Impact of exercise intensity and duration on metabolism during and post-exercise

Author

Ryan Jahanfar, Wilfrid Laurier UniversityFollow
Tom Hazell, Wilfrid Laurier UniversityFollow
Jessica Tucker, Wilfrid Laurier UniversityFollow

Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Kinesiology

Program Name/Specialization

<--Please Select Program Name/Specialization-->

Faculty/School

Faculty of Science

First Advisor

Tom Hazell

Advisor Role

Supervisor

Abstract

Abstract

INTRODUCTION: A common low-volume high-intensity interval training (HIIT) protocol involves repeating 1-min near-maximal bouts interspersed with 1-min rest 10 times within a session and has demonstrated greater excess post-exercise oxygen consumption (EPOC) than moderate-intensity continuous training (MICT). While typical MICT protocols (≥30 min) are longer than low-volume HIIT (20 min), yielding greater oxygen consumed (VO₂) during exercise, higher-volume HIIT protocols of similar duration to MICT (≥28 min) have been shown to elicit similar during-exercise VO₂ while eliciting greater EPOC. PURPOSE: To examine effects of extending the 20-min low-volume HIIT protocol to 30 min (by adding 5 additional exercise bouts) on overall VO₂ and post-exercise fat oxidation compared to MICT. METHODS: Nine recreationally active males (age: 22±4 y, V̇O_2max: 48.2±7.6 ml⋅kg^-1⋅min^-1, HR_max: 193±8 bpm) completed four randomized sessions: (1) no-exercise control (CTRL); (2) MICT (30 min at 60% VO_2max); (3) low-volume HIIT (10x1-min at 90% HR_max, 1-min rest); and (4) higher-volume HIIT (15x1-min at 90% HR_max, 1-min rest). Between-session differences for overall VO₂ and fat oxidation were assessed. RESULTS: V̇O₂ during exercise was elevated in all exercise sessions versus CTRL (P< 0.001). Overall session O₂ consumed was greater in all exercise sessions (MICT: 116.2±11.6 L; low-volume HIIT: 101.6±11.5 L; higher-volume HIIT: 126.9±8.8 L; P< 0.001, d< 7.17) compared to CTRL (52.4±10.9 L), while higher-volume HIIT was greater than both MICT and low-volume HIIT (P>0.001). Modified-HIIT and MICT increased fat oxidation post-exercise compared to CTRL (P< 0.015). CONCLUSION: Modifying low-volume HIIT with extra bouts to match MICT duration produces greater responses to exercise metabolism.

Recommended Citation

Jahanfar, Ryan; Hazell, Tom; and Tucker, Jessica, "Impact of exercise intensity and duration on metabolism during and post-exercise" (2026). Theses and Dissertations (Comprehensive). 2858.
https://scholars.wlu.ca/etd/2858

Convocation Year

2026

Convocation Season

Spring