I probably hit about over a thousand forehands a day.
I'm a perfectionist, so I like to get everything pretty spot on.
This level of dedication has enabled Freya to develop her sport
to the very highest level,
but such sustained activity has also left its mark on her body.
And what's interesting about tennis is that we can see exactly how
her body has adapted and learned.
Because tennis divides the body in two whether it's serving at 100
kilometers an hour
or smashing forehands down the line.
Powerful impact forces are experienced far
more frequently by Freya's racket arm,
and that level of force causes some surprising,
one sided changes to the skeleton.
We are only just beginning to uncover.
While her body looks symmetrical from the outside.
The bones in her racket arm are 20% thicker
and contain more bone mineral than her other arm.
Her joints
act like shock absorbers, taking up the extreme forces,
her arm experiences repeatedly as she hits her shots.
These forces are transferred from muscle
along her tendons to her arm bones.
Freya's skeleton has learned to cope with her intense daily workouts
by growing dramatically in order
to reduce the risk of breaking.
Tennis players,
we have to really focus on keeping the balance right.
If you get too much on one side, then it can really throw things off.
In fact,
we all have small differences in the size of the bones in our arms
because everyone tends to favor
one arm over the other.
But recent studies have shown that the differences in tennis
players are about ten times greater than in non-players.
And it's not just our bones
that adapt and learn to deal with the stresses and strains of life.
It's our muscles as well, muscles that will need to be on top form to beat.
Andrea Petkovic, former world top ten player
muscles also
learn from the activities we do every day.
In fact, skeletal muscle is the most adaptable tissue
in the human body.
Muscle fibers cells
contain more than one nucleus.
When muscles are worked hard, special
satellite cells are activated.
They divide.
One of these cells then fuzes with the muscle fiber itself.
Now, with added nuclei, the muscle fiber cell builds
more myo fibrils increasing the size of both itself
and our muscles, giving Freya more power for her shots.
But in the end, this
experience wins over power.