In this presentation from 2009, Greg Glassman succinctly explains to his staff why his fitness program is so effective, and why it is a scientific breakthrough.
Coach Glassman explains that the essence of CrossFit is nicely contained within our definition of functional movement, and our commitment to their exclusive use. The movements are safe, natural and compound in nature—and they’re efficient. They express power and lend themselves to precise measurement. That measurement is key, because it takes fitness out of the realm of ethereal guesswork and makes it concrete and quantifiable. When something can be defined and measured, ideas can be tested and improvement can be tracked, allowing athletes and trainers alike to find the best way to achieve fitness.
“What we are doing collectively…is we are building a technology of advancing human performance.”
This video, by BSI’s co-founder, was originally published in The CrossFit Journal. While Greg Glassman no longer owns CrossFit Inc., his writings and ideas revolutionized the world of fitness, and are reproduced here.
Coach Glassman named his training methodology ‘CrossFit,’ which became a trademarked term owned by CrossFit Inc. In order to preserve his writings in their original form, references to ‘CrossFit’ remain in this video.
Greg Glassman founded CrossFit, a fitness revolution. Under Glassman’s leadership there were around 4 million CrossFitters, 300,000 CrossFit coaches and 15,000 physical locations, known as affiliates, where his prescribed methodology: constantly varied functional movements executed at high intensity, were practiced daily. CrossFit became known as the solution to the world’s greatest problem, chronic illness.
In 2002, he became the first person in exercise physiology to apply a scientific definition to the word fitness. As the son of an aerospace engineer, Glassman learned the principles of science at a young age. Through observations, experimentation, testing, and retesting, Glassman created a program that brought unprecedented results to his clients. He shared his methodology with the world through The CrossFit Journal and in-person seminars. Harvard Business School proclaimed that CrossFit was the world’s fastest growing business.
The business, which challenged conventional business models and financially upset the health and wellness industry, brought plenty of negative attention to Glassman and CrossFit. The company’s low carbohydrate nutrition prescription threatened the sugar industry and led to a series of lawsuits after a peer-reviewed journal falsified data claiming Glassman’s methodology caused injuries. A federal judge called it the biggest case of scientific misconduct and fraud she’d seen in all her years on the bench. After this experience Glassman developed a deep interest in the corruption of modern science for private interests. He launched CrossFit Health which mobilized 20,000 doctors who knew from their experiences with CrossFit that Glassman’s methodology prevented and cured chronic diseases. Glassman networked the doctors, exposed them to researchers in a variety of fields and encouraged them to work together and further support efforts to expose the problems in medicine and work together on preventative measures.
In 2020, Greg sold CrossFit and focused his attention on the broader issues in modern science. He’d learned from his experience in fitness that areas of study without definitions, without ways of measuring and replicating results are ripe for corruption and manipulation.
The Broken Science Initiative, aims to expose and equip anyone interested with the tools to protect themself from the ills of modern medicine and broken science at-large.
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Metabolic health, medical education, and the case for bringing clinicians and coaches together
At the 2026 Unbreakable Health Retreat in Miami, Emily Kaplan hosted a panel with Bob Kaplan, Professor Thomas Seyfried, and Dr. Derek Lee on what it means to treat cancer as a metabolic disease. They discussed the glucose-ketone index (GKI), nutritional ketosis, and strategies aimed at restricting the fuels cancer cells depend on while considering how metabolic therapy can fit alongside standard cancer treatment.
The conversation also addressed the practical realities patients face when trying to pursue a metabolic approach within the conventional oncology system, including questions about nutrition, repurposed drugs, inherited cancer risk, and how to evaluate different treatment options. Seyfried and Lee connected these clinical questions back to mitochondrial dysfunction, fermentation, and the metabolic vulnerabilities that may offer additional targets for cancer treatment.
An abbreviated version of this discussion is available here, for free.
At the 2026 Unbreakable Health Retreat in Miami, Professor Thomas Seyfried presented the case that cancer is fundamentally a mitochondrial metabolic disease rather than primarily a genetic one. He contrasts the dominant somatic mutation theory with a metabolic model in which impaired mitochondrial respiration drives a shift toward fermentation, dysregulated cell growth, and the mutations commonly associated with cancer.
Citing the work of Otto Warburg and research from his lab at Boston College, Seyfried explains how cancer cells rely heavily on fermentable fuels—particularly glucose and glutamine—and why mitochondrial dysfunction sits upstream of many of the genetic abnormalities seen in tumors. He also discusses reactive oxygen species, altered cellular signaling, and the role of mitochondria in regulating cell growth and behavior.
The presentation then turns to the therapeutic implications of this model. Seyfried explains strategies aimed at placing tumor cells under metabolic stress by restricting the fuels they depend on, including ketogenic metabolic therapy and approaches targeting glucose and glutamine. For Seyfried, the therapeutic target follows directly from the biology: restrict the fuels cancer cells depend on, exploit their metabolic weaknesses, and treat mitochondrial dysfunction as the central feature of the disease.
An abbreviated version of this discussion is available here, for free.
MetFix and BSI Members can view the full 54-minute video.
