Determinants of middle-distance performance in youth swimmers

The 200- and 400-m performances share the same putative physiological determinants as they sit within the upper part of what physiologists have named the ‘severe intensity domain’. The present chapter begins with an introductory framework for an in-depth understanding of the main energetic determinants of the middle distances, i.e. anaerobic capacity and maximal aerobic power. Both determinants are then examined further alongside other key determinants of severe-intensity performances of the young swimmers, i.e. their physical characteristics, swimming efficiency, ability to resist fatigue, all affecting the stroking parameters. This second part of the chapter includes key definitions and methods of assessment with consideration of reliability, validity, sensitivity and applicability when working with young swimmers. Practitioners are encouraged to use some of these methods to monitor changes during seasons and career and assess in doing so, the effectiveness of their training programmes.