Sport Sciences and Health Research

Sport Sciences and Health Research

Comparison of Time Spent ≥90% VO₂max Between Fast-Start and Traditional High-Intensity Interval Training in Recreationally Trained Male Endurance Runners

Articles in Press

Document Type : Research Paper

Authors
abdolrahman ghazzagh
ashkan koushki
hamid aghaalinejad
Department of Sport Sciences, Faculty of Humanities, Tarbiat Modares University
10.22059/sshr.2026.411174.1243
Abstract
High-intensity interval training (HIIT) is a well-established method for improving aerobic capacity and maximal oxygen uptake (VO₂max). This study aimed to compare the acute physiological and perceptual responses between traditional and fast-start HIIT protocols in recreationally trained male endurance runners. Twenty recreationally trained male runners (age: 35.5 ± 6.1 y; VO₂max: 50.8 ± 5.8 mL·kg⁻¹·min⁻¹) completed two treadmill-based HIIT sessions in a randomized crossover design. The traditional HIIT consisted of three 4-min intervals at 92% vVO₂max with 3-min passive recovery, while the fast-start HIIT involved three 4-min intervals beginning with 2 min at 100% vVO₂max followed by 2 min at 84% vVO₂max, with the same recovery duration. Pulmonary gas exchange, blood lactate concentration, heart rate, and rating of perceived exertion were measured. The fast-start HIIT elicited a significantly greater T@≥90%VO₂max than the traditional HIIT (463.7 ± 143.6 s vs. 423.0 ± 178.5 s; p = 0.043, d = 0.35), representing an approximate 9.6% increase. No significant differences were found for relative VO₂, VO₂peak, blood lactate concentration, mean or peak heart rate, or RPE between protocols. Fast-start HIIT increases the time spent near maximal oxygen uptake without imposing additional cardiovascular, metabolic, or perceptual strain.
Keywords
High-intensity interval training
VO₂ kinetics
pacing strategy
oxygen uptake
endurance runners
Sport Sciences and Health Research

Articles in Press, Accepted Manuscript
Available Online from 03 November 2026