Ben Greenfield
Ben Greenfield is a human-performance consultant, health coach, speaker, and New York Times bestselling author focused on fitness, nutrition, longevity, and biohacking. A 13-time Ironman triathlete, he co-founded the supplement company Kion and hosts the Boundless Life Podcast.
Zac Efron Says His ‘Iron Claw’ Transformation Was Too Costly to Repeat
Zac Efron said preparing for *The Iron Claw* meant eating about 6,000 calories a day, training at high volume and wrestling until he reached roughly 205 pounds—a routine he described as painful and said he never wanted to repeat. But he does not want that transformation to become the expectation for every role: he said he prefers work that changes what acting asks of him, including trying different genres and playing real people. During a lighter workout with Chris Williamson and trainer Ben Greenfield, he asked to keep the pace easy enough to talk and hang out.
Biohackers Rely on Personal Effects Where Device Evidence Is Thin
Chris Williamson and his guests argue that biohacking devices are often adopted on the basis of personal response rather than clinical evidence. They cite the BioCharger and WINBACK as examples of tools whose users report benefits despite unclear mechanisms and sparse data, while presenting roXiva, hyperbaric oxygen and hydrogen as interventions with more defined protocols but similarly experience-led claims.
GLP-1 Weight Loss Requires Muscle, Protein, and Strength Training
Dr Gabrielle Lyon, Ben Greenfield and healthcare entrepreneur Brigham Buhler argue that longevity medicine should begin with physical capacity—muscle, cardiovascular fitness, protein intake and mobility—rather than experimental interventions. They regard GLP-1 drugs, hormone replacement, peptides, stem cells and plasmapheresis as potentially useful but distinct tools whose evidence, product quality, dosing and oversight require more careful judgment. Their central concern is that medicine not reduce health to weight loss, a lab threshold or access to the newest treatment.