Lose fat and build muscle… at the same time? This is also known as body recomposition and it’s nearly every gym goer’s dream. But is it possible to do simultaneously?
First of all, what is muscle growth and how does it occur?
Muscle growth, also known as hypertrophy, refers to the development of the shape, density, shape and function of muscle cells. Muscle growth is not solely influenced by one factor but rather by a combination of factors including:
Dietary intake; including protein, carbohydrate, calorie intake and nutrient timing
Exercise quantity, frequency and type
Hormonal status; including sex hormone status and anabolic steroid use
Recovery including sleep quality and quantity
A major determinant of muscle development is training stimulus. Muscles respond to pressure and demand placed on them by heavy and intense training. They adapt to this damage and get stronger.
So is that to say that muscle growth isn’t possible when dieting?
No - while a caloric surplus might be beneficial and preferential for muscle growth, it’s not completely essential either. There are specific situations which make gaining muscle while in a caloric deficit more possible and plausible.
Those who are new to resistance training are in a prime condition to lose body fat and build muscle simultaneously. This is because muscles are the most primed for growth as training is a brand new stimulus they have never experienced. Calories from stored body fat rather than calories from nutrient intake, can be used to fuel muscle building, thus facilitating simultaneous fat loss and muscle gain once they are taking part in progressive resistance training and have adequate protein in their diet. This phenomenon is sometimes referred to as ‘newbie gains’.
Those who are overweight and obese are also in a very good positon for simultaneously losing fat and building muscle. This is because they have a large pool of energy reserves due to higher levels of body fat. Like new lifters, calories from stored body fat can be used to build muscle, even when in a caloric deficit.
This refers to people who were once experienced lifters but stopped due to reasons such as injury. This group of trainees are also in prime condition to both build muscle and lose fat due to the muscle memory effect. When previously untrained muscles undergo resistance from lifting weights, newly formed nuclei form in muscle fibres. While subsequent lack of training might lead to some loss of muscle size, the nuclei in the muscle are still present. So when someone returns to weight lifting, they are able to re-build muscle pretty quickly as new nuclei do not need to be formed. This is known as muscle memory.
Yes, even you with a few years’ experience of resistance training. It’s quite often observed that those who have been going to the gym of a number of years undergo body recomposition. This is particularly common in those who had previously trained with insufficient intensity and who had no utilised progressive overload in their training. As mentioned previously, progressive overload is one of the key factors in muscle growth. So when lifters who had never really pushed themselves to lift heavier or who had not trained consistently change their habits, they might notice that they can lose fat and gain muscle simultaneously. This can also apply to individuals who have been training but who have not been paying much attention to their nutrition and have a low, poorly-timed protein intake.
So how can I lose fat and gain muscle at the same time?
In the case of an experienced lifter or someone who is new to the gym, there are certain factors which need to be optimised in order to optimise body composition.
In order to build muscle to your best ability, you need to be following a proper training routine. Research has shown that to best optimise muscle growth of particular body parts, it is best to train them two times a week or more rather than once a week. So if you’re looking to build muscle in your lower body such as your glutes, training them at least twice a week is essential.
You should also be performing all exercises with appropriate and correct form. Most importantly, you should be applying progressive overload to your training by methods such as increasing the weight; increasing the rep range; decreasing rest time or increasing intensity.
Protein is the key macronutrient when it comes to muscle building so maintaining a high protein intake is important. A good guide for protein intake is to aim for between 1.6g-2g/kg bodyweight per day. In order to optimise muscle growth, protein intake should spread evenly throughout the day. A good rule of thumb is to aim for a serving of a high quality protein source at each meal and snack during the day. Eating a protein rich meal within 30-120 minutes of finishing a session is also important to help with muscle repair, adaptations and growth.
Rest and recovery are highly underestimated tools in muscle building. These become even more important when in a calorie deficit. A study looking at the effect of reduced sleep (5.5 hours v 8.5 hours) on fat and fat free mass found that there was a decrease in fat loss and a decrease in muscle mass in the group in which sleep was restricted. This study was highly controlled with participants being in a lab where everything including calorie intake was controlled for over 2 weeks. While both groups were in a caloric deficit, the sleep restricted group lost 0.6kg of fat while the group who got 8.5hrs of sleep lost 1.4kg of fat!
Another study looked at the effect of sleep on body composition. This study involved two groups - one group who were well rested with 7.5hrs sleep a night and one group who were sleep deprived with 5.5hrs sleep a night. Both groups were in a caloric deficit and lost the same amount of total weight. But here’s the interesting part, the sleep deprived group lost 60% more muscle mass than the well-rested group. So while the same amount of total weight was lost, the sleep deprived group lost much more muscle (which we don’t want) than the well-rested group who lost more fat (which we do want).
Simultaneous fat loss and muscle gain, AKA, body recomposition is possible. It’s much more likely in some situations but it also might apply to you if you’re an experienced lifter and you haven’t been properly pushing yourself in the gym or have not paid much attention to your nutrition. But it's important to understand, when you're trying to both simultaneously, you need to be more patient than if you were to focus on one exclusively.