- What if I told you you could lose weight,
lower your blood pressure, lower cholesterol,
increase your lean body mass percentage,
protect against disease, and live longer
all without changing what you eat,
but instead changing when you eat it?
Sounds too good to be true, or perhaps it isn't.
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These are some of the benefits that have been linked
to intermittent fasting, a form of eating where during
a typical day, you'll have strict periods of eating
followed by disciplined periods of no eating or fasting.
In this video, we're going to explain what it is
and also how it could improve your health
and also how it can be beneficial
within the context of a cyclist,
and if you like this content and would like to support
the channel, then you can do so by subscribing.
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The Internet is currently awash with so called health gurus
selling their latest fad diets, and that being the case,
I've decided to put in a quick disclaimer.
I have no agenda here.
I'm not trying to sell anything.
I simply took the time to research this
because I find it interesting,
the scientific merit behind it,
and hopefully you'll find it interesting too.
Fasting basically involves extended periods
of not consuming any food, and there are different forms
and protocols for intermittent fasting,
arguably the most popular is a form called 16:8.
This involves an eight-hour eating window in your day
followed by 16 hours of not eating or fasting.
Now it sounds tough, but it's not as tough
as you might think.
So for example you could eat your evening meal at 6:00 p.m.
and then not consume any more calories for the rest
of that evening, go to bed, wake up,
and then not have breakfast until 10:00 a.m. the next day,
perhaps after your commute when you've got into work.
However this could be tweaked and played around with
to suit your individual schedule.
Other versions of fasting include 24-hour fasts
where you fast 24 hours.
Perhaps you do this once or twice a week.
There's also the warrior diet which is a process
whereby you consume all of your daily calories
in one sitting in an evening meal, a practice inspired
by the imagined activity of early hunter-gatherer
homo sapiens going out and hunting all day, having a kill,
and then cooking it in the evening.
And you may have also heard of the 5:2 diet as well.
The point is there's loads of different versions
of intermittent fasting.
With the exception of the 5:2 diet,
during the fasting period, no calories are consumed.
The idea here is to avoid anything
that would trigger an insulin response.
You are allowed to drink tea though
and electrolytes and water,
just no milk in your hot drinks,
and obviously no cake either.
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So how does it work?
Well, the basic premise is that you schedule times of eating
and times of not eating, fasting, into your day.
Now the effect of this is that it reduces
your glycogen stores or sugar stores
and enters your body into a fasted state,
and when in a fasted state your body then turns
to stored fat as fuel.
This has a two-sided effect on weight loss.
By thinking more about what you eat
and potentially snacking less in between meals,
you may take on less calories and effectively lose weight
that way, but it also changes the way that your body
responds when you do consume food,
and that is where it gets really interesting.
Intermittent fasting may help with weight loss
by lowering insulin levels.
Now when you consume carbohydrates, your body
breaks them down into glucose,
and this is used by your cells for energy,
or if you don't need it at the time, it's converted into fat
and stored so that you can use it later on,
and insulin is a hormone that allows cells
to take in glucose.
When you don't consume food or you fast,
insulin levels drop, and this is thought to encourage cells
to release their sugar or glycogen stores to be used
as energy, and this isn't just anecdotal either.
A 2015 systematic review in the Journal of Molecular
and Cellular Endocrinology,
one of my favorites,
looked at 40 different studies on intermittent fasting.
The researchers concluded that intermittent fasting
is useful for reducing body weight.
There are potential cardiovascular benefits too.
It can be useful for lowering your heart rate,
your blood pressure, your cholesterol, and triglycerides
which is the fat present in your heart
that's linked to heart disease.
If we decrease insulin levels, then our body
has a better chance of using energy stored in fat cells
than instead relying on easy access carbohydrates.
There is also compelling evidence
that it could be beneficial to people
who are at risk of diabetes as well.
So a review on intermittent fasting in 2014
found that it does lower blood glucose levels
and insulin levels.
Fasting can also increase levels of autophagy.
What is autophagy, I hear you ask.
Well, it's a really really important process in the body
that's used for recycling and repair where damaged cells
or proteins are broken down and used as energy or repaired.
Now if your cells are really well fed
'cause you're constantly feeding them Haribo all day long,
then they're not bothered about repairing themselves.
All they want to do is grow and divide as much as possible,
but through fasting you stimulate autophagy,
and then this activates pathways in the body
which inhibit mTOR production.
mTOR is a protein and it helps regulate the growth
of your cells and also the rate at which your cells divide.
Now over activation of mTOR,
i.e., if you have too much of it, can contribute
to the initiation and the development of tumors,
and it's been found that in many types of cancer
there is deregulation of mTOR,
i.e., there's just loads of it.
Now more studies into the links between this are required,
but it's one of the ways in which fasting is thought
to contribute to an extended lifespan,
and a 2018 study in cell metabolism looked
at the lifespan of mice.
The really interesting thing here was that
by subjecting these male mice to fasting protocols
and long gaps in between meals, they lived much longer,
much healthier lives irrespective
of what the content of their diet was.
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So how could fasting be applied to cycling?
Well, the first thing to point out is that
although you can go for a ride while fasting,
it's not technically the same as just going
for a fasted ride, which you may have heard of in the past,
but you're going to struggle to do anything other
than just low-intensity riding while fasting,
and the reason for that is that you won't have
sufficient blood sugar and glycogen stores
which is essential for doing any high intensity work.
Also factor in that if you do a big fast,
don't expect that you can suddenly do
really hard training the next day.
It takes 22 hours to four days to fully replenish
the body's glycogen stores once they've been depleted,
and that's where the problem comes.
Most of us stand to gain far more by doing
as much quality training as possible.
Many of us are time crunched
meaning that we're better off spending the limited time
we do have to train doing high-quality high-intensity work.
If you get the timing of a fast wrong,
then you won't have sufficient glycogen stores
to perform a high-intensity workout or in an event,
and then the key thing for cyclists
if you're going to be doing high-intensity,
is to keep your glycogen stores topped up
because it's the best fuel for performing that kind of work.
However everyone's different.
You might not be trying to be as fast as possible.
You might not be training to win the Tour de France.
So if you're happy at riding at a lower intensity
and you're trying to get a bit leaner and lose some weight,
then fasting is something that's probably well worth
trying and incorporating into your training and riding.
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So how about arguments against intermittent fasting?
Well, it can be antisocial.
It could mean not going out in an evening
if that evening involves any kind of consumption
of calories whatsoever.
Although it could be argued that it can be flexible,
and you don't need to follow it every single day.
Cheers, John.
So to summarize, fasting may or may not be for you.
There's no one-size-fits-all when it comes to dieting,
and if weight-loss is your goal,
then you need to find something that works for you.
Just make sure that it's built around
a healthy balanced diet and an active lifestyle.
In the words of Tillman Kern
from the German Cancer Research Center
who conducted the largest investigation to date
on intermittent fasting, it's not primarily
the dietary method that matters, but more importantly
to decide on a method and follow through with it.
Right, I hope you found this video interesting
and informative, and if you have,
then please give it a thumbs up
and share it with your friends.
And at the moment, the science is still ongoing.
We still don't fully understand the benefits and limitations
of intermittent fasting, and further study is required
before we truly know what is the best protocol for it
whether that's a 16:8 or a 5:2 diet or a 24-hour fast.
We simply just don't fully know yet,
but this is a subject I'd like to revisit in the future.
Now if you'd like to watch another video on the keto diet
and how that can be applied to cyclists,
then click down here.