If you find it hard to lose weight – here’s why it’s not your fault 8



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If you go to the gym or walk the dog to burn as many kilojoules as you can, you’ll be disappointed to learn that your nervous system is sabotaging your efforts.

Researchers reporting in the Cell Press journal Current Biology have found that our nervous systems are remarkably good at changing the way we move so that we expend the least amount of energy possible. Our bodies are good at being fuel efficient, and we are hard wired to be lazy cheats.

The findings, which were made by studying the energetic costs of walking, likely apply to most of our movements, the researchers say.

“We found that people readily change the way they walk – including characteristics of their gait that have been established with millions of steps over the course of their lifetime – to save quite small amounts of energy,” says Max Donelan of Simon Fraser University in Canada. “This is completely consistent with the sense that most of us have that we prefer to do things in the least effortful way, like when we choose the shortest walking path, or choose to sit rather than stand. Here we have provided a physiological basis for this laziness by demonstrating that even within a well-rehearsed movement like walking, the nervous system subconsciously monitors energy use and continuously re-optimises movement patterns in a constant quest to move as cheaply as possible”.

There is a bright side to this, lead author Jessica Selinger adds: “Sensing and optimising energy use that quickly and accurately is an impressive feat on the part of the nervous system. You have to be smart to be that lazy!”

The research team wanted to understand why people move the way they do, and it’s partly a question of evolution and learning. But, the researchers wanted to know, to what extent can our bodies adapt movement based on real-time physiological inputs? In other words do our bodies cheat as we exercise, so that it’s difficult for us to work as hard as we want to to reach those fitness goals, and burn those kilojoules?

To find out, the researchers asked people to walk while they wore a robotic exoskeleton. This allowed the researchers to discourage people from walking in their usual way by making it more costly to walk normally than to walk some other way.

This allowed the researchers to test whether people can sense and optimise the cost associated with their movements in real time. And it turns out we can. We are hard wired to be lazy!

The experiment revealed that people adapt their step frequency to converge on a new energetic optimum very quickly – within minutes. What’s more, people do this even when the energy savings is quite small: less than five per cent.

So if your exercise plan just isn’t working, it may not be your fault, your body is hard wired to be lazy!


Have you tried exercise programs and failed? Have you found an exercise routine that works really well for you? How to you keep fit and stay in shape? Share your fitness tips with us.

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  1. What a lot of tosh. I lost 15 kilos 4 years ago and have kept it off. Not hard. Restricted my calories to 1200 a day and walked on my treadmill for 1/2 hour 5 days a week. I did plateau after I lost 9 kilos. Hopped on the internet and did my research. I then changed my routine (stopped walking but kept to 1200 calories) and that started me losing again. Lost 15 kilos in 7 months and have kept it off by watching how much I eat and regular exercise. It is simple unless you have a medical condition. If you eat more than your body needs you will put on weight. If you eat less you will lose weight.

  2. Exercise has lots of other benefits, especially walking outside – improves mental health and Vitamin D levels for example.

  3. As many of you will know l adopted a clean eating lifestyle many months ago. In the beghining l found it easy to stick to and it gave me more than enough energy to walk on a regular basis. Fast forward a few months and l feel lam back to square one, as l resort to eating to cope with stress. I have not walked for some time. Recently l was advised by my GP to take up swimming which l plan on doing when its a little warmer. I love swimming and it not only strips the weight of me, but also acts as a form of stress relief.Cheers.

  4. I have type 2 Diabetes started walking on my treadmill half hour after each main meal stopped eating sugary things soft drinks and have lost in 3 months 10kgs though I have stagnated now I have to give up on a few carbs I think and introduce more salads as the weather is getting a bit warmer

  5. I have been very overweight for 38 years and I hate it I have underactive thyroids type 2 diabetes which is so out of control depression I am always hungry nothing works for me I just live with it but I am so miserable I want to go for walks but feel so drained I give up my hubby is retiring very soon hopefully we can do walks together eat healthier maybe not being alone might just help

  6. What a cop-out!
    Energy in (food); energy out (exercise).
    If more out than in, you will lose weight.
    Personal choice; personal consequence; personal responsibility.

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