Although it is common practice to use a system of ‘Zones’ to distinguish between different training intensities, in reality, the human energy systems never work in isolation. They harmonise at every level, producing a spectrum of intensities that blend seamlessly into one another. Every intensity supports, and is supported by, the intensity alongside. Providing anaerobic support for the level below, and aerobic support for the level above.

There is no magic intensity to solely focus on, and there are no ‘grey’ zones to avoid completely. To maximise your potential as an athlete, it is essential that you train every intensity to an appropriate level. Your race power/pace will always be supported by the intensities above and below it, which in turn will be supported by the next intensities in the chain, which in turn will be supported by the next, and so on. From pure neuromuscular power/speed to very easy endurance, for optimal performance - no intensity can be neglected.

Although we encourage you not to think of training intensities as distinct ‘Zones’, for the practical purpose of prescribing workouts, at Tri-High Performance, we also use a system of categorisation. You will find our Training ‘Levels’ in the links below.


To calculate your own specific Training Levels that are used within the THP system, and determine predicted race performances over various distances - make use of out Training Level Calculator