This narrative review by Martin Buchheit and Paul B. Laursen addresses the long‑standing “programming puzzle” of high‑intensity interval training (HIT) when the primary goal is to stress the cardiopulmonary system. The authors propose a unifying framework centred on the metric T@VO₂max – the cumulative time an athlete spends at or above 90 % of maximal oxygen uptake – and argue that maximising this exposure is the most direct route to improving VO₂max and related performance. They delineate nine inter‑related variables that define any HIT session (work intensity, work duration, recovery intensity, recovery duration, modality, repetitions, series, between‑series recovery, and total session volume) and show how systematic manipulation of these variables can be used to target specific T@VO₂max outcomes. Several prescription methods are compared, including absolute/relative speed (v/pVO₂max), the VInc.Test (incremental test‑derived speed), perceived exertion (RPE), and heart‑rate limits, with guidance on when each is most appropriate. The concept of Anaerobic Speed Reserve (ASR) is introduced as a tool for individualising interval intensity relative to an athlete’s sprint capacity. Field‑based tests such as the 30‑15 Intermittent Fitness Test (VIFT) and Yo‑Yo Intermittent Recovery Test are presented as practical means to estimate vVO₂max and to monitor training adaptations. The review synthesises a large body of experimental evidence showing that longer T@VO₂max, achieved through short work intervals, brief recoveries, and high intensities, yields superior VO₂max gains, while also discussing the physiological underpinnings (oxygen‑uptake kinetics, cardiac output, stroke‑volume maintenance) and the role of recovery modality (active vs. passive). The authors conclude with concrete programming recommendations for coaches seeking to design cardiopulmonary‑focused HIT protocols that are both effective and individually tailored.
Topics
T@VO₂max: Definition, Central Role, and Evidence for VO₂max Gains
Defines T@VO₂max as the cumulative time an athlete spends at ≥90 % of maximal oxygen uptake during a session. Explains why maximising this exposure is the most direct stimulus for VO₂max improvements and synthesises experimental evidence showing that protocols with short work intervals, brief recoveries, and high intensities produce longer T@VO₂max and superior aerobic adaptations.
Intensity Prescription Strategies: v/pVO₂max, VInc.Test, RPE, HR Limits, and Anaerobic Speed Reserve (ASR)
Compares four practical methods for prescribing interval intensity—absolute/relative speed (v/pVO₂max), incremental‑test‑derived speed (VInc.Test), perceived exertion (RPE), and heart‑rate limits—while introducing Anaerobic Speed Reserve as a tool to individualise interval speeds relative to an athlete’s sprint capacity.
Field‑Based Assessment Tools: 30‑15 Intermittent Fitness Test and Yo‑Yo Intermittent Recovery Test
Describes the protocols of the 30‑15 IFT and Yo‑Yo Intermittent Recovery Test, explains how they estimate vVO₂max and monitor changes in T@VO₂max, and highlights their utility as practical alternatives to laboratory testing for coaches and athletes.
Recovery Modality Impact on Oxygen‑Uptake Kinetics, Cardiac Output, and Sustaining High VO₂ Percentages
Reviews the physiological effects of active versus passive recovery on VO₂‑uptake kinetics, cardiac output, and stroke‑volume maintenance, and discusses how recovery modality influences the ability to sustain high percentages of VO₂max across intermittent bouts.
Practical Coaching Guidelines for Cardiopulmonary‑Focused HIT
Provides actionable recommendations for designing, monitoring, and adjusting HIT protocols that target cardiopulmonary adaptations. Integrates T@VO₂max targets, the nine session variables, intensity‑prescription methods (including ASR), field‑test feedback, and recovery‑modality considerations into a coherent programming framework.