This year I made a New Yearís resolution to do more runningólike all those other people
who are likely to make New Yearís resolutions (actually 44% of Americans) and those who
are likely to resolve to exercise more (12% of those turning over a new leaf).
So on New Yearís day I downloaded a new app, obviously ëZombies, Run!í will help, and
decided to train for a race across the Sydney Harbour Bridge.
Of course doing regular exercise is good for your body, but the health benefits don't stop
there.
Physical exercise is also good for your brain.
One study split their participants into two groups, one that did an aerobic exercise class
every week for a year and another that did a stretching class.
Those in the exercise groupówho did 40 minutes of aerobic walking every weekóshowed improvements
on a spatial memory task, identifying where small dots flashed on a computer screen.
This improvement was directly related to some of their brain structures increasing in sizeójust
from exercising.
Their hippocampus, the brainís memory and learning centre increased by an average of
2%.
But for those in the stretching group, their hippocampus decreased in size by 1.42%- not
surprising as peopleís brains can start deteriorating from as young as 30 years old.
Data suggests thereís a significant positive relationship between physical activity and
cognitive functioning in children too.
In one study, 9 and 10 year olds who performed better on a fitness test had larger hippocampal
volumes and a better performance on a memory task.
So as well as strengthening muscle cells, exercise strengthens brain cells.
Researchers believe some of these benefits come from a protein in your brain called BDNFóit
stands for Brain Derived Neurotrophic Factor.
Exercise like running stimulates the production of BDNF in the brain.
BDNF promotes the growth of dendritesóthe branches of neuronís cell bodiesóand the
strengthening of synapses, structures that let neurons communicate with each other.
So BDNF increases the connectivity between your neurons in brain structures like the
hippocampus, which is crucial for some aspects of your memory, like spatial memory.
It makes sense from an evolutionary standpoint.
If youíre going out on a runóor aerobic walkóto find food or shelter, an increase
in BDNF in your brain would promote the retention of your memories of what you find.
So jogging can actually jog your memory.
Exercising your brain cells might change the way you think about your New Yearís resolutions
or your morning run.
Or, it might just change the way you think.