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Glycogen is maintained and replenished during ketosis.

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  • #16
    I saw an interview on TV with that Dr. Phinney who just wrote the latest low-carb books. He is normal weight (looked rather thin) and says he's been in ketosis for 6 years--continually with no carb cycling. He's also a runner. He claims that ketosis is a positive state for the body, and he has never felt better or been healthier.

    I don't measure ketosis, but I typically eat about 20g of carbs a day because I'm extremely carb sensitive, and this is the best way to manage my weight. I'm 71 and also have never been healthier in my life. It may be an individual thing--i.e., the fact that I am so carb sensitive may mean that my body works best on limited carbs.

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    • #17
      Originally posted by j3nn View Post
      Is perpetual gluconeogenesis very stressful to the body (and mind) in the long-term?
      When blood sugar gets low glucagon is produced. This promotes gluconeogenesis and happens before blood sugar drops low enough to trigger increased cortisol. Thats basically biochem text book stuff, but there is a whole article on it here :


      The Ketogenic Diet for Health: Ketogenic Diets, Cortisol, and Stress: Part I — Gluconeogenesis.


      I would think that if your activity level was vastly outside the parameters of your ability to produce glucose via gluconeogenesis (like HIT 2x/day or something) then that could be stressful, but lets face it....a program like that is not likely to be healthful anyway and your probably willing to sacrifice a bit of health for athletic ability. But I'm just speculating.

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      • #18
        Read Vilhjalmur Stefansson's book The Fat of the Land. Very little discussion of ketosis or gluconeogenesis, but lots of discussion and examples of the healthfulness of a diet lacking anything except lean meat and fat. Not just healthy enough but actually superior health compared to mixed diets. It's really very fascinating.
        Female, 5'3", 50, Max squat: 202.5lbs. Max deadlift: 225 x 3.

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        • #19
          Originally posted by The Scientist View Post
          I was doing some reading and stumbled across this rather old, but very interesting paper. The idea is simple: they put rats on a ketogenic diet (surprisingly, real meat and vegetables) and had some train (running) and some not. Liver and muscle glycogen were examined before and after exercise (running).
          The study was made on rats, what relevance do you think these results will have for human athletes?

          Originally posted by The Scientist View Post
          Clearly glycogen stores can be replenished during ketosis after exercise, and having been on an exercise regimen makes it happen for efficiently.
          If replenishing glycogen stores with eating fat was superior or equal to carbs wouldn’t some of the top athletes have used this to win over athletes loading on carbs? To get top results in many disciplines an athlete need to be “supercompensated” and I have still never heard that someone got supercompensated on fat and proteins only...
          "All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."

          - Schopenhauer

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          • #20
            different people will have different abilities when it comes to gluconeogenesis. some people's ability to produce glucose will be more or less robust than others. everyone will be able to produce enough glucose to refill liver glycogen - or you'd be dead. but the idea that your muscle glycogen stores will remain full on a ketogenic diet is fantasy.

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            • #21
              Originally posted by Annlee View Post
              Not true - the Bison Peoples (Lakota, Shoshone, Cheyenne, Blackfeet, etc.) ate very little in the way of fruits and vegetables. They ate bison meat and fat, with occasional other meats like antelope. Their history and diet is well documented by the early plains explorers from the US and Canada.
              During the winter months, yes. In the summer months, they ate various berries, fruits, tubers, and other plant foods, and their travels followed the availability of prized wild foods. The traditional diet varied seasonally (and still does--there are still Aboriginal people who eat many traditional foods). In the winter months, yes, food consisted more of meat and fat with some conserved berries, but even then, there are methods that were used to store some foods in the cold ground over winter. Their diet was certainly lower in carbohydrate than the common SAD diet, but it was not zero carb or even as low carb as northern groups such as the Inuit. The bison were definitely a core food, but they were not the only food by far.

              It's actually sort of ridiculous to only base one's ideas of Aboriginal foods on the records of the fur traders and explorers when those peoples are still around and still have traditional knowledge intact around their cultural foodways. A lot of work has been done by members of those communities to document their own histories, which have tended to be displaced in the North American cultural narrative by the stories told about them by outsider explorers and traders (which are not always wrong but are also not insider stories of a people).

              There's an ongoing tendency in paleo/primal communities to neglect the abundance of information out there from actual Indigenous peoples on their own foodways, and I think we make a huge mistake in doing so because there's a lot to be learned by looking at the real dietary practices of the people we claim to want to emulate, and mythologizing them as people of some misty past misses a lot of opportunity for learning.
              “If I didn't define myself for myself, I would be crunched into other people's fantasies for me and eaten alive.” --Audre Lorde

              Owly's Journal

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              • #22
                Originally posted by jakey View Post
                everyone will be able to produce enough glucose to refill liver glycogen - or you'd be dead. but the idea that your muscle glycogen stores will remain full on a ketogenic diet is fantasy.
                That's what I also thought, but some people think that it still can be done, so what evidence can be brought on the table except from rodent studies with limited relevance for humans?
                "All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."

                - Schopenhauer

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                • #23
                  Originally posted by Gorbag View Post
                  That's what I also thought, but some people think that it still can be done, so what evidence can be brought on the table except from rodent studies with limited relevance for humans?
                  Yeah, I actually think there is some data out there on this. But, I'm not sure what my source is as this is from memory (may be from Phinney's book). Anyhow, on a long term ketogenic diet I believe that your muscle glycogen stores are approximately half of someone who may be carbing up. The difference then becomes what substrate the body utilizes at what intensities. Change in your bodies use of energy sources such as reported here :

                  The interplay of exercise and ketosis

                  I don't know of any large studies done to this effect, rather haven't looked very hard for them, but Peter Attai's N=1 is an interesting post.

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                  • #24
                    This study is positive proof that it royally sucks to be a lab rat. This study still doesn't change the fact that ultra low carb diets are not the best choice for endurance athletes and rat studies make a piss poor basis to make dietary changes for anything other than the poor rats that volunteer for the next pointless lab experiment.
                    http://www.facebook.com/daemonized

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                    • #25
                      But there have been human lab rats as well. The decades and decades of children raised on a ketogenic diet to control epilepsy are examples. They have competed in school athletics and grown up just fine with no adverse effects on their health. Of course, once they hit puberty, they have been allowed to drop ketosis in favor of pizza and soda but, by then, a great many of them were completely cured.

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                      • #26
                        Originally posted by Neckhammer View Post
                        Yeah, I actually think there is some data out there on this. But, I'm not sure what my source is as this is from memory (may be from Phinney's book). Anyhow, on a long term ketogenic diet I believe that your muscle glycogen stores are approximately half of someone who may be carbing up.
                        It also depends of what "carbing up" means here, and half of glycogen baseline will not be enough for top performance. Personally I know that my performance in sprint or weightlifting will be much better due to a higher internal pressure in the muscles due to glycogen and water. To get this, the muscles must first be somehow depleted and thereafter supercompensated and supersaturated with carbs, and proteins and/or fat cannot achieve this level of glycogen storage to my knowledge.

                        Originally posted by Neckhammer View Post
                        I don't know of any large studies done to this effect, rather haven't looked very hard for them, but Peter Attai's N=1 is an interesting post.
                        The problem with ketosis to my experience is not low intensity endurance kind training, but when you get anaerobic work such as intervalls, sprints and weightlifting...
                        Originally posted by Peter Attia View Post
                        I think the perfect athletic event for ketosis would be an Ironman triathlon or marathon running or ultramarathoning. Anyone who needs to be *just* under threshold for really long periods of time will capture most of the benefits of ketosis. But in my experience (and I believe Steve’s), do you have to give up some sprint capacity, so I would not recommend it even for the guy trying to win the Tour de France, as you still need to sprint when the pack moves.

                        Originally posted by Peter Attia View Post
                        Greg, if my goal were to win a gold medal I would probably have to change my diet. If you think about it (I’ll be doing an entire post on this), carbohydrates are in some ways like a performance enhancing drug — help with certain aspects of performance, but have some chronic harm associated with use.
                        "All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."

                        - Schopenhauer

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                        • #27
                          Originally posted by Daemonized View Post
                          This study is positive proof that it royally sucks to be a lab rat. This study still doesn't change the fact that ultra low carb diets are not the best choice for endurance athletes and rat studies make a piss poor basis to make dietary changes for anything other than the poor rats that volunteer for the next pointless lab experiment.
                          +1.
                          F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.

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                          • #28
                            Originally posted by Daemonized View Post
                            This study is positive proof that it royally sucks to be a lab rat. This study still doesn't change the fact that ultra low carb diets are not the best choice for endurance athletes and rat studies make a piss poor basis to make dietary changes for anything other than the poor rats that volunteer for the next pointless lab experiment.
                            Agreed. I'm not saying this study is bad science, but a lot of bad science has been done using rats, mice, rabbits, chickens - animals with totally different physiology than humans'- claiming that the effects these animals exhibited apply to us as well. The human lab rats Paleobird mentioned are much more relevant than a study on rodents.

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                            • #29
                              Originally posted by Paleobird View Post
                              But there have been human lab rats as well. The decades and decades of children raised on a ketogenic diet to control epilepsy are examples. They have competed in school athletics and grown up just fine with no adverse effects on their health. Of course, once they hit puberty, they have been allowed to drop ketosis in favor of pizza and soda but, by then, a great many of them were completely cured.
                              Evidence of what? That a ketogenic diet is just as good for glycogen replenishment related to athletic performance???
                              "All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."

                              - Schopenhauer

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                              • #30
                                Originally posted by Gorbag View Post
                                Evidence of what? That a ketogenic diet is just as good for glycogen replenishment related to athletic performance???
                                Obviously they were kids, not competitive bodybuilders. But what their example show is that it is very possible to lead a perfectly normal, physically active life as a growing youngster on a ketogenic diet without any adverse effects to health. Kids burn though a lot of glycogen too.

                                The studies on adult epileptics have not been going on for as many decades so there is not such a huge body of evidence yet but the exact same thing is happening so far in the studies done at Johns Hopkins.

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