489: Bill Smart on Isometrics, Flywheels, and Elastic Power Development

Today’s guest is Bill Smart. Bill is a sport scientist and physical preparation coach specializing in elite fight-sports performance. As the founder of Smarter Performance and the Strength & Conditioning lead for the CORE MMA team, Bill integrates cutting-edge evidence with real-world high-performance systems to enable combat athletes to show up on fight day in optimal physiological condition. Much of the conversation in sports performance hinges on speed and power development, or conditioning, as a stand-alone conversation. Sport itself is dynamic and combines elements of speed, strength, and endurance in a dynamic space. Training should follow the same considerations to be truly alive and effective. In the episode, Bill shares his journey from cycling and rowing to combat sports. He discusses how long isometric holds develop both physical and mental resilience, and their implementation in his programming. The conversation dives into muscle-oxygen dynamics, integrating ISOs with conditioning, and how testing shapes his approach. Bill also explores flywheel eccentrics, fascicle-length development, and why sprinting is a key element for maintaining elastic power in elite fighters. Today’s episode is brought to you by Hammer Strength and the Just Fly Sports Online Courses 30-50% off all courses until December 1, 2025. (https://justflysports.thinkific.com) Use code “justfly10” for 10% off the Vert Trainer Use code “justfly20” for 20% off of LILA Exogen Wearable resistance gear at www.lilateam.com View more podcast episodes at the podcast homepage. (https://www.just-fly-sports.com/podcast-home/) Timestamps 0:00 – Bill’s coaching journey and early mentors 6:04 – The importance of movement observation and intuition 11:35 – Why athletes plateau and how to identify limiting factors 20:42 – Strength training principles that actually transfer 30:01 – Using movement variability and play in training 40:36 – Coaching communication and creating connection 52:09 – The role of curiosity and creativity in coaching longevity 1:00:55 – Key lessons from years of coaching experience Actionable Takeaways 6:04 – Movement observation and intuition Bill emphasizes that the best coaches develop a trained eye for movement by observing, not just testing. Watch athletes move in multiple contexts before prescribing anything. Look for how they transition between patterns, not only the end positions. Use video less for judgment and more for curiosity. What is the athlete trying to do? 11:35 – Identifying limiting factors Athletes plateau when coaches overemphasize one metric or capacity while ignoring the real constraint. Look beyond the weight room; technical or psychological factors often drive plateaus. Use minimal testing data to narrow focus rather than justify complexity. Sometimes the limiting factor is overcoaching. Let athletes fail and self-correct. 20:42 – Strength that transfers Transfer happens when strength work complements, not competes with, the sport’s rhythm and intent. Prioritize strength that preserves elasticity and timing rather than just force output. Rotate exercises often enough to keep athletes adaptive, but not so often that they lose rhythm. Load movement patterns, not just muscles. Treat every lift as coordination under resistance. 30:01 – Variability and play in training Bill describes play as a teaching tool that restores creativity and problem-solving in athletes. Use small games, uneven surfaces, or timing constraints to build adaptable movers. Variability should be purposeful. Expand coordination bandwidth without losing technical intent. Schedule “uncoached” time in sessions where athletes explore movement freely. 40:36 – Coaching communication and connection Great coaching depends on trust and empathy before information transfer. Deliver feedback as collaboration,