Passing the Torch- The Ketogenic Diet Part 12

I recently had the chance to try another experiment on my body. This one did not involve transfusions, extractions, modifications, or harvesting. It was a metabolic test, specifically an anaerobic threshold test, designed to measure how efficiently I burn fat under exercise load.

How the test works

You wear a mask connected to a gas analyzer that measures the oxygen and carbon dioxide in your expired breath. From the ratio of those two gases, the technician can tell when your body is shifting from fat as its primary fuel source toward carbohydrate as its primary fuel source.

The point of training, especially for endurance work, is to stretch the fat burning phase as long as possible. Carbohydrate utilization starts when you can no longer supply enough oxygen to burn fat to make the energy you need. That is anaerobic metabolism, meaning “without oxygen.” Hold your breath for two minutes and you know what that feels like.

The crossover moment is called the lactate threshold. Below it, you can clear metabolic waste fast enough to keep using fat efficiently. Above it, you start leaning on carbohydrate, and your time to exhaustion is suddenly counted in minutes.

What my numbers showed

I stayed in fat burning mode for at least 24 minutes at 8.5 mph (just over a 7 minute mile pace) at 6 degrees of incline. We extrapolated VO2 max from the data. The number was already 125% of a normal VO2 max for a man my age when the test ended, and it suggested I can hold roughly 85% effort and still be in the fat burning zone.

That is a strong number. It is not because I have superior genetics or training. It is the result of being on a ketogenic diet for the past eight months. Keto adaptation, the period where the body learns to default to fat for fuel, takes about two months. For an endurance athlete the payoff is real. You go longer without “bonking”, you eat less and less often during long events, and your recovery improves.

A word on VO2 max bragging

People love to brag about VO2 max numbers, often dishonestly. There is one well known doctor entrepreneur in his fifties who claims a VO2 max above 90. That is roughly the equivalent of claiming to have the telomeres of an 18 year old. I think the same person has claimed both, actually.

What this means for you

You do not need a metabolic cart to take advantage of the same principle. Keto adaptation, time restricted eating, and zone 2 cardio work together. Each one teaches the body to be more efficient at using its own stored fat, which is the most abundant fuel any of us carry.

If you want to test the principle yourself, the cheapest version is a blood ketone meter and a glucometer. Track both for a few weeks while you reduce carbohydrate intake gradually. Your numbers will tell you what is happening, regardless of what the scale says.

One promise

Everything I take, make, and recommend gets tested on me first. I have been the guinea pig for every product, every protocol, every diet I have ever written about. I challenge other “thought leaders” in this field to do the same and make their results public the way I have.

Doc