Nutrition & Metabolism | Full text | Ketogenic diets and physical performance
The above should take you to an html version, and there is a PDF link from that page.
For those with tl;dr syndrome, key quote is here:
" Therapeutic use of ketogenic diets should not require constraint of most forms of physical labor or recreational activity, with the one caveat that anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics. "
Last edited by dnj1965; 06-30-2013 at 05:22 PM. Reason: added quote to those not inclinded to follow the link...
SW = 280, PSW = 245, CW = 228, UGW = 194
6'2" Male, Late 40's
Last edited by Gorbag; 07-01-2013 at 08:29 AM.
1) Measuring athletic performance using elite-level subjects running ultras is idiotic in the highest. In a similar vein, there are many world-class triathletes that train vegan, and using something as extreme as walking/jogging 100 miles at once as your metric is not applicable to most any other sport. The facts are there are THREE pathways for energy, and fat will provide ONE of them very well, if highly trained.
** Beta-oxidation (fat as fuel) = the "low octane" Gorbag was referencing. Used in LISS like ultras or walking.
** Glycolytic (glucose) = medium pace. Used in most jogging, tempo runs, most sports.
** Anaerobic (creatine) = short burst of 10 sec or less. Used in sprints, max out weights, etc.
So....unless you plan on doing a lot of Beta-oxidation level races like ultras, NO one races in ketosis. Many TRAIN in ketosis to up-regulate the pathway, but this is to lessen glycogen use in-race.
2) It is the MED? (minimum effective dose)
One can lookup a TON of diet and fitness plans that are effective, and some of them are rather miserable to do, such as ketogenic. In case anyone hasn't noticed, eating 30g of carbs a day for weeks on end is not fun....and pointing out that "it works" is not the intelligent question to ask. The question to ask is "Is this the most efficient way to get the result I want?"....for me, ketogenic never wins that litmus test. I have gotten down to 6%BF before without going keto (it was still rough), so I don't think it is ever the "most results with the least misery" winner, for me at least.
and @janie. I am an M.D. and hold a masters in cell-molecular biology...but no, one doesn't need that to know what they are talking about. No credential-hunting, it's rude and unnecessary. Just saying what everyone else was thinking when they saw that
Here's a lecture by Volek where he explains some of the low carb/ketogenic performance stuff that he's studied. The series is a bit long but really interesting. Towards the end (last segment, if I remember) he talks about a study in which the participants were put on a very low carb keto diet and a resistance training regiment, they burned a lot of fat of course, but more interestingly, they not only preserved lean mass, but added several pounds. Seems to fly in the face of CW a bit, but it makes sense if you listen to his explanation for how the calorie deficit/surplus really works when energy from body fat is so readily available and the body is deeply conditioned to access it.
Low-Carb Experts: Jeff Volek, MD, R.D., PhD - Segment One (9:23) - YouTube
Oh, and I've also lost 30 lbs - but that includes the one month prior to ketosis in which I just ate Primal.
Ketosis has been a breeze for me, except for the first couple of days when I was ironing out my electrolyte balance. I will never go back to higher carbs on a regular basis. The clarity of mind, consistent energy, great sleep, lack of bloating and so many other benefits make ketosis the best thing that ever happened to me, diet-wise.
The people that usually seem to do best in ketosis are those that have enough fat to spare on their bodies or stay away from high intensity/anaerobic training. No rules without an exception though...
ketosis is the best nutritional choice I ever made...feelings of euphoria, even mood, easily fast 20 hours, loss of cravings (except for butter lol),less bloating...the only difficulty I seem to have is a need to keep a strict rein on protein...since getting a ketone blood monitor, I've learned that it doesn't take much to knock me out of ketosis...an extra 2-3oz of protein and I barely register the next day...was wondering if anyone knew if there would be less gluconeogenesis on lifting days...I find that 3-4oz of protein 2x a day is all I can have...wondering if lifting would allow me to up that on those days...does anyone know how that works?
All you can do is experiment. Muscle-building protein synthesis happens over the course of days, not hours.
And remember that muscle retention is enhanced in ketosis, so you don't need as much dietary protein for muscle growth.
Also, you don't need to be in deep ketosis unless you have epilepsy, or another condition that requires it.