Dr. Jeff Volek – Physical Performance and Ketogenic Diets

Dr. Jeff Volek – Physical Performance and Ketogenic Diets


– I told you yesterday I started
my obsession with wanting to study ketogenic diets
in grad school in the 90s. I was in an exercise science
lab and I made the fatal mistake of actually reading
Steve’s studies, and Tim, your studies as well. The Lambert Study, which were the two key high fat diet studies,
and I read them 100 times and highlighted every line in
those articles and shared them with all my peers and my
professors and begged my advisor to let me study this, and they thought I was crazy. But after begging for three years they let me start a study in this area. So that was my mistake is
actually believing those studies had some merit. In many ways, it took me a
while to actually study it, exercise related aspects
of ketogenic diets, because I got more interested
in cholesterol metabolism. The FASTER Study was one
effort to really validate Steve and Tim’s work and extend
it in some ways in terms of the metabolic adaptation. This was a study that I did right before I left
University of Connecticut to come to Ohio State,
and it was in many ways a rather straight forward study. It was a cross sectional study in elite athletes, and we had the goal of just trying to
convince what, at the time were a growing group of high caliber
ultra endurance athletes that had switched to a low
carbohydrate, ketogenic diet. Okay, what am I doing wrong here? Wrong remote. We published some of this
work, we actually have a lot of work we haven’t published. I might share some of
that with you in time but a shout out to some of my doctoral students who need to
get the papers out here. Dr. Signs, we have some
really fantastic data. But we did publish the
primary metabolic data, and we were successful, which was probably the most
surprising part of the study was how easy it was to convince people to fly to our lab at the
University of Connecticut and go through some very
invasive procedures, inject isotopes into
them, cut into their legs, and extract muscle tissue. We were collecting urine
and feces and saliva, everything we could get out of these guys and they left thanking us. Honestly, they were so
happy to participate. Just a tremendous group of athletes. We got 20 total, nice
symmetry here, 10 and 10. So we had 10 very high level ultra athletes that had been
on a low carb diet for at least a year, but the average
was closer to 20 months. So that’s kind of important. We’re studying long term,
chronic keto adaptation, and then we had the control, high carbohydrate athletes. It turned out they were very well matched. Same physical characteristics,
even the same VO2 max. So really the primary
difference here is diet, and you can see the macro
distributions there. These were pretty low carb, 10 to 12% carbohydrate for 20 months. It’s just a picture, the
primary protocol we had them go through was a three
hour run on the treadmill. They literally started at a brick wall that had white bricks on it, and this is a warm up
for many of these guys that are running 100 mile
races and other types of ultra endurance events so that’s not as brutal as it sounds to probably most of you. Then we had them go through
a variety of different procedures, including muscle
biopsies, and blood draws, etc. So, one of the primary
outcomes of this study was just documenting their peak fat burning. As Tim mentioned earlier these were extraordinary
rates of fat oxidation. Literally, two fold higher rates. The fat oxidation in
the high carb athletes is actually very high. Point seven grams per minute. These are exceptionally good fat burners and exceptionally good athletes. But we literally doubled
that with the adoption of a low carb diet. And prior
to that, no one had really ever shown a fat oxidation of that level. If you look throughout the literature again point seven’s pretty high and if you look at individual values and some of the studies
that have been out there you see a few people get up
close to one gram per minute so we literally shattered
the fat burning ceiling here by documenting this in these athletes and it occurs over a wide
range of exercise intensities so this is sort of a classic curve you get as you go from low to
moderate intensity exercise you see a pretty linear
increase in fat oxidation and then it drops off pretty fast as you increase exercise intensity but everything’s moved
far up and to the right when you’re keto adapted. So you can burn more fat at
any given exercise intensity and you can burn more fat at
higher exercise intensities and Tim showed you this graph so you’re deriving the majority
of your energy from fat during three hours of submaximal exercise, and it would’ve been really interesting to carry these guys
out another three hours and I think you really start to see and distinguish the benefits
of being keto adapted because you’re just much
less dependent on carbs. And you see the ketones here so you do get this classic
post exercise ketosis or Courtice-Douglas
effect as its referred to but not surprising their
ketones are higher. Measures of lipolysis,
this is serum glycerol not surprising. They’re breaking down fat at a higher rate so at least part of that
sub straight to support the higher fat oxidation is coming from adipose tissue, triglyceride lipolysis. But perhaps most surprising, I mean if not bizarre and probably the most important
non significant result I’ve ever reported is that
glycogen was completely the same between the high carb athletes
and the low carb athletes despite the fact they consumed
very little carbohydrate. At rest they’re the same and
they did break down glycogen after the three hours of exercise and even resynthesized glycogen
over two hours of recovery which is absolutely astonishing in the face of very
little carbohydrate intake and we’re still kind
of scratching our heads wondering what’s going on here and if you actually calculate
the amount of carbohydrate they oxidized during exercise it’s about 100 grams less than what this glycogen depletion shows so the obvious question is where did that glucose
that was broken down from glycogen go and why
would they even do this if they’re burning fat
at such a high rate? The short answer is we don’t know. I mean, we have a couple
working hypotheses. One is, for those of you
who’ve studied metabolism in the text books you’ll
read that fat burns in the flame of carbohydrate which makes no sense but biochemically it’s derived from this thought that in order to keep the Krebs cycle running you have to maintain a
source of oxaloacetate and that, that’s how you burn fat. In oxaloacetate is derived
from glycolysis or glucose so one thought is breaking
down glycogen during exercise provides a source of
glucose to make pyruvate which can be converted to oxaloacetate and keeps that Krebs cycle
running so you can burn fat but that glucose is
not terminally oxidized and doesn’t show up in indirect calorimetry type measurements. The second thought is that
you need a source of glucose not for glycolysis but for
the pentose phosphate pathway which does operate sort of
in parallel to glycolysis and produces five carbon sugars and is also a source
of reducing equivalence which is important for
various reactions that might be beneficial for recovery or for energy metabolism. But what I think this shows is that when you’re chronically keto adapted, because this wasn’t shown
by Steve after four weeks is the body conserves carbon sources within the glycogen
and glucose and lactate sort of interconversions very efficiently. It’s very likely this
carbons that are used here to synthesize glycogen are coming perhaps from lactate. Or that’s either directly a
source for glycogen synthesis or going to the liver,
being converted to glucose and then coming back as a
source for glycogen syntheses. That’s the cori cycle. Any rate there’s a lot of interesting work that needs to be followed up on here in terms of describing
that and validating that. I just thought I’d show you quick, this hasn’t been published,
this paper is in review but these very healthy,
highly insulin sensitive keto adapted athletes that
are performing really well have super high cholesterol
levels, almost all of them. You can see here the
almost two fold higher LDL cholesterol levels. Every one of them should
be on a statin, right? But look at the HDL cholesterols. I mean I’ve done cholesterol levels on thousands and thousands of people and I’ve rarely seen people over 100 milligrams per deciliter and we’ve got half that
cohort over that level. So when you look at the
LDL to cholesterol ratio or total cholesterol HDL
ratio it’s actually the same in these two groups, and we look at particle
distribution by NMR despite having almost
twice the concentration of LDL cholesterol they have fewer small LDL cholesterols
and we heard about this from Ron yesterday and this is actually consistent with a lot of the work that I did initially on ketosis and
glycol protein changes. So all the increase in LDL cholesterols in the larger, more buoyant particles which Ron said yesterday were okay, they don’t contribute to increased risk for cardiovascular disease. And we’ve obtained a lot
of other interesting data from this study from the muscle biopsies. We’ve done full transcriptomic analysis and gene expression
and metabolic analysis, fatty acid composition in the muscle and everything looks great. It also ports the greater fat oxidation their phospholipid
membranes have higher levels of unsaturated fat and they’re more fluid and less saturated fat which is consistent with improved health. There’s just a lot of
other interesting things that we’re still yet to publish. But this was a cross sectional study and I think limitations
in cross sectional studies is you don’t know, you can’t
deal with the self selection and whether or not these
people that are keto adapted or choose to keto adapt
have some unique feature about them that lets them be successful. So perspective studies are always nice to look at changes over time and so we decided to do a well
controlled perspective study and we’ve had a strong interest in how we can enhance soldier health so we had a very strong military relevance to this type of study and the military has the same problems as the rest of the population. This is a recent white paper that came out showing that in young
adults 17 to 24 years old 71% of them are actually
ineligible to join the military even if they wanted to
and the primary reason is because of health
problems, mainly obesity. So we just finished data collection and this was a big study
in my lab last year in terms of consuming a
lot of our time and effort. Rich Lafountain and Vin Miller were the primary lead on this project but Terrance Zapper
head of my dietetic team ran all the dietary
intervention aspect of this and everyone contributed, but
it was a 12 week intervention. We provided a lot of the
food to the participants and the subject population was primarily army ROTC cadets on campus as well as others with
military affiliations. We had a control group too. We trained all these
groups, supervised training and we had a very well
formulated ketogenic diet we wanted to implement and
we were very aggressive in maintaining ketosis. We had them check their ketones every day and adjust the diet if necessary and I think this is one of
the more important findings. Just the fact that we can
keep these relatively young men and we had a couple of
women in the study as well in ketosis demonstrates
feasibility of this in a relatively college age population ’cause the military doesn’t
think this is feasible at least a lot of the people I talk to but we had an average ketone
of over one million mmol/L and very good compliance
across all the subjects so they were in ketosis and this is the results in weight loss, and this was not a
weight loss intervention. We specifically did not
prescribe a caloric level. We wanted people to be in ketosis and we wanted them to be happy so we fed them the most
palatable and satisfying diet we could, those were the
two main goals of the diet. So this is a spontaneous
reduction in calories as a result of being in ketosis and it’s really quite
dramatic how this played out. You can see every single
person lost weight and again this was not
a weight loss study, compared to, you know virtually no change in the control group
and they lost body fat. We did DEXA, we did MRIs
to look at visceral fat and liver fat and
everything’s looking better. We had an indication as is the
case especially with training is you see rather transformative changes in body composition, especially when you
add resistance training to the ketogenic diet. And I don’t have all the data
here but their performance and their adaptation to the training more or less mirrored that
of the high carb group. So they’re losing weight
but still getting stronger and adapting to the training in terms of a lot of measures
of physical function. Strength, power, endurance and
even cognition data we have. And we have muscle biopsy data from this. Vin Miller had on a poster yesterday looking at a lot of
mitochondrial adaptations and Rich Lefountain had a
poster on cardiac adaptations from MRI and we’re seeing
positive adaptations in those particular aspects of physiology. So this is my last slide. There’s a lot to talk about here in terms of why an athlete might
consider a low carb, high fat ketogenic type diet and it goes beyond just
enhancing fat oxidation, that’s a big fundamental part of why you would consider it but a lot of what we heard about earlier on ketones being signaling molecules and creating an environment
of less oxidative stress, less inflammation, all sort
of ties in to the ability to recover and adapt to
training at a higher level and in the long term view of an athlete those are big factors to consider. It’s not just about acute performance and doing anything you can to enhance performance
metabolically by carb loading and enhancing availability of glucose. That sort of short term
gain, long term loss in terms of a lot of the toxic byproducts of burning carbs all the time. So this is what we hear
from a lot of the low carb, high fat athletes. They’re bonk proof, they recover faster, they enjoy exercise more, they have less need to
fuel during exercise. All these factors I think,
you know you’ve gotta consider if you’re working with an athlete or considering this yourself in terms of choosing which diet to follow.

4 thoughts on “Dr. Jeff Volek – Physical Performance and Ketogenic Diets

  1. Fascinating. Just anecdotally doing long endurance (for me) has been helped a lot being in ketosis. (And I am an insulin resistant person)

  2. Dr. Volek’s talks are always very informative and fascinating. This is evidence based science, not anecdotes. Anxiously awaiting the additional data from FASTER!

  3. As we can see from the comments, the masses gobble and become exuberant and irrational about the miracle "ketogenic cure".
    Volek, however, never talks about the high level of cortisol, the low level of thyroid, the abysmally low testosterone levels in "ketogenic" athletes. There are many questionable or outright detrimental "adaptations" that accompany higher levels of ketones in the blood. By the way, the early adopters of "keto", the elite endurance runners, have already left behind the "keto exuberance". They do restrict carbs but they are not in ketosis. Or maybe occasionally. Their health is better. Check Peter Defty's most recent interviews.
    twitter.com/nneandertalienE

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