This five-study thesis aimed to establish the comparative effectiveness, optimal application and clinical transferability of isometric exercise training (IET) to better understand its potential role in future exercise guideline recommendations. Study 1 laid the foundations for the thesis with a large-scale comparative systematic review and network meta-analysis comparing IET against other guideline-recommended traditional exercise approaches.1 This study has subsequently informed changes to current practice recommendations in the European hypertension guidelines (2024 ESC, ESE, ESO, Section 8.2.2).2 Study 2 aimed to then determine the most effective application of IET in a randomised cross-over design trial. After establishing the comparative effectiveness and most effective applications of IET, studies 3, 4 and 5 then moved onto the transition of IET into clinical populations exhibited with a randomised controlled clinical trial investigating the acute and chronic effects of IET in pa

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 approa