Effects of different aerobic high-intensity interval training prescription approaches on cardiorespiratory fitness and performance in distance runners (PhD Academy Award)

Abstract

The aim of my PhD was to investigate how different approaches to prescribing aerobic high-intensity interval training (HIIT) influence cardiorespiratory fitness and performance in distance runners. Specifically, I compared three methods: a physiological approach (PHY), which individualises intensity using the Delta concept, based on the second lactate threshold (vLT2) and peak treadmill speed (Vpeak); a race pace-based approach (RACE), which sets intensity relative to target (10 000 m) race speed; and a standardised ‘one-size-fits-all’ approach (STD), in which all runners followed the same group-based training protocol, irrespective of individual physiological characteristics. The comparisons PHY versus RACE and PHY versus STD were treated as distinct research questions. This project sought to determine whether laboratory-based, physiologically individualised HIIT prescriptions are more effective at improving cardiorespiratory fitness than more commonly used, less individualised approaches. Moreover, I investigated whether prescribing HIIT based on race pace optimises performance compared with physiological prescriptions. Finally, I explored the variability in Vpeak and 10 000 m speed at vΔ50 (the speed midway between vLT2 and Vpeak) to assess whether these could serve as simpler alternatives to the Delta concept for individualising HIIT. The rationale for my PhD is illustrated in figure 1. Outside the experimental part of my PhD, I also reviewed the use of equivalence and non-inferiority designs to complement or replace traditional null hypothesis testing, aiming to …