It is a simple law of the universe that in order to gain weight, we need to consume more calories than we use, and in order to lose weight, the opposite is true. It may therefore seem counterintuitive to some to suggest that we can grow muscle and anabolic (tissue building) process, whilst also having catabolic (breakdown of tissue) processes occurring at the same time. This led many to believe that you need to be eating an excessive amount of calories to support muscle growth, as you will hopefully now see, this is not entirely true.
Let’s start with muscle building. In order to build muscle we need to force an adaptation through resistance training, focusing on the right intensity and volume to cause muscle growth. We then need to provide enough protein, which contains the right amounts and types of amino acids (the building blocks of muscle) to support the creation of the new proteins that then make up our newer, hopefully bigger muscle.
This process of stimulating the creation of new muscle proteins is known as muscle protein synthesis, this requires energy (as do all anabolic processes) to take place. So to recap:
Weight training + Amino Acids + Energy = Muscle
It may seem at this point that we do indeed need to provide an increased amount of energy to support muscle growth, but this is where body fat comes in. It is a common misconception that when we think about the calories our body uses for energy, we think of it as entirely from the food we are eating at the time, forgetting that energy also exists in storage forms such as glycogen and our main energy reserve, body fat. What is important here is that we draw on these storage reserves to provide energy on a calorie deficit, this is why we lose body fat to make up for our lack of calorie intake from foods!
Even on a calorie deficit, we will lose weight overall (thus maintaining the laws of the energy conservation), our body can still create new muscle tissue, as long as there’s enough protein, the correct training stimulus and enough energy reserves (body fat and glycogen) to support anabolic muscle-building processes. It is therefore fully possible that in people who have excess body fat, they can indeed grow muscle and lose fat at the same time!
Unfortunately for leaner people, without an abundance of excess energy stores, it is likely that they will need extra calorie intake from food to support muscle growth. This might lead to an often necessary increase in body fat to ensure enough energy is being provided, especially if they want to grow muscle quickly. However, an excessive increase in body fat through hard ‘bulking’ is not often required, it is typically unnecessary, and can actually be detrimental to muscle growth in the long run.
Paul Rimmer (BSc, MSc, PhD).
