Dr. Jeff Volek – Physical Performance and Ketogenic Diets

Dr. Jeff Volek – Physical Performance and Ketogenic Diets

August 1, 2019 4 By William Morgan


– 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.