High-Intensity on Keto


#1

The man is keto curious, but has certain athletic goals he is concerned he requires carbohydrates in order to perform his best.

I think it’s a poorly disguised cover for wanting to not have to quit 12" subs but I won’t say that out loud.

Since I’m not an athlete, I am only really aware of Noakes for athletic keto information. We watched a good talk he gave regarding Athletics, but the Man’s “complaint” was that it was really focused on endurance over high-intensity needs.

Can anyone help me out with studies and/or (even better) videos discussing this? TYIA


Carbs around training?
(Carl Keller) #2

Thomas Delauer talks about carb backloading and carb recycling in relation to working out, in this video. In the footnotes, he does give reference to a few studies.

Idea Behind Backloading:
The idea is that you use insulin to your advantage by not eating carbs when your body is most able to store them as fat (early in the day) - instead, you eat carbs when your body is most likely to store them as glycogen in the muscles (later in the day, after working out) The post-workout point is important: you use weightlifting later in the day to deplete glycogen stores and increase insulin sensitivity in the muscle cells, but not the fat cells, so when you then start eating carbs, your body preferentially shuttles them into the muscles, not fat cells. The theory is that insulin sensitivity will be increased in your muscle cells, but will remain at a lower sensitivity in your fat cells. As a result, when you start eating carbs, they will instantly be utilized by your muscles, rather than being stored as fat (1,2) Good in theory, but you’re not going to see a huge difference in insulin sensitivity if you’re already carb depleted

*edit, the way I understand it, our body prefers glucose in high intensity activities like sprinting but ketones can fuel us just fine in jogging. Certainly if we empty our glycogen stores, carbing up is necessary to restore that quick energy reserve.


#3

Carl you really are a star thank you


(Carl Keller) #4

My pleasure. :slight_smile:


(Bacon is a many-splendoured thing) #5

Your Man has a point. As I understand it, keto is excellent for endurance work, but explosive performance (sprinting) may require some carbohydrate. Notice, that’s “some carbohydrate.”

I’m not sure this is settled science, because I’ve recently read a couple of papers that suggest that, in fat-adapted athletes, glucose levels return to normal after a certain period on a well-formulated ketogenic diet. On the other hand, however, there does seem to be quite a bit of anecdotal evidence to support the Man. But it’s still not license to eat all the pizzas! :grin:


(Bob M) #6

Here’s one study:

If you search for Phinney or Volek using that web page, you should be able to find more studies. This is their characterization of a Volek study:

This study indicated that endurance athletes could maintain normal muscle glycogen content, utilization and recovery after long-term adaptation to LCHF diets. These metabolic adaptations to LCHF diets may benefit endurance performance. Thus, it has been hypothesized that long-term LCHF diet may enhance performance in ultra-endurance events such as the ultra-marathon and ironman triathlon by supporting a higher fat oxidation rate at higher relative exercise intensity and by having a glycogen sparing effect (Langfort et al., 1996). In these events, the LCHF-adapted athletes may be able to maintain higher relative exercise intensity during most of the distance, while preserving muscle glycogen for sprints at the later stage of competitions. Future studies may evaluate endurance performance in LCHF-adapted athletes using a race-like design, rather than constant workload protocols.


(Bob M) #7

And if you look on the right side of that webpage, there are tons more citations to other keto/low carb studies. Not all of them are for athletes, but a lot of them are.


(Doug) #8

@ctviggen - Bob, good mention, there. Jeff Volek has done/is doing amazing work. I ******* love this stuff. :slightly_smiling_face:

Paul, for maybe 10 seconds or 100 meters (or probably 60 meters for me) we’re using the fastest-access energy of all, knocking phosphate groups off of adenosine triphosphate (ATP) and phosphocreatine (PC) (doing it to PC makes more ATP). We don’t store much, soon have to start making more, and things slow way down.

Then comes the Cori cycle or lactic acid cycle - we’re using glucose anaerobically, getting energy by turning it into lactate, then sending it to the liver to get turned back into glucose and the cycle continues. This goes or 2, maybe 3 minutes.

Finally we get to oxidizing carbs, fats, or even proteins - this is what we can do for a long time. Obviously heavily dependent on oxygen availability and transport. Carbs have a built-in advantage in that they come with a good bit of oxygen included; we don’t have to supply as much. (Glucose is over half Oxygen by weight.) Fatty acids are almost all just carbon and hydrogen, requiring a lot more supplied oxygen. Most fatty acid molecules will produce more total energy than a molecule of glucose, but glucose is a more efficient fule because of the oxygen that comes with it.

I’ve read that all other things being equal, there’s about a 20% advantage to using carbs over fats, there. Training can increase the number of mitochondria in the cells, which is advantageous then, regardless of the fuel used. There is some overlap of these 3 phases of energy production - of course we’re also operating aerobically, to an extent, all along.

One thing that may be tilting things in favor of burning fat is that a keto diet also increases the number of cell mitochondria, at least in your old buddies - rats.


(Bacon is a many-splendoured thing) #9

Ah, that must be why VO2 goes up, then.

Rats! Gotta love 'em. :heart:


#10

Thats quite accurate to my own findings ive had when comparing the times ive been on either carbs or keto, when lifting. Weights and reps is pretty much 80-85% from what i can lift with carbs. On keto low intensity stuff like treadmill feels like i could do forever and when on carbs u start to feel the tiredness much earlier.

I wonder if it matters what foods exactly is best for the carb backloading, cause i remember reading somewhere that fructose from like pre-workout fruit would go straight to liver and not in muscles.


(Carl Keller) #11

I honestly don’t know but here’s what Dr. Jockers says:

https://drjockers.com/carb-backloading-the-fat-burning-benefits-of-this-eating-pattern/