Should we exercise?
As our society becomes more sedentary and allows technology the licence to relieve us of the burden of light activity, we become estranged from some of the basic joys of life. Walking is increasingly foreign to the upwardly mobile human being. Who has time for enjoyable activity in this busy life? I see often now during my trivia quiz training (The Chase) that treadmills are being treated as a new invention. Listen to voice-over guy softly caress your wallet out: "The secret is in the one measly horse power, and in the non disclosure of cost".

It's still free to go outside isn't it?

How can you justify the time taken to amble around, often to accomplish a complete circuit, effectively going nowhere? As science has shown over and over, we really need a policy for regular exercise, because as I am about to show you, there's no sense in avoiding it. So what are the consequences of exercise?

Gary Taubes writes a compelling argument in his book Why we get fat and what to do about it. He delves into the assertion of the scientific canon that strongly suggests exercise causes the heavy to lose weight, and the lean to stay lean. Strangely, the evidence isn't there. What science has been able to establish is that in populations that have successfully lost weight, exercise played no part in maintenance of that loss. This is rather shocking to the person who has grown up under the assumption that exercise will cause weight loss. What is interesting is that multinational food producers peddling nutritional trash use the energy in, energy out mantra to justify their particular product in the context of a healthy "balanced" diet.


A study that surveyed 13,000 runners found that those who run the most weighed the least, but they all put on weight every year, even high volume runners. The researchers, clearly shocked by their findings went on to advocate yearly increases in running distance to maintain weight which, applied over years, would see the casual runner having to eventually run five half marathons a week. Robert Lustig in his book Fat Chance points out that when you exercise you build muscle, which increases weight.
"Good for your health but doesn't reduce your weight."

So my case for walking is looking tenuous. Hang on a bit.
Lustig lays out three solid reasons for exercise. Weight loss doesn't figure.
1. Exercise will make your cellular machine run better. You get new mitochondria which are the microscopic pieces of equipment in every cell responsible for producing the energy that makes you move like a slug or a gazelle. You can exercise more and outrun that pesky cheetah…or not. Getting new ones means you replace the old ones. Not getting new ones means poorer cellular function.
Your muscles become more adept at using glucose with exercise causing muscle building rather than fat building. This is a way of explaining what is felt by the exerciser — wellbeing, vitality and betterment.

2. Stress levels will drop and stay low for the whole day, and you get more endorphins which make you feel really good. For the uninitiated, think of an endorphin as the natural version of morphine.

3. Your liver burns energy cleaner and faster. This means energy gets from food to you faster, and it doesn't get wasted in fat storage.

A study from 2011 showed that the greater the muscle mass you create, there's a greater reduction in diabetes risk. Another study showed insulin levels were lowest in a group of elderly men who were highly physically active.

So if you want to lose weight, you have to delve into the biochemistry of eating. You need to figure out what to place in that mouth of yours, and the evidence is strong for a combination of naturally occurring whole foods, nutrient density rather than energy density, fasting regularly and regular exercise.

What I can conclude for your collective benefit is that exercise is one of the few actions that can cost you little, and yet yields richly in longevity and excellence of body function. Yes, it is true that you burn a large amount of calories in your sleep and lounging in front of the TV (called resting energy expenditure) but with no health improvement value.

My stroke of genius in exercise strategy was to buy a house 3.4km from work. I walk to work briskly most work days. It is the time of day that I can either focus on the day to come, or completely tune out to it. I can take in 32 minutes of a fusion of nature and urbanisation, or as is my habit of late, listen to RNZ's Morning Report, with the promise that I may hear that the Greens have succeeded in redeeming another curse word for our collective benefit. Maybe a better word for Marama to reclaim for the nation is Exercise. Yes for some a curse word, but so empowering for all humans. What I have noticed is that such a regular habit of walking did nothing to prevent a gradual shift in weight from the late 80s into the mid 90s (kilograms). I actually gained weight walking more briskly over the three months of a weight loss challenge a few years ago. Exercise was the strategy, although not much more than I was doing before, I was startled to see gain. Perhaps I caused my quads and gluteals to bulk up in a minimalist way, which could explain weight gain? The lesson is, the scientifically reasoned and tested purpose of exercise is for wellbeing only.

Arnold Schwarzenegger's top competition weight was 113kg. His body mass index would have been 32. This is classified as obese. Muscle weighs more than fat, so weight is a poor indicator of metabolic health.

As a purveyor of exercise, I usually design a strategy for bringing function back in a deficient bodily part. As a qualified advocate for the physical health of the general population, it is my responsibility to zoom out of the specifics from time to time to help the whole person restore the optimum workings of their machine, with such fascinating facts as I have shared here. Your response is to now evaluate your exercise level and really question if you are investing in the long term with regular moderately intense exercise.

Greg Bell is a physiotherapist practising at Bell Physiotherapy.