How do cycling coaches define and use training intensity distribution models?

Training load in cyclists can be quantified using a variety of methods and is often generalised into a model of training intensity distribution (TID) which may be defined by physiological constructs such as the lactate threshold or critical power (Hofmann and Tschakert, 2017, Frontiers in Physiology, 8, 145-153). Three common models are polarised, threshold, and pyramidal (Casado et al., 2022, International Journal of Sports Physiology & Performance, 17, 820-833). However, there is a lack of consensus regarding the training load quantification practices of cycling coaches. The aim of this study was to explore the practices and perspectives of cycling coaches on training load quantification, with specific reference to the use of intensity distribution models. Following institutional ethics approval an online survey was distributed to cycling coaches worldwide between March and June 2024. Questions covered knowledge and definitions of TID models, how training prescription was adapted depending on period of the season, how many zones they use, and if/how they track training load. 117 coaches (103 male, 14 female), with 13.2 ± 7.7 years’ coaching experience responded. The survey revealed that the most well-known TID model was polarised, recognised by 89.7% of respondents. The threshold model was known to 79.4% and the pyramidal model to 75.2%. Respondents near-universally described TID models using a three-zone method, despite most coaches stating they used 5-7 zones in their coaching. On average a polarised TID was described by coaches as consisting of 80.8%/3.3%/17.4% low/moderate/high intensity respectively. There was some inconsistency as to whether the polarised model should include any moderate intensity, the most common response defined polarised as 80%/0%/20% low/moderate/high. Pyramidal TID was described as including a decreasing percentage in each zone as intensity increased. Respondents defined pyramidal as 67.5%/23.4%/9.1% low/moderate/high on average. Across all models, respondents’ definitions of a threshold TID varied most. There was an increase in moderate intensity, although responses were split whether the highest percentage should be at low or moderate intensity. On average participants defined a threshold TID as 44.5%/44.0%/13.2% low/moderate/high. The responses from some coaches suggested their implementation of TID models was more flexible with adaptations made to change the intensity depending on factors such as training volume and experience. Further issues associated with implementing TID models are the uncertainty around how physiological measures delineating the intensities zones are determined as this could affect the reliability of zones and comparing TID models.