Summer's here and the brambles are growing.

Today is the last day of term and parents will have to start to wonder what they're going to do with their children over the long summer holiday. If you live in Eastfield (a substantial community to the south of Scarborough) you might decide that it would be a good idea to walk with your children the 4km into town and then, perhaps, take the bus back. This way you'll all get some decent exercise and enjoy the sheer pleasure of being out in the open countryside.

But, if you choose to take the most direct, and nicest route, into town by following the bridleway that runs up the Dell and then continue on down past South Cliff Golf Club, you best not wear your shorts. Not, that is, unless you don't mind getting stung by nettles or scratched by brambles.

Overgrown path as it approaches Oliver's Mount

Of course, you could turn left when going up the Dell and join the new, replacement, bridleway that's been built by Keep Moat (the company responsible for the new Middle Deepdale development) and head across to Musham Bank roundabout where you could then take the path that runs through Blue Bell Woods and around the back of The Mere. But, then again you'd be out of luck because the path here is also overgrown by nettles and brambles,

Path from Musham Bank overgrown by brambles

The new path goes off to the left from the Deepdale bridleway

It then crosses fields as it heads to Musham Bank

Where it joins another bridleway before going down the lane to the roundabout.

We know that low levels of physical activity are beginning to cause major health problems and that the best way to avoid these problems is to incorporate physical activity into our everyday lives. The simplest way to do this is to stop being a passenger and start  getting places under our own steam. 

Politicians, health workers and public servants need to begin to take this issue much more seriously. I've no doubt that the cost of clearing a few paths will be more than covered by savings in health spending but, for reasons about which I can speculate but won't go into here, it just doesn't seem to be happening.

Claiming the Health Dividend:A summary and discussion of value for money estimates from studies of investment in walking and cycling 

Let's Get Moving

There are lots of links between physical activity and health (see references at the end).

We've recently formed a partnership of official and voluntary bodies with the aim of encouraging the people they deal with  to incorporate physical activity into their everyday lives. Quite simply this means walking or cycling for some, or part of, the journeys that you'd normally make by car or bus.

To bring attention to this we've produced a Manifesto for Physical Activity for organisations to sign up to and, so that the something actually happens as a result, make some pledges about how they'd put this commitment into practice.

We acknowledge that physically inactive lifestyles are a major cause of ill health and premature death

We resolve to encourage the people we work with to incorporate regular physical activity into their everyday lives and to work with others to help make this possible.

We believe that one of the simplest ways for people to do this is to walk, or cycle, for some, or part of, the everyday journeys they currently make.

Now it's possible to produce a list of all the diseases where the risk can be dramatically reduced - Type 2 Diabetes, heart disease, various cancers and dementia - but this doesn't explain why such a simple thing as having a regular brisk walk can have such widespread effects. 

So, I began to look at the basic science and see if there was a simple underlying cause.. 

http://dx.doi.org/10.1113%2Fjphysiol.2009.179507

What happens when you stop being active

So, here's the simple story.

Our bodies have a whole host of complex feedback mechanisms that allow them to respond to changing circumstances. That's why your heart beats faster if you start walking quickly, why your pancreas releases insulin in response to a rise in blood glucose and why you start to shiver when you get too cold. The detailed mechanisms of nerves and signalling molecules are complicated but they work. 

These feedback mechanisms have evolved over our entire evolutionary history, since before homo sapiens existed, and expect us to be physically active.

Physiology, which I once studied in rather more detail than I can now remember, is the study of the normal functioning of the body and physiologists have looked at the experiments carried out on either sedentary humans, or caged animals that can't move about much, and discovered that it's often the inactivity that's causing the problems not whatever else is being done to them. E.g. mice that have been genetically engineered to be hungry put on weight and show many of the early symptoms of diabetes. Put a wheel in their cage so that they can run around and these effects disappear. (Booth and Laye J. Physiol 2009)

So, what's normal for the mice, and what's normal for us, is to be physically active and it isn't difficult to appreciate the evolutionary reasons why this should be the case. 

‘The selective advantages of increased activity capacity are not subtle but rather are central to survival and reproduction. An animal with greater stamina has an advantage that is readily comprehensible in selective terms. It can sustain greater levels of pursuit or flight in gathering food or avoiding becoming food. It will be superior in territorial defense or invasion. It will be more successful in courtship and mating’ (Bennett & Ruben, 1979)

That's it. Your body has evolved expecting you to be physically active. If you're not, then the regulatory systems that keep your heart and circulation working properly, keep your glucose control system working properly, maintain your bone density, reduce the risk of some of your cells multiplying uncontrollably (cancer), maintain good blood flow to the brain and help wounds heal etc. can't work properly.

Earlier posts

If it were a drug gives an overview of the health benefits of becoming active

The cost of sitting around in North Yorkshire looks at the likely health impact in the County of North Yorkshire if we got more people moving.

Finally, a picture that illustrates how we've been normalising sedentary behaviour.

Done Walking, started dying