P E T S
sedentary mates. These factors exist in all
species and are called ’miracle-growth factors
for the brain’ by some scientists because they
stimulate the formation of new connective
bridges between nervous cells from scratch,
potentiating the brain activity at any age.
Even gentle physical activities increase the
connectivity and boost memory.
This body-mind connection is rooted in the
evolutionary memory of all creatures. Probably
the brain boost mediated by growth factors
emerged to improved orientation during
foraging activities. When animals forage there
is an automatic cerebral production of growth
factors that accompany their wandering,
which in origin was probably an accidental
by-product of the evolution lately turning an
important survival strategy.
In fact growth factors stimulate the neural
and synaptic growth of cerebral cells, helping
animals to remember the paths and the best
pastures, so they can revisit the locations in the
near and remote future. A study which followed 1500 people for 20 years
came to the conclusion that these effects are
long lasting because those who exercised at
least twice a week during their middle age were
less prone to develop dementia in their 70s.
Human mysteries
Physical agility, rapidity of reaction and
performance are strictly linked to the activity
of trained brains in humans, but with some
differences compared to animals. Younger
people and athletes react more quickly than
older and sedentary potato coaches. Mysterious turning points in our prehistory
proved determinant in the creation of a brain-
body link. Our ancestors accidentally trained
as long-distance runners because of their
need to forage and hunt big prey: gazelles,
antelopes, deer and buffalo, even horses.
Trekking faraway to catch their food, they
would have experienced that increased surge
of neurotransmitters, serotonin, noradrenaline,
dopamine, and growth factors, BDNF, IGF1,
that ultimately led to the appearance of
intelligence.
It is not only a matter of muscles, resistance
and strength. Mental activity is fundamental in
boosting performances and vice versa is also
true, because exercise is an enhancer of normal
cognition. Decline in fitness explains why some
people are more prone to dementia, but this
was not so obvious in the recent past.
A link between physical fitness and mental
brightness was first suggested during the 1960s
but it was only in the 1990s that the California-
born geneticist Fred Gage realised that exercise
helps the growth of neurons.
Exercise Research
The authors of an article published in Nature at
about the same time observed that sedentary
people given a boost of exercise for 6 months
had better cognitive skills compared to controls
who did not exercise, thus they became more
intelligent.
Regular training can influence performances
in mature and even elderly people and
animals reducing reaction times and increasing
resistance.
Marathon brains
An active brain requires a lot of nutrients,
oxygen and at least 20% of daily calories.
Exercise helps to build the neuronal capillary
network and its maintenance. By reducing
blood pressure, regular physical activity protects
the brain arteries and provides a steady supply
of nutrients. Exercise regulates the signalling
activity of neurotransmitters and cuts the risk
of Alzheimer’s, a disease associated with
the formation of fatty plaques, nicknamed
‘diabetes of the brain’, that causes brain
damage by altering the brain insulin system.
Alongside these dreadful effects due to lack of
exercise, for reasons that are still debatable, we
hold far better athletic endurance than most
animals and certainly more than our primate
cousins. A chimpanzee or a gorilla would
never run a marathon. Some would argue that
healthy animals including humans, generally
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