Healthy body, healthy mind

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Exercise is great for the body, but brilliant for the brain, writes Dr Adam Fraser.

To get ahead in life we rely on brainpower. For some people that means the body gets little attention. But would that attitude change if those people realised what we do with our bodies helps us achieve more with our brains?

Traditionally we have viewed exercise as something that only helps us live longer and look buff in a pair of swimmers, but new research has shown exercise switches the brain into top gear by speeding up neurogenesis (the production of new brain cells). Until only a few years ago neurologists thought the brain did not have the capacity to change or generate new cells. This is not the case, however. We now know the brain is incredibly “plastic” and can change its structure and function. The definition of a plastic brain is one that can generate new cells and encourage more cells to connect to each other. Exercise helps this happen, and it has also been shown to reduce the impact of ageing on the brain.

Here’s how exercise keeps the brain, as well as the body, supple.

Remember your hippocampus
There is a banana-shaped region deep in your brain called the hippocampus. It is thought this region is involved in the storage of memories and recollection of information. In Alzheimer’s disease the hippocampus is one of the first regions to suffer damage. Studies show that exercise dramatically increases the number of brain cells generated in the hippocampus, therefore helping us learn, recall information more quickly and preventing us from developing brain diseases such as Alzheimer’s.

Brain training programs that promise to keep the brain young have become very popular. But how do they stack up against exercise? The Gage Lab in the US compared the effect of brain stimulation (toys, tunnels, mazes, etc) and physical exercise on the brains of mice. They found the subjects in the exercise group were the only ones that showed an increase in neurogenesis. In other words, exercise wins.

Blow your mind back up
When you hit 40 the brain starts to shrink, especially in the regions that are responsible for memory and higher cognitions. As little as three hours a week of brisk walking has been shown to not only halt this but actually reverse it, leading to greater brain volume.

You don’t have to wait long for the benefits; as little as three months can Improve your brain volume to the same as someone three years younger.

The red and the grey matter
Our greatest chance of exhibiting a mental illness (bipolar, schizophrenia, psychosis, mood disorders) comes between the ages 15 and 25. Later in life, after middle age, we see a similar peak with a huge increase in our chances of developing a disease of the brain, such as dementia, Alzheimer’s and Parkinson’s disease. This latter development is thought to be due to a lack of blood flow to the brain.

We all hear about how eating a poor diet and not exercising enough can lead to a build up of plaque in the arteries around the heart, leading to a heart attack. The same thing happens to the arteries that supply the brain. As they get more blocked there is less blood flow to the brain, no it doesn’t receive all the nutrients it needs.

When we exercise the brain gets flooded with blood and nutrients, keeping it healthy. Also, exercise reduces the blocking of the arteries that supply the brain, allowing greater blood flow to keep it healthy. This increased blood flow stimulates the cells to make something called “brain-derived neurotrophic factor”, the “fertiliser for the brain” which keeps your neurons healthy.


PE makes you smarter
A study of students at a Chicago high school found evidence that exercise does indeed make you smarter. Students at the Naperville Central High School were divided into three groups: students who didn’t exercise, students who did the standard PE class (run around the oval, goof off and play a bit of sport); and the “Zero Hour group”, which would arrive early at school and do a high-intensity gym workout (running, bike, rower) at between 80 and 90 per cent of their maximum heart rate.

Researchers found that compared to the group who did no exercise the PE group had a 10 per cent improvement in exam scores while the Zero Hour group saw a -17 per cent improvement.

Higher regions of the brain, that help us come up with new ideas, be strategic, plan and control our emotions, all respond to exercise to keep them functioning at a high level.

If you exercise before you try to learn something you will learn it 20 per cent faster. Exercise is a cornerstone treatment for depression. A number of studies have shown that both aerobic and resistance training are more beneficial than medication in the treatment of depression and mood disorders.

To get the most out of your brain ensure you get at least 45 minutes’ of exercise three times per week. Make it as intense as you can handle.