#50 - HIIT, Fat Adaptation & Smarter Endurance with 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.