purposes of this lets rename them:

  • Level I (Recovery)
  • level II (Endurance)
  • Level III (Tempo)
  • Level IV (Threshold) and
  • Level V (VO2 Max)

When you increase your intensity of exercise you will move from Level I through to Level V. You can even go past Level V if you push yourself hard enough, but I only use that intensity in very select and specialist situations. If you are running, as you move from Level I to Level V you will end up running faster and faster and your HR will increase up to close to your maximum. If you are cycling you will be generating more and more power as you go up to and past Level V. Conversely your HR will also increase as your power level increases.

If you don’t have a HR monitor, Power Meter or GPS device to tell you what is happening, be assured these things are still happening even though you will be unable to  quantify it with numbers/data. You will notice a few things happening, especially up towards Level V as you start to get out of breath.

Level I

At this level the pace is nice and relaxed, power generated is minimal and the HR is relatively low but above resting levels. You will be able to maintain a conversation with a training partner without any issues at all. This intensity will assist moving blood and waste products (lactic acid etc…) to the liver and kidney to be filtered out of the body. Not much training effect occurs at this level.

It is the equivalent to below Borg 2-3, PZ2, and the Recovery HR or Power Zone.

Level II

Once again the pace is nice and relaxed although a little more effort is applied compared with Level I. At this effort level, you will create some beneficial biochemical and anatomical changes to the body that enhances your physiology. You will increase the number of mitochondria in each active muscle fibre as well as improving the efficiency of the heart and lungs. This very beneficial if you are an endurance athlete and will maximise recovery if you are a strength or anaerobic athlete.

It is the equivalent to Borg 2-3, PZ3, and the Endurance HR or Power Zone.Fast Cyclist

Level III

Stepping things up a little more, you will not be out of breath but if you were trying to talk to a training partner you will need to catch your breath between sentences of your conversation. At this level you will increase the capacity for the body to store glycogen in the muscles and further enhance the efficiency of the heart and lungs.

It is the equivalent to below Borg 4-5, PZ4, and the Tempo HR or Power Zone.

Level IV

As we increase things we start to go anaerobic and can’t maintain this intensity too long but can comfortably do so for at least 20 minutes or longer. At this level our conversation is short and based around short sentences of a few words at a time. We will be increasing our ability to produce and clear lactic acid from the system increasing our lactate threshold.

It is the equivalent to Borg 6-7, PZ6, and the Threshold HR or Power Zone.

Level V

At the top level discussed here, it the highest level we can maintain for a few minutes at a time where we increase our maximal uptake of oxygen, increasing the size of the heart and it’s cardiac output. At this level you will be sucking in oxygen and only able to grunt and groan.

It is the equivalent to greater than Borg 8, PZ8, and the VO2 Max HR or Power Zone.

Here is a summary chart for you to use as a comparison. Highest priority should go to the left hand side metrics (power and pace, over HR or subjective).

Level Cycling Power Running Pace Zone HR Zone Borg Scale
I Recovery Power Zone PZ2 Recovery HR Zone <2
II Endurance Power Zone PZ3 Endurance HR Zone 2-3
III Tempo Power Zone PZ4 Tempo HR Zone 4-5
IV Threshold Power Zone PZ6 Threshold HR Zone 6-8
V VO2 Max Power Zone PZ8/10 VO2 Max HR Zone 9-10

Each of us is capable of exercising at any of these intensities. It will create an equal amount of discomfort for us all. The difference is how fast we are travelling at these various levels. A fitter, faster athlete will be going a lot faster or generating more power than an unfit or beginner athlete at Level II. If they were running side by side at the same pace, we might find that the fitter athlete is at Level I or II whilst at the same time and whilst running the same pace the beginner is at Level V!!! The fitter athlete will be able to maintain that pace for hours whilst the beginner will only be able to hold Level V for a few minutes. If we made the fit athlete run at Level V they too will only be able to hold it for a few minutes.

Coach Ray is the Head Coach & Director of Qwik Kiwi – Endurance Sports Consultant.

Coach Ray specialises in assisting first timers and recreational athletes to achieve their sporting goals. He can be contacted at  and 021 348 729. Make sure you sign up to his monthly informative newsletter.

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225 Replies to “Training Intensity”

  1. This is a gooden’ Ray. Is this all your own knowledge? (without that sounding insulting)

    1. Unfortunately I can’t claim to have developed Dr Jack Daniel’s Pace Zone Index, or Gunnar Borg’s ‘Borg Scale’ or invented measuring training intensity with Heart Rate or Power. However putting it all together in a concise formate and simplifying it into these five levels is mine and how I describe intensity to my athletes.

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