Power profiling and the power-duration relationship in cycling: a narrative review

Abstract

Emerging trends in technological innovations, data analysis and practical applications have facilitated the measurement of cycling power output in the field, leading to improvements in training prescription, performance testing and race analysis. This review aimed to critically reflect on power profiling strategies in association with the power-duration relationship in cycling, to provide an updated view for applied researchers and practitioners. The authors elaborate on measuring power output followed by an outline of the methodological approaches to power profiling. Moreover, the deriving a power-duration relationship section presents existing concepts of power-duration models alongside exercise intensity domains. Combining laboratory and field testing discusses how traditional laboratory and field testing can be combined to inform and individualize the power profiling approach. Deriving the parameters of power-duration modelling suggests how these measures can be obtained from laboratory and field testing, including criteria for ensuring a high ecological validity (e.g. rider specialization, race demands). It is recommended that field testing should always be conducted in accordance with pre-established guidelines from the existing literature (e.g. set number of prediction trials, inter-trial recovery, road gradient and data analysis). It is also recommended to avoid single effort prediction trials, such as functional threshold power. Power-duration parameter estimates can be derived from the 2 parameter linear or non-linear critical power model: P(t) = W′/t + CP (W′—work capacity above CP; t—time). Structured field testing should be included to obtain an accurate fingerprint of a cyclist’s power profile.

Can Popular High-Intensity Interval Training (HIIT) Models Lead to Impossible Training Sessions?

“…The logical contradictions observed in our simulations occur specifically in cases falling outside the model assumptions for an interval duration of fewer than 3 min. While these limitations are well-acknowledged for the continuous hyperbolic model [ 32 ], we provide mathematical evidence that they propagate to the Skiba intermittent exercise model and affect the prescription and analysis of intermittent efforts in the severe and extreme intensity domain.…”

“…The curves of the graphs in Figure 2 and Figure 3 (especially for Figure 2 A,C and Figure 3 A,C) are not necessarily smooth, which will be discussed in the next section. However, looking at the general trends of each curve, we observe that impossible sessions are characterized by a small number of short intervals at high target intensity, in what is typically referred to as the severe and extreme intensity domains [ 32 ], with long recovery periods in between the efforts. For the same relative power output, interval duration, total time spent at the target intensity or rest duration, the profile corresponding with the highest level of endurance (Time-Trialist) is subject to a higher percentage of impossible sessions than the athlete with a high anaerobic capacity (Sprinter).…”

“…The W′ reconstitution requires further work and individual adjustments [ 19 , 25 , 30 , 31 ]. At the foundation of the Skiba HIIT model, the continuous exercise hyperbolic model relies on a specific set of assumptions [ 25 ] restricting its validity to limited intensity and duration windows [ 32 ]. We suspect that the limitations of the hyperbolic model propagate to the Skiba HIIT model and confine its validity to certain intensity windows.…”

Using V̇o2max as a marker of training status in athletes—can we do better?

“…Thus, CP/CS, accompanied by the W’/D’, arguably gives an insight into performance capacity across a wider range of durations and exercise modalities than either V̇ o 2max or Wmax ( 28 ), or indeed any other measure of the heavy/severe exercise-intensity domain border ( 37 ). Indeed, the CP concept has been applied to predict performance across exercise durations from single repetition maximum ( 29 ) to marathon performance ( 27 ).…”

Determination of Critical Power Using Different Possible Approaches among Endurance Athletes: A Review

“…Testing protocols should mirror as closely as possible the competition settings to provide environmental validity. As an example, climbing specialists should perform prediction trials on a road bike in uphill conditions, while time trials specialists should conduct testing on a time trial bike on level ground [12].…”