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Physical activity builds the brain so teachers can fill the brain

Physical activity builds the brain so teachers can fill the brain

My contribution to the governing body at St Mary’s is primarily in supporting strategy development by bringing an entrepreneurial voice to our collective thinking, and secondly through my interest in physical activity and sport.

The shock facts around the lack of physical activity are easy to come by – for example, which is the biggest killer – obesity, inactivity or smoking? The answer is that, across Europe, studies show that roughly the same number of people die prematurely as a result of inactivity as a result of smoking. In fact in a 2011 report, the Chief Medical Officer stated that “inactivity kills”.

Of course that doesn’t help much – we’re all bombarded with shocking “facts” about which we sometimes try to do something, but more often people feel powerless to behave differently as a result of this or that fact.

The programmes that I run in primary schools aim to help headteachers, teachers and all staff in a primary school to change their belief, not directly change their behaviour. In order to change behaviours successfully, you have to have the capability to behave in the new way, and in order to change your capability (for the long haul) you need to believe that this is important. Various (and extensive) bodies of work show that it is our beliefs that drive our individual decision making on a day to day basis. If I believe I can do something then generally I can.

This may explain why 79% of boys and 84% of girls aged 5-17 do not do the minimum amount of physical activity needed for their development: because not enough people believe it’s really really important. It doesn’t help that 50% of fathers (and one third of mothers) of clinically obese seven-year old children believe their child’s weight is “about right”.

I became interested in this subject as I found myself visiting primary schools up and down the country and seeing the sheer scale of the problem, both in the children but also in staff. At about this time read a book by Professor John Ratey (from Harvard University) called Spark! in which he explains the physiology of physical activity. My beliefs changed, and (I like to think) my behaviours changed accordingly.

In Spark!, Prof Ratey explains how scientists have discovered that doing exercise causes the body to produce “growth factors” that grow brain cells. He also explains how physical activity helps your brain to be more efficient, stimulated and happier. Over time, this means that people who exercise regularly tend to grow faster and sharper brains, which of course makes you feel better as well. He explains how dopamine and serotonin are released in the brain which give you a mood boost, and the whole thing feeds on itself.

Have you ever met a 7-year old who would prefer to walk when they could run? Well, this could be why, and they feel better for it.

A California study across 100,000+ children of various ages showed that the fittest children achieve at around 65th – 68th percentiles in English and Maths, while the least fit achieve at a median of around the 30th percentile. In crude grade terms that is the difference between C/D-grades and A/B-grades. (Caution: going out to get fit won’t on its own guarantee a higher grade, but it will certainly make a difference).

For those of us who are older, an interesting study at the University of Muenster in Germany showed that a group of people aged 55-65 had a 20% faster brain after running for 20 minutes on a treadmill than when they sat still for 20 minutes.

In a school context, a 20% faster brain could, mathematically and all other things being equal, translate into completing 5 hours of lessons in 4 hours. The science of sleep tells us that we should then get our full quota of sleep (7-9 hours) and not be woken up early (which would interrupt the crucial final cycle of REM sleep) to ensure the best retention of the learning. But that’s for another blog.

All of this points to the thought that moderate to vigorous exercise could be the best possible preparation in the 20 minutes before an exam, particularly as the effect can last a few hours. Imagine finishing your exam 20 minutes early for a change!

How you exercise is a whole other topic – but one study that I particularly like showed that running through a forest makes your brain work 20% faster than running through a town (the participants ran for 35 minutes if you fancy trying that one out). This one makes complete sense when you think of the brain as a muscle (it’s not, but it’s a useful analogy): running through a forest is just so much more interesting for the brain. To understand why, look at how much movement there is in a tree (which your brain will be scanning), or the way in which you have to watch your step to avoid tripping on a branch or other hazard in the forest, and compare that to jogging through town.

And finally, the money thing… a lot of studies show that fitter people earn more than unfit people (anything from 9% to 20%+ depending on the particular design of the study).

So: get fit, watch your brain work faster and ask your boss for a pay rise!


Michael Ledzion currently runs a social enterprise called Sports for Schools that brings Olympic athletes into schools to inspire children to work hard and lead a healthy life. He is also co-founder of, a platform that connects schools to club leaders and automates away the admin hassle of organising school clubs. He previously inhabited the hi-tech start up world, including as CEO of DisplayLink (a Cambridge based semiconductor company). His eldest daughter attended St Mary’s, while Michael joined the governing body in 2014.