A heart rate of 150 beats per minute can reflect two very different levels of effort. For a trained cyclist, it may be sustainable for a long time; for a weekend cyclist, it could already be difficult to maintain. The reading is identical, but the body’s response is not.

Training zones are used to set the intensity of a workout and ensure that it matches the purpose of the session. They are often calculated using standard percentages of maximum heart rate. This can be a useful guide, but it does not reflect how close each person is to their physiological thresholds. As a result, a workout intended to be low-intensity may demand more effort than expected.

As exercise intensity increases, the body changes the way it sustains the effort. Metabolic and ventilatory thresholds help identify these transitions, which do not occur at the same percentage of maximum heart rate in every individual. A targeted assessment therefore provides more reliable information than a standard formula applied to everyone.

HPM uses data collected during performance testing to establish individual reference points. Power measurements and analysis of the power-duration curve show how much power an athlete can produce, in watts, over efforts of different lengths. These findings help define training zones that better reflect the athlete’s capabilities and guide the next phase of training.

Those reference points, however, do not necessarily remain valid throughout the season. Fitness may improve or change after a period of inactivity, while the same training session may produce different responses over time. Monitoring helps establish whether the selected intensities are still appropriate and, when necessary, adjust the training programme.

The value of a training zone lies in knowing which stimulus is being prescribed and having concrete evidence of how the athlete is responding to it.