Updated: Apr 10, 2020
For years we have been told that cardio is the best way to eliminate fat and lose those extra kilos. And by cardio I mean low intensity aerobic exercise, you know, jogging and jogging for hours and hours.
But is cardio actually more effective than weight training to burn fat?
The myth of cardio and the "fat burning zone"
It is believed that to lose body fat you have to burn fat during exercise. Therefore it is recommended that you do cardio with a heart rate in a specific range known as the "fat burning zone" (typically between 60-70% of your maximum heart rate).
It is assumed that if you exceed that range, fat burning would not be possible since you will use glucose instead of fat as the main source of energy.
It is true that a higher percentage of the calories burned during low intensity cardio come from fat and that by increasing the intensity (such as when training with weights or sprinting) the calories used come mainly from glucose.
However, the above ignores one fact: using fat as a source of energy during exercise has very little effect on burning total fat.
In other words, the origin of the calories used during exercise, whether glucose or fat, is irrelevant; What matters is the total calories burned. As long as you burn more than you consume (and absorb), you will burn fat.
How to burn more calories without exercising more
After training, a phenomenon known as EPOC (Excess Post-Exercise Oxygen Consumption) is triggered in which your body burns extra calories to recover. During this process your oxygen consumption is increased in order to repair the damaged muscle, synthesize proteins, remove lactic acid, among other things.
It is like a kind of maintenance work to repair the “damage” of the exercise and return your body to the state it had before training.
This extra work increases your basal metabolism by 4-10 +% for 24 hours or more after weight training. The more intense and lasting the exercise, the greater the increase. For this reason EPOC is very low in cardio cardio low intensity.
Because of these differences, it is thought that, thanks to EPOC, intense weight training has an advantage over cardio since you burn calories even when you are lying on your couch. Below are several data:
In a group of women it was found that EPOC caused an extra 60 calories expenditure during the 16 hours after exercise.
A similar result was seen in a group of men: 80 extra calories 14.5 hours after weight training.
An extra burning of 100 kcal has also been observed 24 hours after a weight session.
Likewise, one study found an increase in metabolism of 90-180 kcal 15 hours post-exercise.
Finally, an investigation found the following (impressive) results: 404 extra calories burned 24 hours after finishing the training, and another 369 calories during the next day; a 19-21% increase in basal metabolism.
These results suggest that training with weights using “large” multiarticular exercises (squats, deadlifts, bench presses, rowing, etc.) cause small increases in your metabolism that are maintained up to one day after training and, which accumulate with the step of the months, they can have an impact on fat burning in the long term.
The above is not observed with low intensity aerobic exercise, in which you only burn 5 to 35 calories after exercise.
Two factors of weight training that cardio does not have
The calories burned by EPOC may not be too many, even so, weight training provides us with two elements that cardio does not have and that are beneficial:
Maintain or increase your muscle mass. Muscle shapes your body and also extends your life.
Keep your basal metabolism. Greater metabolism = more calories burned during the day = greater ease to burn fat.
By choosing the best fat burning method, we cannot lose sight of its chronic effects on our body: which one burns more calories in the long term, maintains your muscle and preserves your metabolism?
Verdict: what we know about cardio and weight training
1- Low intensity cardio
Burn 7-9 calories / minute.
Improve your physical condition.
It does not increase your muscle mass, it can even decrease it if it is the only activity you practice.
It does not strengthen your muscles, makes them more resistant.
Do not define (tone) your muscles.
For many it is boring.
2- Weight training
Burn 7-10 calories / minute.
Preserve or increase your muscle mass when you are in a caloric deficit.
Keep your metabolism by following a calorie restricted diet
Strengthens your muscles and makes them more resistant.
Shapes (defines, tones) your muscles.
Improve your physical condition.
It's fun. There are dozens of methods and exercises that can be tried.
Are there any?
So, I don't need cardio to burn fat?
No, you do not need it.
In a world where we had to choose one of the two, weight training would succeed. It gives you more for less, cardio no.
And why not use both?
Fortunately, we don't have to choose one over the other. Doing weight training and cardio is better than just one or the other. For example:
• When comparing fat burning in two groups that trained 60 minutes 3 times per week (one only did cardio and the other combined it with weights), one study found the following:
Cardio group: they lost 3.1 kg of fat, but they also lost 2.7 kg of muscle.
Cardio group + weights: they lost 10 kg of fat and gained 1.8 kilos of muscle.
If you want to burn fat and shape your body as quickly and effectively as possible, make weight training your priority and, if you enjoy it, supplement it with cardio sessions, and if you don't like it, it is not necessary to do so.
Go to weight training as your main course, cardio as dessert.