Ketones surging after exercise

(Debra Moore) #1

Hello, I’m a veteran keto follower who went off the wagon and just recently got back on. Anyhow, my usual ketone levels (measured by blood meter) is between .5 and 1.5. This morning, before I rode my Peloton bike for one hour, the ketones were .8.

Now, some 5 hours or so after my bike ride, my ketones are 3.0. They’ve NEVER been that high. I happen to have two different blood meters (I lost one of them, so I bought a new one, then I found the first one, so now I have two). They measure the same.

Is this unusual or cause for concern? After my first reading that seemed high this afternoon - it was 2.8 - I ate some low carb cookies (about 15 grams of carbs for the four cookies I ate) and had a quarter cup of macadamia nuts. The ketones only increased after these snacks. I measure my carbs online, and I’m at around 50 total carbs for the day, around 30 net carbs.

I’m wondering if the intense exercise is causing this? I kind of hammered it on the bike ride for the hour, at least for me, I did. I plan on doing my bike 3x a week, alternating with my Pilates workouts 3 x a week.

Anyhow, any advice would be welcome and thanks in advance!

(Bacon enough and time) #2

The usual rang of nutritional ketosis, as defined by Phinney and Volek, anyway, is 0.5 to 3.0 or so. Fasting ketone levels (starvation ketosis) range somewhat higher than that. Ketoacidosis is not a concern unless serum β-hydroxybutyrate rises above 10.0, and even then, symptoms don’t start until 20.0 or so.

I suppose it can’t hurt to post this graph once again:

(Marika) #3

@DebraMoore I’m at 2.0~3.0 on a daily basis and feel fine, 4.0~7.0 after exercise, especially if done when fasted. However, I seem to have been overdoing it with the workouts. When my ketones are above 6.0 (and my glucose accordingly at ~50 or so) - I feel “see-through”, dizzy and have problems eating because of nausa. So I’m trying to tone that down currently… Still, you’re not the only one and your ketones are not THAT hight I would say :slight_smile:

(9f9119df3f0e3bfb900a) #4

I’ve heard Dom D’Agostino phd talk about athletes registering higher ketones post-exercise. Wish I could tell you more about it, but he is too technical for me to hang on to the info.

Edit: removing show I listened to, which was about ketogenic diet and cancer, adding one on more topic.

I didn’t listen to this one, but I think you might find it more of interest than the show I watched.

(Greta) #5

Not sure why my post about Dom D’Agostino didn’t connect to my profile. I logged out and logged back in to fix it.

(Bacon enough and time) #6

You were in anonymous mode. Logging back in fixed it.

(Greta) #7

Thanks. I must have hit something while punching around on my phone.

(Bob M) #8

I wonder if it could also be dehydration? I read this book, which is more about electrolytes:

He says to drink to thirst and there is no reason to drink to excess. (But I’d really like to see this updated for people on keto, who seem to have unique electrolyte issues.)

But I wonder if it’s possible an increase in ketones could be due to a slight decrease in blood volume or whatever happens when you’re exercising? The body tightly controls what’s happening to the blood, though, so I’m not sure.

(Bacon enough and time) #9

I’m sure there’s some room for variation, no matter how tightly controlled. An animal that couldn’t tolerate a certain amount of dehydration would quickly die out, no?

(Michael) #10

Did you test an extra 50 g of protein on your ketone level by chance?

(Bob M) #11

I’ll have to see if I can find that book. I can’t remember what happens to the salt level in your blood, for instance, when exercising (he was mainly looking at running a marathon). I know that the people who die are the ones who are very slow runners (aka, me) but that drink and drink and drink…because that’s what they were told to do. That causes their electrolytes in the blood to go down (because even Gatorade and the like don’t have enough to actually replace electrolytes, you need a saline solution given with a ton of salt in it), but I can’t remember what happens if you’re not drinking. I think your electrolytes go up in the blood. But I can’t remember.

I was wondering if the same happened for ketones.

Could you limit this by eating protein? Not sure. And it might depend on when you eat it.

(Bacon enough and time) #12

Dr. Noakes was the researcher who first promoted the idea that runners needed to hydrate, and it was the sport drink manufacturers who took that advice and over-promoted it. To think that runners would really need a cup of water or a sport drink every mile or so is just plain absurd. Our ancestors didn’t have water tables along their hunting routes as they were chasing down prey, after all.

To his credit, Dr. Noakes was also the first to warn against the dangers of over-hydration. And unlike most researchers, he has never been afraid to admit that he was wrong.

As for the electrolyte balance when we sweat, perspiration does contain salt, after all, so there may not be much of a problem with electrolyte balance during physical activity. The body seems to be designed to handle a wide range of conditions. Although it is possible to die from thirst, at some point, just as it is possible to die from too much water.

I’m not sure what your reason is for mentioning this. If the concentration of ketones rises during physical exertion, is that a bad thing? And how high is the concentration likely to rise anyway, in someone who needs the energy in order to fuel his or her physical exertion?

Our ancestors most likely did a lot of their exercising while fasting, since there’s no need to go out and bring down a mammoth while you’re still working on the carcase of the last one. Well, that’s more likely true for the men, since women probably spent a lot of their time taking care of the kids and doing other chores; in other words, expending energy at a more constant, continuous rate.

(Bob M) #13

I’ve tested it a bunch of times, and, for me doing the exercises I was doing, blood sugar goes up and ketones go down. (That’s to the extent these are testable, since CGMs have a nice curve, but pin-prick meters suck.)

But these people are having their ketones go up, not down. I assume that’s because they are doing aerobics over a longer time period, whereas I was doing body weight training and/or HIIT.

But why would the body choose ketones and not blood sugar? How do ketones replace glycogen? Why do some exercises cause blood sugar rise, and others don’t?

I perceive ketones to be used as an “emergency” fuel: burn through blood sugar first, and then ketones have to increase. But is the increase they are seeing really that high? Or is there also some dehydration setting in that makes them look higher than they really are? (If you’re getting 7+, that’s high.)

Do different exercises affect different types of muscle fibers, such that the body partitions different fuels? How does my body “know” I’m doing body weight training instead of aerobics, thus causing blood sugar to rise? Or do different muscle fibers use different fuel.

I could go on.

(Bacon enough and time) #14

I just thought of something: the skeletal muscles prefer fatty acids over ketones and glucose. It takes a need for explosive power, or an elevated insulin level, to make glucose the priority. Or so I understand. But then, we know that the heart muscle does really well on ketones, especially when there is some arterial blockage, since ketones require less oxygen to metabolise (since they are already partially-metabolised fatty acids).

So perhaps the deciding factor is not how much exertion the skeletal muscles are engaged in, but rather the type of exertion, combined with the needs of the heart. And I’m sure the brain’s needs figures in there somewhere, as well. And before anyone takes this as settled science, it’s not. It’s pure speculation on my part.

My understanding is that glucose takes priority primarily when there is a need to clear it from the blood. However, if we are exercising in a way that requires explosive power, then the liver will release glucose from its stored glycogen to fuel it.

But then the question becomes how the fast-twitch muscles signal their need for glucose? Presumably, they are starting by using some sort of glycogen store of their own, before the liver becomes aware to start sharing its glycogen/glucose, but while they are using their own sugar, they need to signal the liver to get busy, right?

That is a very interesting question. I wonder if anyone has any answers.

Well, the first part of the question is clearly yes. But the second half may not have been investigated, yet. On the other hand, we know that fast-twitch muscles provide explosive power and (presumably) require glucose for that, since the glycolytic reaction is (or so I understand) faster than fatty-acid metabolism. (Does the body keep a store of ATP handy anywhere for emergencies, or does it only make it as needed?)

There have to be hormones at work to signal some of this. And in addition, the metabolic reactions involved take different pathways, depending on the availability (or lack) of such substrates as acetyl coA, lactate, and the like. I’ve seen flow charts of these reactions, and they are quite complicated. Can’t say that I really understand any of 'em.

(Alec) #15

This balance the fuel source is an interesting arena. We have the following fuel sources, with my suggested scale of usage on keto (highest first):

  1. Fatty acids
  2. Ketones
  3. Blood sugar created by the liver: I know very little about the rate that this happens
  4. Blood sugar ingested: on keto this doesn’t last long if you are exercising (I burn 600 calories in an hour on the run, with the day’s 20g of carbs being 80 calories!)
  5. Protein, either ingested or current body structure (burning the furniture)

If the body is being challenged with a decent hour of cycling, most/all of the carbs will have been used, so fat burning and ketones will be what’s left. I am not at all surprised by a ketone level of 3. Sounds good to me. :+1: