It is natural to think that exercise helps us burn energy, and the more energy we burn, the greater our weight loss results.
The fitness world has been advertising this statement, and promoting exercise as the mainstay of weight loss; it’s on every website, magazine, and the media (take a look at meal replacement and food advertisement – they always show people being active!).
Unfortunately when it comes to research into weight loss – exercise does not seem to help as much as you may think.
In a study published in Obesity 2013 – the researchers reviewed exercise interventions for a group that were clinically considered obese (Average BMI 30). They were split into two exercise and control groups.
The exercise group walked on a treadmill 5 days per week – burning either 400 or 600kcal – without changing their food intake.
Those whom exercised significantly reduced their body weight in statistical terms.
And there is the catch – “significantly reduced in statistical terms”.
In reality the average weight loss in this study was only between 3.9 – 5.2kg, for 10 months of effort.
So that’s only 0.39 to 0.52kg per month!
Well what does this mean?
This simply points out – that without calorie restriction – you cannot lose significant amounts of weight by exercise alone.
Why does this happen?
Well new research is pointing out that your body goes through changes when trying to lose weight and burn more energy.
- It improves your efficiency to exercise and also daily function – think reducing your metabolism, and burning less for the same treadmill run.
- It can increase your hunger drive – it has been proven that people often consume more energy than needed, because they have completed an exercise
“Phew I just completed my run – It will be ok to have an extra serving of cake!”
“I need the fuel to replenish my exercise – so I can have a bigger serving tonight”
(Even I am a bit of a sucker for this one!)
These changes are evident in a study in the US, that followed 14 participants from the Biggest Loser show – which highlighted that not only did all but 1 person regain their weight over the six year follow up, but their basal metabolic rate dropped by about 700kcal (meaning they were back to their pre show weight – but burning less energy per day at rest!) **worth mentioning – this study is really small and more research needs to be done to actually come to a solid conclusion – but its food for thought – pun intended!
The same increase in hunger drive and reduction to metabolism also happens with dieting too!
This doesn’t seem to favourable for the effort of exercise – but studies have found that the role of exercise in weight management is to help maintain weight loss.
Therefore once we have achieved our weight loss goal, via food and exercise changes – people whom continue to exercise don’t put weight back on!
So how can we lose weight then?
Our plan of attack becomes two fold: Firstly, focus on exercise for health and fitness benefits (you will live longer, with less chronic health issues, be more functional, and can avoid things like diabetes, cancer, heart attacks and stroke). Secondly, food behaviour and calorie control is essential in weight loss.
It is worth noting that weight loss does happen – but it’s far slower than what we want (or the media portrays) for people whom are overweight.
So let’s simply reset our goals – and make it a longer term approach.
Don’t lose focus – weight loss still occurs with exercise – just at a slower rate than you may be expecting
So using the results of the aforementioned study, exercise without any calorie restriction giving an average of 4kg weight loss over 1yr doesn’t sound like much – but keep it up for 5yrs and that’s 20kgs! Imagine what you can do with good food habits as well?
That’s worth achieving!