Back on KETO -running and fasting

[CFLBob]

Clearly enough to keep you doing it week after week. You mentioned glycogen in muscles - isn’t that usually burnt up in ketosis after a while anyhow? Thank you so much for your advice here, interested to try this

Your glycogen is continually replaced. This is where the term gluconeogenesis comes in. Your liver (pretty sure it’s there and not in the muscles themselves…) creates the glycogen and your blood circulation takes it to the muscles - it’s why carbohydrates are not “essential” nutrients; that is, carbs are not something you need to eat because your body can make as much as it needs. That said, I’ve seen people say that having some carbs before a workout helped them. It’s one of the reasons I was asking. FWIW on my (not-quite) 70 mile ride I wasn’t hungry for a minute and had no sensation of “bonking.” Dinner was just a regular size dinner with no “I’m so hungry I could eat a walrus” feelings at all. I don’t think carbs would have improved anything.

As for why do I do a long fast weekly, I suppose that it’s mostly because I like to remind myself that eating is optional. Sure, we have to eat, it’s just that some people put so much emphasis on it that they freak out if they can’t get something every two hours like clockwork.

I find I don’t really get hungry, I just get a craving for something. Two weeks ago, I grabbed a fatty hunk of hog jowl bacon and had it in my mouth before I remembered it was my fasting day. I wasn’t even craving the taste, it was just the time of day when I typically grab one. So it became a non-fasting day.

Hope that helps. Any questions? Just ask.

[PaulL]

Your glycogen is continually replaced. This is where the term gluconeogenesis comes in. Your liver (pretty sure it’s there and not in the muscles themselves…) creates the glycogen and your blood circulation takes it to the muscles - it’s why carbohydrates are not “essential” nutrients; that is, carbs are not something you need to eat because your body can make as much as it needs.

As you say, the liver makes glycogen as a reserve for the skeletal muscles, in case we suddenly need to punch a cave bear or something. If we eat too much glucose (also known as carbohydrate), the muscles can make their own glycogen, but the glycogen is trapped in each muscle cell; it cannot be shared with other muscle cells. That’s one of the reasons the liver makes glucose/glycogen.

And yes, the body is designed not to have to depend on carbohydrate foods. It would appear we evolved this way because the race at mostly meat; carbohydrates back a couple of million years ago were very fibrous and usually available only at certain times of the year, whereas hunting was a year-round activity.

The cells that absolutely must have glucose are our red blood cells, because they lack mitochondria and therefore cannot metabolise fatty acids or ketones. The brain appears to need some minimal amount of glucose, as well, but the amount is in dispute. There are a few other cells in the body that also need glucose, but which they are escapes me at the moment.

Skeletal muscles prefer to metabolise fatty acids, even more than ketones. They need glucose only for explosive power; for endurance they do better on fats.

[CFLBob]

I was hoping you’d drop by and improve that post, @PaulL.

Some of these things I haven’t reread in almost 10 years, and I get unsure of the details.

[Saphire]

My experience with this over my lifetime has been mixed.

In my last year of college I decided to try to walk on to the swim team (no idea what I was thinking!) I had swum in high school (very mediocrely) but not in college although was relatively active, learned to play squash, and had been swimming a half mile or so a few times a week at my own pace. At the time I needed to lose 10-20 lbs to be at my ideal weight but I was still relatively lean.

For the month or so that I was on the team, where I was pushing my speed to try to catch the swimming recruits, swimming fast 200 meters numerous times over the two hour or whatever it was workout, I suddenly found that I could eat whatever I wanted and was still losing weight. I think the key was that I was going for longer and faster, it was essentially a HIIT workout for me, since I was trying to keep up with people who were much faster (needless to say I was cut!) I was on a college meal plan so really ate whatever I wanted and my favorite food is carbs! After I was cut, I continued to swim at my own pace a few times a week and to play squash but I regained the weight I had lost while on the team

During my 20s I was able to keep my weight, in check while eating pasta and going out while working long hours by walking home 2.5 miles most evenings. In my early 30s I started biking with a club. I found that it helped control my weight but it did not help me lose weight and I was riding about 30 miles each day on the weekend and 10-15 miles twice a week during the week. While the pace was fast, compartively it probably was not as fast as my swimming pace.

I recently started exercising again (age 55+) for the last 1.5 years I have been playing tennis 2-3X a week for fun. I try to exercise in the evenings because I find I am less stiff than in the morning. I did find that it seems to aid a little in weight loss, especially because I try to stop eating by 5. However, I recently added a little indoor biking and some mild circuit training and I seem to be stuck in terms of weight. I keep hoping it is because I am building muscle but it may be too soon.

A few months ago I tried playing tennis in the morning on hour 40 of a fast and found I lacked energy but it may simply have been a one time thing, plus I really do not play as well in the morning no matter what I eat

[ctviggen]

And yes, the body is designed not to have to depend on carbohydrate foods. It would appear we evolved this way because the race at mostly meat; carbohydrates back a couple of million years ago were very fibrous and usually available only at certain times of the year, whereas hunting was a year-round activity.

One thing I should add to my review of the book Burn is the following part that has cognitive dissonance. He shows a table where they took tribes at different distances from the equator and what they ate. The farther you got from the equator, the more meat you ate. His conclusion, of course, was that we should all eat carbs.

But I look at that and say, well if you have genetics from a northern clime, maybe you should eat more meat and fewer carbs? I am 99.8% European and 7X % Eastern European. Maybe I would be better off eating more meat than, say, someone with African heritage? (Yes, I know about the Maasa, but I’m thinking generally here.)

[kib1]

Isn’t that awful? Lol. When you start a confident scientific explanation and suddenly realize it’s not actually in there any more. “Well yes, you see, glycation produces … um, well, somethin, that … er …”

I still trust the science I learned, but sometimes it’s like a fancy exoskeleton with nothing inside.

[CFLBob]

I still trust the science I learned, but sometimes it’s like a fancy exoskeleton with nothing inside.

Excellent!

And then there are things that I think I know that aren’t so. In another thread on the forums, I talked about lactic acid buildup in our muscles from going anaerobic too long and someone said that idea has been disproven. Or something close to that.