#50 - HIIT, Fat Adaptation & Smarter Endurance with Dr. Paul Laursen
Today’s guest is Dr. Paul Laursen
How to turn overwhelming training science into simple, context-specific programming—so athletes and busy professionals can use HIIT, recovery, and fueling strategies that actually improve performance without burnout.
In today’s conversation Paul Laursen explores how to program high-intensity interval training by putting context before content, so sessions match a person’s sport, goals, and physiology. He and Dr. Wells break down when to use short vs. long intervals, why recovery choice (passive vs. active) changes what your muscles can do next, and how to monitor readiness with simple cues and HRV. They also dig into endurance nutrition, including fat-adapted approaches for long events and why “being a nutrivore” matters more than labels. Paul closes with Athletica.ai’s mission—making adaptive endurance plans practical for real life.
You will learn how to define HIIT precisely (above critical speed/power with structured recovery) and select interval formats that target the right systems for your sport. You’ll learn why context drives programming—from neuromuscular power work to VO₂-focused intervals—and how recovery type alters muscle oxygen re-loading to enable more quality work. You’ll hear a commonsense framework for endurance fueling, including when and why fat-adaptation can be useful, and how to individualize it. You’ll also learn practical monitoring ideas (readiness cues, HRV, and low-intensity “reset” days) and how adaptive tools like Athletica can translate theory into day-to-day training.
You will discover that choosing the right recovery between intervals (often passive, not active) can restore intramuscular oxygen (via myoglobin) and let you accumulate more truly high-quality work. That small switch can transform the same workout into a better stimulus with less grind.
It’s hard to navigate conflicting advice on HIIT, readiness, and nutrition. This episode gives a clear decision-tree—match the session to your goal, recover intentionally, and fuel for the demand—so training stops feeling random.
Key take aways:
Put context before content in every plan.
Recovery choice shapes the next interval’s quality.
Monitor readiness with HRV and simple body cues.
Fat-adaptation can help long-event performance.
Tools can adapt sessions to real life.
“The most important muscle in sport is the one between your two ears.”
Today’s Expert Guest - Dr. Paul Laursen
Dr. Paul Laursen is an endurance physiologist, coach, and entrepreneur best known as co-author of Science and Application of High-Intensity Interval Training and co-founder of Athletica.ai. He has served as an Adjunct/Associate Professor, coached athletes across multiple Olympic cycles, and authored 150+ scientific publications cited widely in sport science.
Laursen bridges rigorous lab research with practical coaching systems. Through HIIT Science he teaches a taxonomy of HIIT that maps session targets to sport demands, and through Athletica he operationalizes those principles into adaptive, readiness-aware training that scales from elite endurance athletes to time-crunched professionals.
Pick one key goal for your next training block, then design intervals—and the recovery between them—to serve that goal. For VO₂ focus, use short, high-quality reps with sufficient recovery (often passive) to keep power high; for neuromuscular power, keep sprints pure and fully recover; for endurance, bias longer efforts and fuel accordingly.
Follow Dr. Paul Laursen on Twitter & Linked In.
Check out his website.
Science and Application of High-Intensity Interval Training:
Solutions to the Programming Puzzle
Knowing the proper ways to incorporate high-intensity interval training into a fitness or conditioning program is of vital importance: Not following proper protocols can lead to excessive and prolonged fatigue, illness, or injury. Science and Application of High-Intensity Interval Training is an essential guide for those who want to incorporate HIIT into their own training or their athletes’ programming.
This podcast contains advice and information relating to health and wellness. It should be used to supplement rather than replace the advice of your doctor or another trained health professional. If you know or suspect that you have a health problem, seek your physician’s advice before embarking on any medical program or treatment. All efforts have been made to assure the accuracy of the information contained in this podcast / interview / article as of the date of publication. The author and publisher disclaim liability for any medical or other outcomes that may occur as a result of applying the methods suggested in this material.
