Higher Carbs possible through exercise and gluconeogenesis?

(Fernando Aramburo) #1

Ok group, below are a few questions I’m trying to figure out with the idea that its possible to increase your carbohydrate intake based on knowledge that there are minimum amounts of glucose stored in muscle and necessary for normal physiological function that the body produces when on a keto diet. Is it possible that we can increase our 20/50 grams per day on hard cardio type workout days by supplying the additional glucose the body would create by ingesting it instead?


  1. What is the minimum amount of glucose needed for normal physiology AND stored/kept in muscle that body creates through gluconeogenisis?

  2. How much glucose is depleted during weight training/cardio aerobically and anaerobically?

  3. How long after depleting your glucose stores do you have before your body makes it on its own?

(Tom Seest) #2

I think that you pretty much have to experiment with this yourself, as there are many variables involved in the equation.

As an example, I’ve ridden 60 miles on my bicycle after fasting for 60 hours, while continuing the fast, and I was fine.

I’ve also ridden 310 miles during a 21 day fast with minimal protein, and been fine.

But, I’ve been adapted for 2 years, carry extra fat as an energy source, etc.

(ianrobo) #3

Good questions and something I am doing now as a check as close to Xmas and loosening my policy for a bit.

I saw a piece by Phinney I think it was who said up to 100g of carbs was fine for an athlete at moderate intensity. So really does depend as Tom says on you personally. For example remeber your glycogen stores will get filled up as well taking the pressure off.

(Gabor Erdosi) #4
  1. Muscle and liver glycogen is not interchangeable. The latter can be almost completely depleted, while the former is always replenished. Although it’s traditionally called gluconeogenesis, lactate recycling can be considered a somewhat separate process. It even has a distinct name: Cori-cycle. Lactic acid from tissues running anaerobic fermentation is sent to the liver for recycling to glucose, therefore it is not strictly new (neo-) glucose.
  2. It’s difficult to say without measuring. There are some studies that did, but context matters a lot. In general, fat adapted athletes use more aerobic fat oxidation compared to carb loaded ones.
  3. In a few hours muscle glycogen is fully repleted, regardless of diet. See attached image from a Volek study.

(Fernando Aramburo) #5

Tom, I’ve been adapted for about 18 months. Dont have an issue going with simply 50 grams or less per day (gross; not net) but was looking at how I could add additional veggies and other such carbs without getting kicked out of ketosis.

(Fernando Aramburo) #6

@ianrobo , do you have a link to the piece to maybe get a better understanding of the conditions/loading/etc of the study done? Looks like exactly what I am looking for!

@erdoke, do you think that the glycogen being repleted regardless of diet means that dietary glucose would not be used for the glycogen repletion or if taken at the appropriate time would stop any recygling/gluconeogenisis? The point would be to attempt to increase my carbs without being kicked out of ketosis.

(ianrobo) #7

sorry @faramburo it was just something I cam across so think it was a Youtube lecture of his.

I understand what @erdoke is saying but I have been way about 50g a day these past 3/4 days and still in ketosis. As people said it is different for us all and have to find your own level by N=1 experiments.

(Gabor Erdosi) #8

I don’t know what goals you have with ketosis. Carbs can be increased and still stay in ketosis, given that you want to be just above 0.3 mmol. That’s certainly possible.

(darlee44) #9

Fat adapted 2 years @tdseest? That is phenomenal!! Congrats :kissing_heart:

(Dave) #10

Hi… I was feeling a little flat doing my workouts and not getting much of a pump and I take a heaped teaspoon of dextrose in my pre-workout drink and it has seemed to fix the problem… You can stay in ketosis, just make sure you take it about 10mins before you start lifting… Not science just my personal experience

(Fernando Aramburo) #11

@DJTaylor Have you measured your ketones after working out to see that you are still in ketosis? If so, how long afterwards and what do you use to measure? Thanks Dave.

(Dave) #12

I must admit I haven’t really been that scientific about it… I think I measured it a good few hours after… I only do the wee strips too… I think you usually go out of ketosis after things like sprinting anyway for a bit as your body looks to get whatever glucose it can find… 1 heaped teaspoon is only about 5 or so grams so its not that much

(ianrobo) #13

I always go out of ketosis after an hard session but that is to be expected ?