Article updated on July 28, 2020
One of the most attractive ideas in training is to offer clients weight training to gain muscle mass. It is well known that the higher your muscle mass, the more calories you will burn while at rest.
This increase in muscle mass increases what is called the basal metabolism. Then when your basal metabolic rate is higher, it becomes easier to lose weight because you will burn more calories while resting.
What a great idea! Here is the reasoning summarized in a picture:
It is a very attractive idea. On the other hand, in practice, it does not quite give the expected results. A very well done article has been written on the subject: Prediction of resting energy expenditure from fat-free mass and fat mass, by Karl M Nelson, Roland L Weinsier, Calvin L Long, and Yves Schit.
To sum up, the article concludes that a kilogram of muscle burns about 14 Calories per day and that a kilogram of fat about 3 Calories per day.
Unfortunately, it is very little. Here is a concrete example:
Let's say that our friend Paul, who wants to lose weight, decides to train very seriously. He is very regular in his training and manages to lose 5 kg of adipose mass (fat) and to gain 5 kg of lean mass (muscle). He is really happy. He can now eat however he wants because his basal metabolism has increased.
Unfortunately, here is the reality:
- His basal metabolism has decreased by 15 Calories per day as he has lost body fat (5 kg x 3 Calories / kg / day);
- His basal metabolic rate increased by 70 Calories per day as he gained 5 kg of muscle (5 kg x 14 Calories / kg / day).
So, after months of training and hard work, Paul increased his BMR by 55 Calories per day.
To give you an idea, 55 Calories is about an apple a day.
Why is this so? This is because what has the most influence on the basal metabolism, it is not the muscles, nor the fat mass, but rather the brain and the internal organs (heart, liver, kidneys).
Note that there are, however, plenty of benefits to weight training. It's great for preventing injury, preventing loss of muscle mass with age, improving overall health, and more. The positive effects are very important.
On the other hand, it is essential to avoid making those who start physical activity dangle a mirage, namely that of a significant increase in basal metabolism by increasing muscle mass.
Other suggested articles related to this topic:
- How many calories should you burn to lose 1 kg?
- Running to lose weight?
- How to lose belly fat? The answer might surprise you
- Train with locally made and environmentally friendly weights: Altterre
Keep in mind that trained muscles consume more calories than muscles that do not exercise.
So when a person strength training, the muscles that already exist will also burn more calories.
Thus, 2 studies show that, with 30 minutes of weight training 3 times per week, the metabolism at rest increases by 105 to 120 calories per day.
Over a year, this represents the equivalent of 4 to 5 kilos of fat. It's not nothing.
A researcher, Wayne Westcott, published a very interesting article on these 2 studies.
Source
Wayne WestcottWhy The Confusion on Muscle and Metabolism.
Very good point.
Thank you for this article which sets things straight 🙂 We hear so much everything and anything in the weight rooms !!!!
I love your articles, keep it up
Thanks for the kind words!
Thanks Daniel, this article is really very interesting!
Thanks for the kind words!
Thank you very much I wonder a lot about this subject and I had stopped doing cardio because I had heard that it was useless to do it if I was doing weight training. So for a girl who hates cardio I was more than happy but I'm going to start doing a little again! 😅💪🏻
It never hurts to do it. On the other hand, there are indeed contradictory effects on muscular adaptations. What that means is that a person who wants to gain a lot of muscle mass should probably avoid cardio during this phase, in order to maximize the mass gain phase.