“You can’t play in the Premier League without good sprint distance”: Exploring the perceptions of professional soccer coaches in England on the usefulness and application of training load data

The aim of this case study was to explore professional youth soccer coaches in England's perceptions of training load variables and how the information can support their practice. Semi-structured interviews were conducted at a single soccer club with five academy coaches (U16-U23) with reflexive thematic analysis utilised to develop overarching themes within each central organising concept. Within the first concept of variable selection through principal component analysis, whereby coaches responded to examples of variable groupings and visualisations, coaches reported that this method was difficult to understand, yet the ability to show information on a 2D-scatterplot was appealing. Coaches typically reported high favourability towards variables such as total, high-speed, and sprint distances, however had little support for accelerations and decelerations. In the second concept of daily use, themes emerged for the use of training load data in the evaluation of session physical outputs, such as if players outputs were higher or lower than usual and using this information to make decisions for future training sessions and supporting their subjective observations. A final concept, longitudinal use, comprised of the themes relating to comparisons to first team training methodologies and load planning. Taken together, these results highlight the training load variables of importance to coaches alongside key concepts of their practice that sports scientists can support with appropriate feedback of data. How this information is utilised in data feedback processes, however, requires investigation. Furthermore, how these results are generalisable to coaches from alternate soccer clubs and age groups should be studied.