What happens when you exercise? Chemistry Calendar, August: Sports

Uploaded by MoleCluesTV on 25.08.2011


Training log day 14.
Last day, day 14 of inactivity period.
It has been two weeks since we’ve done any exercise.
I’ve been quite tired.
And you would think that conserving all this energy for two weeks
you would have more energy.
But that’s not the case.
Well, let’s take a look back 14 days.

So we’re on our way to the clinical nutrition department here at the university
to do a little chemistry experiment.
We want to find out how our bodies use of energy
is related to the amount of exercise we do.
But first, let’s explain the basics of energy.
Energy can not be used up, just converted into different forms.
The food we eat contains chemically stored energy,
in the form of energy-rich molecules such as carbohydrates, proteins and fats.
When we do physical activity these large molecules are first broken down
to smaller molecules, such as glucose, that are transported to the muscles.
Oxygen, which is also needed in this reaction is transported from the lungs
to the muscle where it reacts with the glucose producing carbon dioxide and water…
and small molecule called ATP, which is our bodies’ energy currency!
But we often hear the term calorie, or kilocalorie,
when we talk about energy in food.
A kilocalorie is actually a way to measure energy and it’s defined as the energy needed
to increase the temperature of one kilogram of water by one degree Celsius.
And to understand the meaning of this kilocalorie term
in relation to how our bodies work,
we are going to do a little chemistry experiment.
So the experiment that you are going to perform right now
is that during two weeks you’re going to be as passive as possible
with as little exercise as possible.
And then during two weeks you will exercise as much as possible,
and then we will see how big the difference is in energy expenditure.
So this is how we can do this.
First we will drink a dose of so called double labeled water.
It's normal water except that both the hydrogen and oxygen atoms
are isotopes of their normal form.
An isotope has the same number of protons in the core
but differ in the number of neutrons.
This water will then mix with the water we already have in our bodies,
and follow the water’s normal pathways.
All the marked hydrogen will go out in the urine together with some of the oxygen.
The trick is that we will exhale some of the marked oxygen as carbon dioxide,
and we will exhale more carbon dioxide if we train.
Quite simply because we breathe more when we train, right?
So depending on how much labeled oxygen and hydrogen we can detect in our urine,
we can also calculate how much energy we have used!
So first, we wanted to investigate our energy expenditure during rest...
Which meant, doing everything we could to do as little exercise as possible,
but still live a normal life...

Seriously, this isn’t training.

And then, it was time to drink a new dose of double labeled water
and begin two weeks of hard training.
And to help us do that, we have our very own personal trainer,
Moa Nilsson at FUSTRA

Okey, so we’re done with two weeks of training,
now it’s time to compare the results.

The chemical analyses of the double labeled water from our urine samples
showed that I went from using around 2500 kilocalories per day during inactivity
to around 3800 kilocalories during weeks of training.
And I went from using about 3000 kilocalories per day,
to about 4700 kilocalories per day.
Well if we start with the inactive period that you had we can see
that you had a very low energy need and you had very little physical activity.
And that is shown to increase the risk of several diseases
like heart diseases, cancer, overweight and obesity.

It may be obvious that the total inactivity option is not recommended.
But what I found really interesting is that we can use chemical isotopes
of hydrogen and oxygen in water to put a number on how many calories,
or chemical energy, our bodies simply need to function and to do hard work.
And it turned out that saving our energy, by doing hardly any exercise at all,
actually made us even more tired.
Why do you think that is?

A chemical experiment, like the one we just did,
can give us valuable information concerning physical activity, different lifestyles
and our overall health.
But chemical research related to sports is so much more than this.
For example, a lot of biochemical research is done to understand how our bodies
make use of different sources of energy and how this may change
during for example long-distance training.
Studying and understanding oxygen uptake and transport
help athletes train more efficiently.
And chemists are also working to come up with improved materials in sports equipment.

So, get out and burn some chemical energy, just remember to eat right as well.
Because, you know chemistry is all around you,
and inside!