Greg Mack, a former nuclear submarine engineer, applies his systems thinking to human body optimization and injury recovery, working with elite athletes. He debunks physical therapy myths, emphasizing mental health's role in recovery. Mack advocates for movement over stretching, personalized recovery strategies, and the benefits of cold immersion for testosterone levels. He also examines blood flow restriction training and knee positioning in exercise, and discusses how yoga and Pilates can be tailored to athletes' individual needs.