Determining rider phenotype and physiological zones


Athletic Phenotype

We measure your aerobic threshold, critical power, W' and maximal neuromuscular power output (in combination with anthropometric factors) to provide a clear picture of your current strengths and weaknesses. Your phenotype is then used to tailor your training programme and maximise development.

Aerobic Threshold

Determination of your aerobic threshold, which marks the lowest power output to elicit an increase in blood lactate concentration from resting levels, is carried out by analysing blood samples, heart rate and perceived exertion during a progressive step test. This intensity represents a point where the metabolic demand can no longer be met through aerobic processes alone, and so the contribution of anaerobic metabolism increases. Although this intensity remains sustainable for a long period of time, different fatigue and adaptive responses can be expected (compared to training below this threshold).


Critical Power

Critical power represents the highest power output you are able to achieve with a stable blood lactate concentration, muscle phosphocreatine and VO2. This is determined using a series of maximal effort time-trials across a variety of durations. This physiological threshold acts as a key metabolic turnpoint, where power output moves from being sustainable to unsustainable.


The series of time-trials used to determine critical power also generates a power-duration curve, from which your capacity to complete work above critical power can be calculated (W'). Furthermore, it is possible to calculate the rate at which W' is recovered once intensity returns below critical power (W'bal). This physiological parameter therefore indicates how much unsustainable work you can carry out, and how long is required for you to recover.

Maximal Neuromuscular Power

Maximal neuromuscular power output is defined as the highest power you can generate through the crank arms of the bike. This is determined through a series of short maximal effort sprints using different gears, with opportunity for complete recovery between efforts.