Ask a scientist what is the best way to lose weight, and they’ll tell you cardio burns the most calories of all exercises. This is true… to a point.

In the short term cardio does burn the most calories, but long term because, as explained last week, you adapt to the exercise load it requires more work in order to see progress over time it reduces in its effectiveness.

In the long term the activity that will give you the most results is resistance training, hands down.  Most people are surprised by this, but when you get to grips with the science it becomes easier to understand. 

On average people burn around seven calories a minute doing steady state cardio.  That’s 420 calories an hour.  To burn one kilogram of fat requires a deficit of 7,700 calories.  If you were to do an hour of cardio per day every day it would take you just over eighteen days to burn off one kilo of body fat.  And most people don’t go every single day, so at best you are probably burning off one kilo of fat a month. 

Note that I say one kilogram of fat, not one kilogram of weight.  In the beginning of following a weight loss programme many people lose water first, before they lose fat. This is why the scale can be so misleading, because it indicates loss when that loss could be water, not body fat.  And unless you have access to body fat measuring equipment using your eyes can be a far better measure for progress than the scale. 

Not only that but long term cardio training leads to increased efficiency from the body; in effect your system becomes better at cardio and therefore needs less calories per minute to maintain your output.  You drop from burning seven calories a minute to four calories a minute. 

Resistance work is different.  It increases your metabolic rate, which is the rate at which you burn off calories at rest.  If, for instance, your metabolic rate is 1,500 calories per day, resistance training could pretty quickly increase this to 2,000 calories per day.  That’s an additional 500 calories every day.  And, without increasing your calories consumed that’s a 500 calorie deficit each day, which is already more than in the cardio example above.

Over time that 2,000 calories will become 2,500, and even an increase in consumption of 250 extra calories would still be a deficit of 750 calories a day, every day.  You would lose that kilo of fat in just over ten days.  That is eight days faster than the cardio example.

So how does it do this?  Resistance training stimulates muscle growth.  This doesn’t mean you explode with muscle, but over time it stimulates increased muscle fibres and density and the result is you have created a more calorie ‘expensive’ muscle than fat.  Because of this is requires more calories for the body to maintain that muscle, and because you are doing more resistance work the body prioritises maintaining the muscle you have created.  In effect this raises the requirement for calories to maintain that muscle mass, and as long as there is a calorie deficit, meaning that the amount of calories consumed is less than the number of calories required the body will utilise the excess stored fat on the body to make up the shortfall. 

The takeaway point is this; in the short term you can lose weight from cardio training.  It works best on an untrained and unadapted body because at that point calorie burning is most effective.  But that adaptation is fast, and once you have adapted to cardio its impact is minimal, at best.  Because resistance training is so variable it is harder for the body to adapt to it fully, and therefore it is superior in the long term for weight loss. 

For any queries in to how best you should workout and get the best results, please email enquiries@rkfitness.co.uk