We've all heard about the benefits of exercise for our hearts
and to reduce cholesterol, but what about for happiness, improving
intelligence and memory as well as for alleviating addiction,
stress and aggression.
These are the findings from Spark: The Revolutionary New
Science of Exercise and The Brain, a book published this
year by John Ratey, associate professor of psychiatry at Harvard
Medical School in Boston.
Ratey believes that exercise is like medicine and helps depression
as well. This is supported by other studies. Depression scores
were measured in a German survey where for 10 days people
were asked to walk quickly on a treadmill for 30 minutes.
Researchers concluded at the end of the survey that exercise
significantly reduces depression.
Scientists at Yale University found that regular exercise
stimulates the hippocampus which is an area of the
brain responsible for mood. Their study of mice showed
that exercise activated a gene in the hippocampus called VGF.
VGF is linked to a chemical involved in new nerve cell development.
The findings have lead to scientists developing a drug that
mimics VGF gene workings in the brain. If so, this would replace
According to Ratey, exercise doesn't make you more intelligent,
rather it stimulates the brain making for improved learning
capacity thereby optimizing performance. Exercise increases
flow to the part of the brain which is responsible for
memory and learning. The stimulation improves brain functioning
in learning situations.
Some schools around the world have taken note and have instituted
exercise as part of the school day with teachers at Naperville
Central High near Chicago reporting improved exam results.
Other studies have correlated physical activity with improved
cognitive processing with the best results amongst people
who were the most active. A study in Germany found a relation
between the amount of activity in rats during pregnancy and
the amount of cells in the hippocampus of baby rats. The more
activity, the more cells. We'll have to wait to find out if
this applies to humans as well.
Increased blood flow to the brain also improves memory function.
From studies with mice at the Columbia University Medical
Centre (NY), new brain cells grew in the dentate gyrus area,
an area which is affected in old age. With new cell growth
due to exercise, memory would improve.
The findings about exercise reducing aggression are not new
-- we know that exercise is a good way to let off steam by
burning energy. However Ratey says that the reason aggression
is reduced is due to changes in the brain due to exercise
which removes the feeling of aggression.
Scientists in Britain found that just five minutes of brisk
walking can alleviate withdrawal symptoms caused from giving
up smoking. They believe that exercise stimulates how much
dopamine (a mood enhancing hormone) is produced which reduces
the desire for nicotine.
Ratey believes that a brisk 30 minute walk four to five times
a week is the minimum to achieve the benefits. He also recommends
interval training where you speed it up by sprinting for around
30 seconds then walking for two minutes.