Hi Lex,
Even if fatty acids are less mobilized, there are still some that get mobilized and enough so that ketones also rise significantly.
References
'What's the best fuel for muscles?' Jeff Everson- interview With Greg Ellis- Weider's Muscle and Fitness mag, May, year (?)
'Body Fat' by Vincent P Dole, Scientific American.
'Dietary hyperphagia in Rats: Role of Fat, Carbohydrate, and Energy Content. Israel Ramirez and mark L Friedman, Physiology & Behavior, June 1990.
'Regulation of Hepatic Fatty Acids Oxidation and Ketone Boldy Production' J D McGarry and D W Foster, Ann. Rev. Biochem 1980 49:395-420.
From The Bear, with 47 yrs of experience on an all-meat diet...
"I am searching for my collection of metabolic studies, but so far it has eluded me. Two studies relate to energy source and exercise, both were done with lab rats. One shows by muscle biopsy/analysis that the glycogen in muscle tissue does not vary with exercise, whether anaerobic or anaerobic. The other shows massive gains in endurance over a sufficiently long period of adaptation to a zero carb diet. This study is one of the very few to use a true zero carb diet against a normal rat-chow control in a test."
"glycogen is never used as a fuel for exercise- the muscles burn only fat). Glycogen is stored around the body and is used as a fast resource when blood sugar drops- since glucose is not consumed by skeletal muscles it remains in the tissues."
"Carbs before a workout will reduce your energy- although some people will have a kind of 'boost' from the sudden insulin rush. The muscles run on fat, and once the body starts to store the glucose as fat, it interferes with energy and strength. Carbs weaken you by initiating fat storage activity just when your muscles need the fat for power."
"I am carb free, I exercise anaerobically by lifting weights. I NEVER get sore muscles the next day- or the day after unless I am forcing a severe weight overload, which causes more severe micro damage to the muscles, and some second-day soreness. So there's the 'practical' proof that glycogen does not deplete with exercise."
"ALL muscle fibres use the same fuel, fast and slow both burn only fat. NO muscle fibre uses carbs. (Once more) glycogen is not used to do work, only ATP-ADP reduction is used, that is rebuilt by fat. Glycogen does not produce ATP. Glycogen is not depleted with exercise- this is proven and is in the literature. Opinions to the contrary are just repeating fairy tales from the past. Carb intake reduces strength/speed, and likewise reduces endurance/distance."
"A careful read of the article on
http://www.nutritionandmetabolism.com/content/1/1/2 reveals that contrary to the assertion, 'glycogen depletion' was not taken as a measure, only oxygen consumption. Glycogen STORAGE was reduced during the first TWO WEEKS and thereafter remained stable- not surprising since much of the reason for holding glycogen in the muscle tissue is the need to quickly remove glucose from circulation- it is much faster to convert glucose into glycogen than for the adipose tissues to convert it to bodyfat. Glycogen is not used up or 'depleted' during exercise, it functions only as quick, emergency source of blood glucose- and that is all. After withdrawal of carbs from the diet, the massive glycogen storage in the liver is also vastly reduced, thus facilitating blood flow through the hepatic vein from the lower body and preventing the 'stitch in the side' so commonly experienced during carb-loaded athletics."
"ATP is not CREATED by fat, the ADP produced from ATP during work by the muscles is RECYCLED in the cell by a mechanism FUELED by the complex: n,acetyl carnitine:fatty acid."
"Actually insulin is NOT anabolic to somatic working muscles, striped and short-striped- only to the involuntary, smooth kind found in the intestines and arteries, where the effect is undesirable."
"Carbs of any kind, glucose OR glycogen are NOT used to do work by the muscles. Until you are free of carb intake long enough top fully keto-adapt, which takes from 3 to 6 weeks, you will experience a feeling of lower energy. ANY carb intake, no matter how brief, will derail the keto-adaptation process. Your 'keto-diet' is complete nonsense."
"Insulin is not anabolic to the skeletal muscles, it will cause an apparent increase in size due to an increase in intramuscular glycogen storage and the associated water retention, as well as fat (marbling) but the muscle cells do not show any increase in the size or number of active fibre bundles as is associated with genuine anabolics, like testosterone and its derivatives."
"Yes indeed, high carbs are absolutely great at building intramuscular fat,looks good, big and meaty, but carbs strongly limit any addition of larger muscle fibres (real muscle size)"
"Muscle cells 'run' on ATP-ADP conversion. ADP-ATP re-conversion is done with FFA's. It makes no difference whether the exercise is anaerobic or aerobic, the muscles still work the same way. This is like a car- whether in first gear or in overdrive, it still uses the same fuel. Glucose is not a fuel. Glycogen is not a fuel. Neither can be used to translate ADP back into ATP until converted into FFA first. Mitochondria mediate ADP to ATP conversion which is why there are two 'types' (fast and slow twitch) of muscle cells, fibre bundles with more mitochondria have a different response to the two types of work, aerobic and anaerobic. The mix of types in a given muscle can be altered to some extent by training."