(gentle music)
- Today, we are talking about fat.
And not how to lose it, but how to use it.
- Yeah and as you can see here, we have come to Porsche.
Sadly, not to drive these nice cars here today.
We are heading into their Human Performance Lab
for a FATmax test, which does not sound very nice at all.
Heather and myself are going to be finding out
when we burn fat, whether we need to be burning fats at all,
and more crucially, how we can get the most
out of this type of fuel.
- Yeah and we're going to be getting the help
of an expert nutritionist to help us analyse our fat data.
And well, I think, talking for myself at least,
I know I've got enough fat for this experiment,
so it's probably time we headed inside to find out more.
(digital sound)
- [Heather] Your body has a pretty much limitless
supply of energy that is stored as fat,
around 30 to 50 thousand calories
in an average healthy person,
compared with only about 2 thousand calories,
which is stored as carbohydrates.
Well, we want to find out how best to utilise this fat
as a fuel source.
Therefore, we needed to work out what pace or intensity
we should run at to use fat instead of carbs.
Well for that, we're heading into the lab.
(hype music)
- [Mark] All right, Jack.
I know we're going to be running today,
but what exactly are we going to be doing
in trying to determine our individual fat oxidation rates?
- Yeah, so today we are going to be looking
at a FATmax test
and that seeks to clarify two key variables.
One is the maximum amount of fat
that your body's capable of utilising per minute,
which is known as your MFO.
And then the second is your FATmax,
which is the exercise intensity at which that occurs.
- Okay and how are we measuring that today?
- Yeah so we're going to do that via
in that calorie machine.
So, we are going to have you on the treadmill,
and all wired up to our metabolic heart here.
We are looking at the gases that you breathing in and out,
the amount of those and the ratios of those
that tell us then about how much carbohydrates and fat
you are using to quantify those numbers.
- Okay, I'm run me through the test a little bit,
I'm a little bit nervous about it.
- Yeah, so the test is is a ramp test,
um, so it involves three-minute stages,
um, progressing by kilometer an hour
from what is a very easy pace,
because we want to look at your aerobic capacity initially,
up to your maximum capacity.
And that enables us to then look at your FATmax
as a proportion of your maximum,
which is always an interesting thing to know
as an endurance athlete.
- And one last thing, you um,
you've told us we're not allowed to eat,
which I'm pretty unhappy about.
Why is that?
- Um, so whenever you are doing a test like this,
it's really important to standardize things.
So, um, we want to make the test as repeatable as possible,
so controlling your eating and drinking is best done
by you drinking and eating absolutely nothing.
So you arrive fasting, so we can repeat that
in a future test.
Um, also, um those sorts of things can actually
influence the numbers that it will get on this test.
For example, if you were to have
quite a high-carbohydrate food or drink
right before you did a FATmax test,
that would suppress your body's fat oxidation
and leave you to have lower numbers on that.
Conversely, if you were to have a shot of caffeine
before you jumped on that,
that might be expected to increase your fat oxidation.
So the numbers might be influenced
if you did some of those things.
- Okay, well I think I'm going to go first
'cause I'm really hungry.
(hype music)
- So while Mark is jogging away in the background,
Jack could you tell me a little about, um this test.
How long it's going to take, do you think, on here,
and have you got any like initial reactions
from the numbers that we've just seen already?
- [Jack] Yes, so Mark's quite a fit guy,
so we'd expect this test
maybe to last a little bit longer than a less-fit guy.
Um, but in terms of what we looking at in the test,
I guess the key numbers that we get in real-time now,
the big one is a RER, or a Respiratory Exchange Ratio.
Basically, that's looking at the ratio of carbon dioxide
that Mark is producing versus the oxygen
that he is consuming.
- Yeah
- Based on that number, we can get an insight
into the amount and the proportions
of carbohydrates and fats that he is using.
So at the moment, he is at a pretty low speed for him,
and working predominantly aerobically,
and therefore utilising mostly fats as a fuel source.
And that's shown by an RER about .7
- Okay
- As speed increases now,
and the intensity increases throughout the test,
and we'd expect the RER number to climb um,
following exercise intensity to about .8, .85,
which suggests that he is using an a mix
of carbohydrates and fats.
And then, when we're working him really hard
towards the end of the test,
we'd expect that number to get closer to 1,
maybe a touch higher.
- Yeah
- which means he's exclusively using carbohydrates.
He's anaerobic then,
no longer able to use those fats anymore
- Yeah
- And therefore, has to rely on carbohydrates.
(hype music)
- Yeah, you're done, jump up on the side, you're done there
- Yeah, good work (clapping)
- 2.5, 20 seconds into 2.5
- That was tough, ready for breakfast now.
(panting)
Yeah, I'm interested to see what the results are.
I definitely felt it as we got around the 16 to 17K an hour.
I definitely needed something more,
and it just wasn't there.
Um, so there.
That was, that was interesting, it's hard,
and looking forward to seeing Heather give it a go now.
(hype music)
- [Heather] Well, we've managed to finish that,
and get some food in our bellies,
and take a little bit of a breath,
whilst Jack has been calculating numbers.
So Jack, now is crunch time.
Anything exciting, what news have you got for us
following these results?
- Yes, so I've had a brief eyeball of the data,
I still need to dive into it a little bit more,
but um, remember we talked,
we said that the MFO, the Maximum Rate of Fat Oxidation
was the one value that we were looking to get,
which is the maximum amount of fat you can burn per minute.
And for you Heather,
that came out as about .78 grams per minute, um.
And for you Mark, about .83 grams per minute, um.
Might not sound like much,
but in athletes adhering to a regular diet,
um the top range tends to be about 1 gram,
maybe just a touch higher than that.
So, in that sort of range,
you're towards the upper end of that,
which is which is always quite good.
- [Mark] Surprise to that.
- [Heather] Yeah, you are, yeah.
- The FATmax was the 2nd value that we were looking at,
and that was the intensity at which that occurred.
Um, we were doing a running test in terms of speed.
For you Heather, that occurred about 12 kilometers an hour,
or at 75% of your max.
And Mark, that occurred for you about 14 kilometers an hour,
or at 70% of your max.
- Okay, so what does it say um,
you know your an Ironman athlete or endurance athlete,
and you've watched this,
and you think
"Great, I want to teach my body
to be able to burn more fat",
then is there anything Mark and I can do if we were,
if I'm doing ultra-marathon
or if Mark was going to do anything longer,
that we could do is try and increase
either of those numbers?
- Yeah sure.
So I guess, the two key things that you can do
if you are looking to improve those numbers,
um can be split into your training or exercise and,
and your diet.
Adhering to low-carbohydrate high-fat diets has indeed
been shown to improve these numbers in a test.
So I mentioned that about one gram per minute
is roughly the top end for people adhering to a normal diet.
Those that stick to more of a high-fat diet,
over a period of maybe three to four weeks plus,
you'd expect those numbers to maybe increase closer
to 1.5 grams per minute,
which might not sound like much again,
but that's a big that's a big increase.
The the only issue with that fat adaptation is that,
a repeated finding in the literature is that,
when we become fat adapted,
we potentially limit our ability to utilise carbohydrates.
We've been talking a lot about fat here,
but carbs are still very important
for most endurance athletes,
in the majority of contexts.
Carbohydrates are more more important
at those higher intensities,
so any sort of sporting sort of competition
that involves the need to go to higher intensities,
and these are often the pivotal moments
in a lot of endurance sports,
it could be a key climb, a breakaway, a sprint.
If you're fat-adapted and
and compromising your ability to utilise carbohydrates,
that might affect your ability
to to to to perform well in those instances.
- So you're essentially,
you're almost becoming a bit more of a diesel engine,
which might suit your age-group Ironman athlete
who wants a steady pace,
then say like a sprint distance or Olympic distance ready,
it's quite punchy
and trying to make those big surges of pace,
then maybe you don't need to worry
quite so much about fat oxidation.
- [Jack] Exactly, so it comes down
to assessing the needs of your sport really.
So, the balance of literature at the higher-carb approach
for the people who are in those sports,
where there are um some harder efforts
interspersed amongst more low-intensity efforts
that that that higher-carb traditional approach
is the safe way to go.
But interestingly, a new emerging sort of area of research,
over the past decade or so,
is looking at rather than low or high-carb,
smart-carb intake as some people have called,
or carbohydrate periodisation, whereby you periodise
your carbohydrate intake and availability
around a purposeful goal
of a training session or training block.
- [Mark] And are there any extra little things
that can help metabolise fat?
- Yeah, so I think the main two things
as we said are your training,
making sure you get as fit as you can,
and the adaptations that you get
from endurance training will leave your body
in the best state possible to metabolise,
not only fats but carbohydrates as well.
Um, we mentioned the idea of that smart-carb approach
so perhaps playing around
doing some of your lower-intensity sessions
with relatively low-carbohydrate availability.
Um, in those sessions,
caffeine might have a beneficial effect.
It can potentially help to mobilise some of your fats stores
that make our body better able to burn those effectively.
Um, and it could also help compensate
for the lack of breakfast that you have,
and give you a bit of boost in that respect.
Other things that you might see out there,
like fat burners, any supplements labeled as such,
I'd be very skeptical of,
the the the research supporting those is definitely lacking.
So, stick to your hard training,
maybe focus on a few little smart things
you can do with nutrition,
and a bit of caffeine.
- There is so much to consider
when you are thinking about using fat as fuel.
But, probably the two main points
you want to think about
are the distance of your race,
and also what your goals are for that.
And it definitely got me sort of thinking,
with my ultra coming up
of maybe if I wanted
a little bit more fat burning with that.
- Yeah, this has certainly been a fascinating day,
so a big thanks to the guys here
at the Porsche Human Performance Laboratory.
Um, I'm really surprised personally by my results.
I definitely thought I relied on sugar a lot more
than I clearly do, which is obviously great
for Norseman that I have coming up.
So, I don't know,
I think I will still going to carry on with as many gels
as I maybe was planning to go in in there with.
But, definitely great to know
that I have that capability within me.
- Yeah well, if you have enjoyed it,
give us a thumb up like, and hit that globe
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And if you want to see the video
where we looked at the ideal weight for training and racing,
it was a triathlon training explaining show,
and you can find that one just over here.
- Yeah, if you'd like to see another video
that we actually shot right here
at the Porsche Human Performance Lab we did about
sweat rates, and also more crucially
how much salt within that,
you can see that by clicking just up here.