by T.J. Murphy
As I mentioned in a story published last year in Outside Magazine, I first heard the word ‘ketone’ while learning about paleo guru (and former big name in triathlon), Mark Sisson. Later, I would listen to a discussion between another bestselling author on paleo, Robb Wolf, and an extremely accomplished scientist and author himself, Dr. Ken Ford of the IHMC. Ford—who has expertise in computer science, artificial intelligence, robotics and biochemistry—is surely one of the modern-day pioneering thinkers when it comes to what is called nutritional ketosis. His research institute, operating with funding from the likes of DARPA and the U.S. Navy, has been studying the potential of the ketogenic diet as a tool to help war fighters in extreme situations. (I wrote about some of this in a more recent story for Outside, published last October.)
A super-simplified description of the ketogenic diet: It’s a diet that is low in carbohydrate, requires moderate protein and typically is high in fat. You downshift carb intake from 200+ grams per day to 50 grams or less (depending on the individual) and meet your caloric needs through higher intake of fat, ideally good fats from sources like olive oil, avocado, cold-water fish, nuts, etc.
Although you have to account for individual variation in that we are not all wired the same and some may respond differently than others, adhering to this basic macronutrient ratio between carbs and protein (very low carbs, moderate protein but not too much protein) you will eventually produce enough ketone bodies that you will be in nutritional ketosis. Nutritional ketosis is similar to the brand of ketosis your body jumpstarts if you were lost in the winter wilderness and unable to catch a rabbit or squirrel. Aka starving. The metabolism shifts to a ketone metabolism and your brain and muscles begin to burn ketones and stored fat to survive. That’s right: the brain burns glucose, but it also burns ketones, and according to Ford, the brain will burn the ketones preferentially.
One of the areas that Ford is especially articulate with is how nutritional ketosis has a wide-range of ‘resiliency’ benefits throughout the body via epigenetic signaling. From tuned up mitochondria to a protein-sparing effect to enhanced cognition, ketosis seems to give a human being a super-efficient fat-burning metabolism and all sorts of other benefits that allow a human being to survive for long periods without food. In effect, the low-carb/mod-protein/high-fat diet mimics what routine bouts of famine did for our cavemen ancestors as they struggled through tough times.
A surprise in the reporting was the growing embrace of the ketogenic diet by certain individuals in the endurance community. This past summer, at the Dave Scott Experience camp in Kona, campers, including me, listened to Dave talk about the mechanics of the ketogenic diet and the benefits for triathletes both in terms of performance and health/longevity.
Also, Dr. Tim Noakes of South Africa, the ultra-running medical-doctor/sports-
scientist who has lectured at the sports science conferences held in conjunction with the Hawaii Ironman (and spent time in the medical tent). Noakes is author of several books, including the five-pound-tome “The Lore of Running.” I won’t go into Noakes’ full story here (and I encourage you to check out his stump speech included here), but he has become a fierce advocate of the low-carb diet as path toward fighting the obesity epidemic plaguing the planet Earth.
So in a series that I’ll include within the Jet Stream column here on LAVA, I’m going to spend some time doing a little further investigation into the ketogenic diet—what is it, what it’s like and what it does or doesn’t do.
For me, I’m personally interested in the health/longevity benefits of nutritional ketosis, not just the performance enhancements. One area that Ken Ford is investigating is the value of nutritional ketosis in protecting an individual—40s, 50s and beyond—from the lean muscle mass loss that can accompany the aging process. Lifting weights is one way to counter “sarcopenia,” but the signaling properties of nutritional ketosis may be another significant weapon.
But there is certainly a performance aspect that some endurance athletes are exploring in regards to low-carb. Being in ketosis means that your body has made the burning of fat especially efficient. This can have a glycogen-sparing effect for the endurance athlete, one that may free (for example) and Ironman competitor from the need to take in carbs every mile or two to prevent bonking.
Ultra runner Zach Bitter was “fat-adapted” from sustaining a low-carb diet for more than six months, as the saying goes, and was part of a study conducted by Ohio State’s Jeff Volek, PhD. As Bitter learned from the collected data, he was burning more than 1.5 grams of fat per minute when running at a low intensity. And even as he cranked up the pace, he continued to burn a surprising amount of fat. As he reported on his blog:
“My fat metabolism peaked at 1.57 grams/minute. At this point in the test, my VO2 uptake was at 49.4. By dividing this number by my eventual VO2 Max of 66.1, I can calculate at what intensity I burn the most fat: 74.4%. At that intensity, I was burning 98% fat 2% carbohydrate (1.57 fat grams/minute and .07 carb grams/minute). To put this into perspective, 65% of my VO2 Max had me running approximately a 7:15 per mile. Even when I increase my speed to around 7:00 per mile, I was still burning nearly all fat! Of course, as the intensity moves up, these numbers begin to shift a bit, but you would be surprised at how efficient at fat burning one can be, even at increased intensities.”
Data points collected during one of Bitter’s running tests is below. The full post is here.
So in this series, I’ll talk to and report on other observations on the ketogenic diet, triathlon and endurance sports in general. Also looking to supplement the series with some podcast discussions with folks (and others) mentioned above.