Muscle, miles, and the honest ceiling

In 2017, a man in his fifties sat on a Concept2 indoor rower, set the clock to sixty seconds, and pulled the handle four hundred and three metres before the timer stopped. His name was Shawn Baker, and by his own account he had eaten almost nothing but red meat for a year and a half.

Baker's route to that machine reads like a warning label for a lot of men in their forties. Orthopedic surgeon, biology degree from the University of Texas at Austin, medical school with honours at Texas Tech, five-year surgical residency, later chief of orthopedics at multiple U.S. Air Force bases (biographical record on his own site). On paper, thriving. In practice, by his mid-forties he was reportedly gaining forty to fifty pounds, sleeping badly enough to be diagnosed with sleep apnea, dragging a stiff back and knees into the operating room, and picking up markers of metabolic disease. "I was most likely developing metabolic disease. And I didn't like that," he told Unfiltered in a long interview about the years around his transition.

He tried the standard fixes first. Calorie-restricted low-fat, high-fibre plates through his thirties left him thinner and, in his own word, miserable. Then keto. Then a stricter ketogenic protocol. In late 2016 he tightened the aperture again and cut plants entirely. "At the end of the 30 days it was remarkable to me how good I felt," he says of that first month. "It was really, literally, the best I'd felt for as long as I could remember, certainly several decades."

He kept going. Today he describes his intake as roughly ninety-five to ninety-seven percent red meat, mostly beef, with eggs, cheese and seafood filling the rest. "In the last seven years my diet has been probably 97% red meat, particularly beef. That's no exaggeration," he told the same interviewer.

What sits underneath the record book is worth naming, because it changes what those records actually prove. Baker's powerlifting résumé is deep. A 772-pound deadlift American record in 2000. A 738-pound sub-master world record. A 711-pound Masters lift in 2007. Highland Games Masters World Champion in 2010. All of it set on mixed diets, years before he cut plants. The clean carnivore-era claim is narrower. In his fifties, on carnivore, Baker began setting Concept2 Masters world records on the indoor rower in his own age bracket in the years after transitioning, and Concept2 itself featured him in that era as an athlete who "likes to break records, including his own, over and over again." Whether every one of those Masters records still stands today is a moving target; Concept2's rankings rotate. What isn't a moving target is the physical fact of the effort. A man in his fifties, on beef, still pulling.

Baker also lost his New Mexico medical license in 2017, in a matter separate from his diet advocacy but worth naming once, since he still trades on the "Dr." prefix. He is a diet advocate with commercial interests, co-founder of the Revero clinic and author of a book on the diet, not a neutral clinician. Take his account as one experienced practitioner's testimony, not as evidence about anyone else.

The strength community's long-haul voices

Baker is the loudest voice in strength on carnivore, but he isn't the longest tenured one. That title probably belongs to Kelly Hogan, a woman who has been eating close to zero carbohydrate since 2004, more than twenty years by now, and who runs the community site My Zero Carb Life. Hogan says she lost roughly a hundred and thirty pounds from a starting weight of 262. She then added weight training on top of it and reports building meaningful muscle in her forties on a diet that carries near-zero plant matter. Both figures come from her own account across long-form podcast interviews. "Fifteen years, still training, still eating this way" is roughly how she frames it. That is not a controlled study. It is one person's testimony over a very long window, which in a young community is worth something on its own.

At the competitive end, the honest case is thinner. Robert Sikes, known online as Keto Savage, has earned a natural pro card in bodybuilding and written a book on ketogenic bodybuilding. He is not carnivore. His protocol is a strict, high-fat ketogenic build with nutrient-dense whole foods, and he belongs in this piece only as adjacent evidence: muscle can be gained without the heavy carbohydrate loading most bodybuilders live on. That is not evidence that all-meat, specifically, does the same.

Alongside them sits Bart Kay, a former senior lecturer in cardiovascular and respiratory physiology who has consulted with the New Zealand All Blacks, the NRL Referees Association, and defence forces on both sides of the Tasman. Kay reports following the diet for close to a decade. He is polarising in the online space and worth reading as a credentialed advocate rather than a neutral analyst; the credential earns a hearing, not automatic agreement.

Endurance is where the honest picture gets uncomfortable

The elite endurance world's most-cited low-carb success story is the American ultra-runner Zach Bitter, who ran the 100-mile world record on 25 August 2019 at a 6:48-per-mile pace. Bitter is not carnivore. He describes himself as fat-adapted and animal-based, but his baseline training diet carries 100 to 150 grams of carbohydrate a day, and he ramps that considerably higher during racing. That is the closest the elite endurance ranks get to the meat-only end of the spectrum, and it is still not there.

Strict-carnivore elite endurance, as of the record book today, is essentially absent. Search the low-carb endurance space and the names that surface (Bitter, Peter Attia's cycling, various fat-adapted triathletes) all flex carbohydrate deliberately in and around competition. The strict-carnivore endurance stories that do exist live at the community and amateur level. Coach Stephanie Holbrook, who trains in the 70.3 triathlon distance, describes fat-adapted improvements on a meat-heavy but not strictly all-meat protocol. The MeatRx success-story archive contains a handful of ultra-distance and long-course runners who report training and racing on all-meat, though most declare distances and finish times rather than podium places.

The honest sentence is this. Strict-carnivore endurance at the elite tier is a story that hasn't been written yet. The strength story has an anchor and a decade-long practitioner. The endurance story has forums, testimony, and one Ironman-adjacent coach's blog. That does not mean nobody is competing well on meat. It means the record book has not caught up, and any claim otherwise is running ahead of the evidence.

What the science says, and doesn't

Two lines of research bracket the honest ceiling. On one side, Jeff Volek's FASTER study, published in Metabolism in 2016, compared elite low-carb ultra-runners and Ironman triathletes to their high-carb peers over an average of twenty months on their respective diets. The fat-adapted athletes oxidised fat at up to double the rate of the high-carb group while maintaining normal muscle glycogen. The important caveat, which Volek's own group makes clear, is that FASTER measured metabolism, not race performance. It shows fat-adaptation is metabolically real. It does not show that eating this way wins races. And low-carb in Volek's cohort was not carnivore. Read FASTER as ceiling evidence, not proof.

On the other side sits the work of Iñigo San-Millán, the exercise physiologist behind Tour de France winner Tadej Pogačar, who appears in a long conversation with Peter Attia on the same podcast. San-Millán's argument, distilled, is that the athletes at the very top of endurance sport carry both metabolic gears at once. A well-developed capacity to oxidise fat. And an equally developed capacity to handle glucose. Carbohydrates are not the villain the strictest end of the low-carb world sometimes casts them as. They are a tool elite athletes use in specific windows.

Both things are true at once. Fat-adaptation is a real physiological state. And the athletes who win at the top of endurance carry two fuel systems, not one. A carnivore protocol optimises for the first at the cost of the second. That trade-off is what the current record book actually shows.

What holds, what doesn't

Where the evidence is firm, name it. Where it is anecdote, say so.

• Multiple lifters and long-tenure practitioners maintain and gain muscle on very-low-carb and all-meat protocols. Baker, Hogan and adjacent low-carb cases like Sikes are individual reports, not controlled trials.
• Fat-adaptation is a measurable metabolic state and shows up in careful physiology. It has not been shown to translate into race wins in elite endurance sport.
• Community reports of recovery, joint-pain reduction and inflammation change are common enough to be worth taking seriously as testimony. They are still individual experience, not population-level effects.
• "The carnivore diet builds strength" is a community sentence, not a scientific one. So is "carbs aren't necessary for peak endurance."

That is where the ground is. The rest is a story a lot of people are still writing, one plate at a time.