HIIT vs. Zone 2: How Much Cardio Do You Actually Need? | Dr. Martin Gibala

If you only have a few hours a week to train, how much should you spend on Zone 2? Exercise scientist Dr. Martin Gibala joins Ben Pakulski to explain what the evidence supports for improving cardiovascular fitness when time is limited. Want a training plan built around your goals, schedule and recovery? Apply to work with my team Preregister for the Muscle Intelligence Coach's Mentorship: https://bit.ly/4sUFCT2 Elite endurance athletes often spend most of their training time at lower intensities. But does their 80/20 split make sense for someone training two hours a week? Gibala explains why that recommendation deserves a closer look, and how to think about intensity beyond the zones on your watch. In this episode, you'll learn: Why 3 to 5 minute intervals are a strong option for improving VO₂ max. What "vigorous" effort actually feels like, using a simple 1 to 10 scale. Where exercise snacks showed blood sugar benefits, and why at-home trials didn't reproduce the fitness gains seen in the lab. How short sprints and longer intervals create different training demands. What to consider about cardio, muscle retention and GLP-1 medications. For coaches: Learn to assess the individual and build a plan they can succeed with. Apply to the MI Coaches Mentorship. About Dr. Martin Gibala Dr. Gibala is a professor of kinesiology at McMaster University, author of The One-Minute Workout, and co-host of the Exercise Science podcast with Dr. Stuart Phillips. Chapters 00:00 Dr. Gibala's Path Into Exercise Science 13:09 Exercise Snacks and the One-Minute Workout 23:51 How Exercise Scientists Measure Fitness 34:45 How Hard Is Vigorous? The 1 to 10 Scale 38:18 Intervals for Improving VO₂ Max 43:21 Training Zones and Metabolic Thresholds 53:35 Does the 80/20 Split Fit Your Schedule? 59:54 Cardio, Muscle and GLP-1s 1:08:08 Where to Find Dr. Gibala Connect with Dr. Martin Gibala Website: www.martingibala.com Instagram: https://www.instagram.com/gibalamj/ X: https://x.com/gibalam The Exercise Science Podcast: Website: www.realexercisescience.com Spotify: https://open.spotify.com/show/29lBGiRrOMSaN5cjy4e1vK?si=4cf6c9ad47ea4415 Apple Podcasts: https://podcasts.apple.com/us/podcast/exercise-science/id1885632210 YouTube: https://www.youtube.com/@realexercisescience Facebook: https://www.facebook.com/realexercisescience/ TikTok: https://www.tiktok.com/@realexercisescience Instagram: https://www.instagram.com/realexercisescience/ Threads: https://www.threads.com/@realexercisescience X: https://x.com/realexscience BlueSky: https://bsky.app/profile/realexscience.bsky.social Connect with Ben https://benpakulski.com https://muscleintelligence.com https://instagram.com/bpakfitness https://x.com/bpakfitness https://facebook.com/BenPakulskiMuscleIntelligence