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The Science of Fitness and Mitochondria: The Source of Inner Power

By: , Posted on: November 13, 2014

The Science of FitnessThe Science of Fitness: Power, Performance, and Endurance is a compelling look into the biological process of fitness, sports nutrition, and human endurance by two-time World Champion and Winner of the Tour de France, Greg LeMond, and Dr. Mark Hom. The book clearly explains the vital connection between diet and exercise in the human body. With this knowledge, you can use the right exercise and nutrition to obtain a higher quality life, prevent disease, and slow the aging process. Whether you are interested in how to eat healthy, train for your first (or next) marathon, take your fitness to the next level, find the best super foods, or simply want to improve your vitality through healthy, doable practices, this book will help you on your journey regardless of age or fitness level.

Below, you will find some commentary from Dr. Mark Hom on mitochondria, every athlete’s inner power.


Mitochondria: The Source of Inner Power

Deep inside your body and inside your cells, energy is generated. Not only do mitochondria power every athletic endeavor, they also energize the body keeping it vibrant and healthy. If you do everything you can to support your mitochondria, you will benefit by having more power, performance, and endurance. “Mitochondria” is a term some athletes have not used since high school biology. Because they are so important, mitochondria should be as common in athletes’ vernacular as “carbohydrate” or “protein.” Mitochondria are the masters of oxygen. They are able to use the reactivity of the oxygen molecule to turn food and body fat into the energy that muscle can actually use. Without mitochondria, you literally could not lift a finger. Mitochondria are the tiny descendants of bacteria that inhabit each of your cells in a mutually beneficial symbiotic relationship. We need mitochondria (they provide us with energy) and mitochondria need us (we provide them with oxygen and nutrients). How mitochondria came to be within our cell goes way, way back in primordial evolution when our ancient ancestors were still at the single cell stage. Before mitochondria, organisms merely existed. With the energy provided by mitochondria, they could truly thrive.

We are largely what we are due to this endosymbiotic relationship. Although some find it disturbing that we are related to primates, we are bizarrely conglomerations of two types of life forms: cells and bacteria. The evidence includes the fact that mitochondria have their own distinct DNA, separate from the cell’s nuclear DNA. Unlike other genes that are inherited from both parents, we inherit our mitochondria solely from our mothers. Even though professional sports focuses on male competition, we get our more of our athletic metabolism from our mothers. In a nod to biology, George Lucas used intracellular symbionts (what he called midi-chlorians) to explain why some “Star Wars” characters were more endowed with the Force. In a similar way, mitochondrial density explains why star athletes have more energy.

Mitochondria generate your cells’ energy. In an orchestrated series of chain reactions, mitochondria generate ATP (adenosine triphosphate), the chemical driving force behind cell function, muscular power, and cardiac output. The vast majority of human energy comes from ATP generated within mitochondria, which are therefore the key in understanding athletic performance.

The final step in the production of ATP involves the most intricate enzyme known in biology. Driven by the proton battery inside each mitochondrion, ATP synthase churns out ATP using a high-revving nanomotor mechanism. Whereas most other enzymes are made of a single protein, ATP synthase is a complex of 31 proteins, with several parts analogous to the machinery in a high-performance automotive engine including: a cam shaft, high speed rotors, pumping action, and reverse gearing. Variations of this enzyme give vitality to virtually every form of life on Earth. It is also the athlete’s engine.

Inside the Mitochondrion


Read more from Greg LeMond and Dr. Hom on Elsevier Connect!

About the Authors

Greg LeMondGreg LeMond is a legendary and pioneering bicyclist, three-time winner of the Tour de France (1986, 1989, and 1990), three-time World Cycling Champion (1979, 1983 and 1989), author, founder of the LeMond Fitness company, bicycle technology innovator, and fitness expert. Greg LeMond runs his company, LeMond Fitness Inc., and is a leader in the latest training equipment. He works closely with leading sports physiologists (such as Adrie Van Diemen, physiologist for Team Garmin) in the development of power training devices. In addition, he contributes in many cycling periodicals, most recently Cycling News.


MarkHomDr. Mark Hom is a Johns Hopkins University trained biologist, an award winning medical illustrator, an interventional radiologist applying high technology to the diagnosis and treatment of his patients, an educator of young doctors, and an avid fitness cyclist. Dr. Hom’s work explains how the human body, various organ systems, and individual cells function in the biologic process of exercise.

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Biomedicine & Biochemistry

The disciplines of biomedicine and biochemistry impact the lives of millions of people every day. Research in these areas has led to practical applications in cardiology, cancer treatment, respiratory medicine, drug development, and more. Interdisciplinary fields of study, including neuroscience, chemical engineering, nanotechnology, and psychology come together in this research to yield significant new discoveries. Elsevier’s biomedicine and biochemistry content spans a wide range of subject matter in various forms, including journals, books, eBooks, and online information services, enabling students, researchers, and clinicians to advance these fields. Learn more about our Biomedical and Biochemistry books here.