About the Book
Force 3 reframes endurance performance through a mechanical lens, showing why force expression – not just aerobic capacity – governs how fast an athlete can move over a given distance. The book explains that endurance events are, at their core, problems of productive power output: athletes must perform a fixed amount of mechanical work, and the rate at which they can do that work determines their performance. This leads to a series of counterintuitive insights, including the surprising importance of strength, the influence of technique on energy use, and the way efficiency connects the mechanical and metabolic sides of performance.
The book digs into how chemical energy becomes mechanical work and why athletes vary so widely in the proportion of their available energy they can turn into useful movement. It examines the mechanical consequences of mass and mass distribution, showing why certain athletes appear to “float” while others seem to fight the ground or water. It also explains why the forces that create speed are the same forces that create injury risk, and why understanding force expression is essential for both performance and resilience. These ideas become concrete through two detailed case studies in running and rowing, demonstrating how strength work, technique refinement, and efficiency-focused training combine in real, high-level programmes.
And throughout, the book maintains a practical orientation. It gives endurance athletes and coaches a way of thinking about performance that complements – rather than replaces – traditional physiology. Where physiology describes how much energy is available, mechanics describe how effectively that energy becomes movement. Force 3 shows how both perspectives can work together to produce better decision-making, clearer reasoning, and more effective training design across endurance sports.
What You'll Learn
You’ll learn why productive mechanical power output is the central variable linking movement mechanics, physiology, and race outcomes. The book describes how endurance athletes convert chemical energy into mechanical work, how much of that work becomes forward motion, and why efficiency emerges from technique, tissue characteristics, and coordination as much as from aerobic capacity. This makes it clear why athletes with similar VO₂ max values can perform very differently, and why efficiency gains can produce meaningful improvements even when aerobic development has slowed.
You’ll understand how body mass and mass distribution influence both performance and energy cost, and why the “optimal” amount of muscle depends on the forces required by the event. The book explains the many mechanisms through which strength training can improve endurance performance: greater maximal force capabilities, improved efficiency, increased stride or stroke effectiveness, better force expression at extended ranges of motion, and improved resilience under fatigue. You’ll also see how strength training interacts with movement economy and how mechanical improvements can reduce both external work and energetic cost over a given distance.
Importantly, you’ll learn how these principles apply to real sport. The running and rowing case studies show how power output, efficiency, and technical constraints shape training decisions, and how strength work can be integrated without compromising endurance development. The book also explains the mechanical basis of injury – how forces accumulate, how tissues adapt, and why some injuries occur even when energy is still available. By the end, you’ll have a comprehensive framework for understanding endurance performance from first principles, allowing you to design training that targets the variables that actually matter.
Who the Book Is For
This book is for endurance coaches, strength and conditioning practitioners, sport scientists, and motivated athletes who want to understand performance through mechanics rather than relying on tradition or surface-level physiological explanations. It’s written for readers who are willing to think about training in terms of force, work, and efficiency but who do not necessarily have a formal background in biomechanics. The explanations are clear and accessible, with each key concept introduced step-by-step so that readers can follow the reasoning without needing advanced mathematics or physics.
It’s also for coaches and athletes who want a more coherent rationale for incorporating strength training into endurance programmes. The book provides a mechanical argument for how strength work can improve performance – not simply as “support” or “injury prevention,” but as an intervention that can improve force production, efficiency, technique, and resilience. Whether you work with runners, rowers, cyclists, or mixed-endurance athletes, Force 3 helps you understand why athletes differ, how to diagnose their mechanical strengths and limitations, and how to select training that meaningfully shifts the variables that determine performance.
More broadly, the book is for anyone who wants to think more clearly about endurance sport. It will appeal to coaches who want to connect physiology with mechanics, to athletes who want to understand the “why” behind their training, and to professionals who value reasoning grounded in physical principles. If you’re looking to move beyond clichés about “engine size” and instead understand how movement, force, and energy interact to produce real performance, this book gives you the conceptual tools to do it.
About Dan Cleather
Dan Cleather has spent most of his life trying to understand how people get better at the things they care about. Sometimes that has meant coaching athletes in weight rooms and on tracks; sometimes it has meant teaching critical thinking and research skills; sometimes it has meant writing books to make sense of training in a way that feels human rather than mechanical.
His work has always followed the same thread: training is a process of change, not a set of rules. Bodies learn, adapt, and reorganise themselves over time, because that is what the are designed to do. He tries to help people see that process more clearly - coaches, athletes, teachers, and anyone interested in long-term development.
Over the years he has worked across elite sport, academia, and high-performance environments, including the English Institute of Sport, St Mary’s University, and as a collaborator with national space agencies. Those experiences shaped his interest in how stress, rhythm, coordination, and load interact to produce real, durable change.
The Training Wisdom Collection brings this work together: a set of books, courses, and resources built on first principles rather than trends. The aim is not to provide a system to follow, but a set of tools to think with - a way of making sense of training that respects both physiology and practice, theory and craft.
He lives in Prague, where he writes, teaches, and continues to explore how people learn, move, and adapt.
About The Training Wisdom Collection
The Training Wisdom Collection began as an attempt to make sense of the ideas that kept returning in coaching conversations - the patterns that sit underneath good training, regardless of method or sport. Over time it grew into a set of books and courses that approach training from first principles, not fashion.
The Collection isn’t a system. It doesn’t claim to reveal the hidden truth of strength and conditioning or promise a shortcut to progress. Instead, it tries to show how training actually works: how bodies learn, how stress and rhythm shape adaptation, how coordination becomes skill, and why long-term development depends more on clarity and patience than on novelty.
Each book takes a different angle on that same problem. The Little Black Book of Training Wisdom was the starting point - a compact attempt to explain why simple principles matter, and the thread that runs through everything that followed. The Practice of Change looks at the rhythms of work and recovery that shape adaptation. The Force series examines how movement and load interact. The courses take these ideas into practice, turning them into tools a coach or athlete can use straight away.
The aim is simple. Training should feel understandable. It should have a shape that makes sense. And it should help people build capacities that last longer than the programmes they come from. The Training Wisdom Collection exists to offer that kind of clarity - not by reducing training to rules, but by giving people a language that reflects what actually happens when bodies change.
