We all want to achieve a lean and muscular physique. To do this, we obviously need to build muscle and burn fat. We’ve been told that it’s impossible to do both at the same time. ”You need to be in a calorie surplus to build muscle!” But less is true. Trying to build muscle while losing fat is not impossible, but it may not always be the most effective way to approach your fitness goals. You’ll read why in this blog post.
What Happens In A Caloric Deficit?
When you’re in a caloric deficit, you’re consuming fewer calories than your body needs. This puts you in a catabolic state, which means your body is breaking down internal reserves for energy. The primary source your body taps into when it’s in a calorie deficit is body fat.
After all, our body gains fat (if you force it to) so it can use it in times of food scarcity. But body fat is not the only thing your body breaks down when you’re in a calorie deficit. Research shows that muscle protein breakdown also significantly increases.
As you’ve probably read in this post about protein intake, the human body builds muscle by synthesizing new muscle proteins. This is referred to as ”Protein Synthesis”. Our bodies also break down muscle proteins: ”Protein Breakdown”. If the number of muscle proteins your body synthesizes exceeds the number of muscle proteins your body breaks down, you’ve built muscle.
So, if you increase the number of muscle proteins you build and decrease the number of muscle proteins you break down, you gain more muscle. Unfortunately, maintaining a calorie deficit does the exact the opposite. Research shows protein synthesis rates drop and protein breakdown rates increase when you’re consuming fewer calories than your body needs.
Is It Possible To Gain Muscle Then?
This simply means your body will build less muscle when you’re in a caloric deficit. But if it goes to the point where the number of muscle proteins you break down is greater than the number of muscle proteins you synthesize, you will actually lose muscle.
For most people, this won’t be the case. We know through multiple studies that when inexperienced lifters train effectively, they gain muscle faster than experienced lifters. So even if protein breakdown increases and protein synthesis goes down, they will still be able to synthesize more muscle proteins than their body breaks down.
Even if the diet is quite aggressive, some can see great results. If we look at a study by the University of McMaster, we can see that the inexperienced volunteers on average gained 2 lbs. of muscle and burned 10 lbs. of fat while maintaining a caloric deficit of 40% in 4 weeks. So if you’re just starting off with training and have some body fat to lose, you likely will build muscle in a calorie deficit. Yes, while losing fat. As long as your workouts are effective for stimulating muscle growth.
But this doesn’t change the fact that inexperienced lifters likely are able to build even more muscle if they’re not in a calorie deficit because of the catabolic environment.
The closer you are to your genetic limit, the harder it is to gain muscle. Fitness researchers have put together guidelines to the amount of muscle you can build naturally over time. Although they slightly disagree about how much muscle you can build naturally, they all agree that muscle growth significantly decreases as you get more advanced.
That’s why an experienced lifter may not be able to build muscle in a calorie deficit. The number of muscle proteins he/she will synthesize won’t be greater than the number of muscle proteins broken down.
This is the main reason why advanced lifters go into ”bulking” phases and swear by them.
How Most Can Build Muscle and Lose Fat
Muscle growth is an adaptive response. By putting greater amounts of tension on your muscles over time, they’ll have to adapt. The human body does this by increasing muscle size and strength.
This helps explain why there’s research showing progressive muscle tension is important for muscle growth. There are several ways to do this. The most obvious way is by slowly increasing the amount of weight you’re lifting over time.
When trying to build muscle, you’ll often hear that you need to maintain a small calorie deficit, so your body has more nutrients to work with. From a short-term, ”muscle-building” point of view, this is true. But to burn a significant amount of fat you would need to stay in a deficit for a fairly long time (because you burn less fat on a small deficit). This is not favorable for several reasons.
But then again you have to be careful because an approach that’s too aggressive can decrease the amount of muscle you’re building. Based on these three studies, losing 0.5-1% of total body weight per week is a good range for those looking to improve body composition. This generally can be achieved by maintaining a calorie deficit of roughly 20-25%. Like in this study, in which athletes lost an average of 1.2 lbs per week by maintaining a deficit of 24%.
Protein plays a vital role in muscle preservation when you’re in a calorie deficit. There are plenty of studies supporting this. Next to decreasing muscle breakdown, research shows that a high protein intake also increases the amount of fat you lose (in the same calorie deficit). So a high-protein intake helps with both sides of the equation.
A 2017 systematic review indicates that consuming at least 0.7g/lb. (1.6g/kg) of body weight is able to maximize muscle growth. If you want to err on the safe side of things and make use of the satiating effects of protein, you can feel free to consume more protein in a day.
As you can see, building muscle and burning fat at the same time isn’t impossible. It just gets harder as you get closer to your genetic limit. As you advance, you might find that you’re not able to build a significant amount of muscle during your ”cut”.
The good news is that most people are not even close to their genetic limit and, therefore, will be able to effectively improve body composition.
If you are interested in learning more about maximizing your muscular potential, check out my new eBook “The Art & Science of Muscle Growth.” This book translates the currently available scientific data regarding muscle growth in “Simple English”, so everyone can start implementing an evidence-based approach to training and nutrition.