Build Muscle and Burn Fat at the Same Time
We're Putting an end to the eternal debate and clearing things up by explaining why and how you can build muscle and burn fat at the same time.
Burning Fat Isn’t the Same as Losing Weight
The Web is full of myths when it comes to this topic. Is it even possible to build muscles and burn fat at the same time? Most discussions argue that there are two completely different and contradicting metabolic states (catabolism and anabolism) that are incompatible with each other. You need to have a surplus of calories in order to build muscles and a deficit of calories to burn fat. And there we have the crux of the problem: burning fat isn’t the same as losing weight. You can still gain weight and burn fat at the same time!
Building Muscles and Losing Fat Are Physiological Processes that Occur Simultaneously
The body is in a state of constant growth or breakdown. Certain building blocks are broken down (catabolism) in order to generate energy and then be restored again (anabolism). Both states combined, create the body’s metabolism.
Metabolism is driven by enzymes. Depending on a person’s metabolic state, the process may either be inhibited or promoted, but never completely stopped. Exercise and diet, for example, can influence this metabolic state, enabling the body to maintain its metabolism and optimally coordinate the development of muscle and fat loss.
Intermittent Fasting Is the Best Diet to Build Muscle and Burn Fat All at Once
Intermittent fasting is a diet that optimises when food should be eaten and when exercise should be done to achieve maximum results when it comes to losing fat and building muscle. It is also based on the phenomenon of exercising on an empty stomach, which has two main advantages:
Low insulin resistance promotes muscle building and reduces the risk of cancer. To put it simply: Insulin is released the moment we eat something. The hormone ensures that the food’s nutrients are absorbed. Sugar enters the liver and muscles in the form of glucose and is stored there so that it can be used as a source of energy at a later point in time. The problem is that if we eat too often and too much, our bodies become more resistant to insulin. Regular fasting also allows less insulin to be released over a long period of time, making our bodies more sensitive to the hormone. This risk of heart disease, diabetes, and cancer is reduced too (Stolzenberg-Solomon et al., 2005; Halbergetal, 1985; Jeukendrup, 2005).
Higher growth hormone production encourages muscle building and fat burning: The growth hormone “somatropin”—which has a major impact on muscle growth, bone formation, and fat loss—is released while strength training and sleeping (Welle et al. 1996).
“Leangains 16/8” – 16 Hours of Fasting, 8 Hours of Eating
Many different types of interval fasting exist. The “Leangains 16/8” protocol looks particularly promising. This diet does not allow you to consume anything except water for 16 hours. Then there is a period of 8 hours where you are allowed to eat.
Nothing should be consumed for 16 hours. Water, tea, and black coffee – or anything that is calorie-free and does not affect metabolism – are excluded, however. Breakdown processes take over during this fasting phase, and fat is burnt at the fastest rate because the body turns to its own fat reserves to generate energy.
As a result, it is best to exercise at the end of the fasting phase and not eat anything before working out. Studies have found that if you eat a meal that is high in carbohydrates right before exercising, fat burning will be hindered by up to 35% (Jeukendrup 2005).
After exercising, you should then eat three meals in a period of eight hours. The largest meal should be consumed first with the two small meals spread out over the remaining time. The positive effect of combining “eating after a long period of fasting” with a previously completed “workout” is that the maximum amount of growth hormones is released at the same time! Eating releases a short burst of insulin while exercising simultaneously increases testosterone levels. Both hormones are essential for building muscle and burning fat. The simultaneous release of both hormones enhances their individual effect.
Example schedule: Leangains 16/8
12:00 noon: Exercise
1:00 p.m.: 50% kcal intake
4:00 p.m.: 25% kcal intake
8:00 p.m.: 25% kcal intake
8:00 p.m. – 12:00 midnight: Fasting period
You can shift this period to fit personal circumstances, work, school, sleeping patterns, eating habits, etc. For example:
10:00 a.m. – 6:00 p.m.: Eating window
6:00 p.m. – 10:00 a.m.: Fasting period
Strength Training Is a Must for Building Muscle
Exercise and nutrition go hand in hand. Muscles can’t be built without physical activity. This can only happen if the appropriate stimuli are present. Muscle development is the body’s way of adapting in order to protect itself. Muscles are intentionally damaged during exercise and then only gradually rebuilt during the regeneration phase, provided the necessary nutrients (proteins) are available. Strength training should ideally look like this:
Short and intense
6–12 reps per set
Max. muscle training (exercise until muscle failure)
Intermittent fasting is suitable for you if...
exercising on an empty stomach causes no issues for you.
your goal is to gain muscle and lose fat.
you are disciplined.
you want to try something new.
Target Attainment Depends on the Caloric Balance
All in all, it can be said that it is very possible to build muscle and lose fat at the same time. These are physiological processes that are either helped or hindered in the body depending on the metabolic state. Whether we see tangible results right away or not is another question.
In terms of its practical benefits, it’s really not that interesting if both occur “simultaneously” however. It is more important for you to pay attention to a specific time period in which as much muscle mass as possible can be gained, thereby reducing fat percentage. By specifically timing when you eat and fast, you can either promote and/or prevent the state you want to have depending on the situation. The balance at the end of a predetermined period is key for determining whether our goal is achieved or not.
If your objective is to gain muscle and reduce fat, it usually takes weeks, months, or even years before you see results. They are long-term processes that do not occur within a few hours or days, meaning the term “simultaneous” is relative in this context. In fact, if you time when you eat and fast well and prolong the time frame for achieving your goal, you can absolutely build muscle and lose fat “simultaneously.”
Halberg, N., Henriksen, M., Söderhamn, N., Stallknecht, B., Ploug, T., Schjerling, P., & Dela, F. (2005). Effect of intermittent fasting and refeeding on insulin action in healthy men. Journal of applied physiology (Bethesda, Md. : 1985), 99(6), 2128–2136. https://doi.org/10.1152/japplphysiol.00683.2005
Jeukendrup, A. E. (2005). Fettverbrennung und körperliche Aktivität. Deutsche Zeitschrift für Sportmedizin, 56(9), 337-338.
Stolzenberg-Solomon, R. Z., Graubard, B. I., Chari, S., Limburg, P., Taylor, P. R., Virtamo, J., & Albanes, D. (2005). Insulin, glucose, insulin resistance, and pancreatic cancer in male smokers. JAMA, 294(22), 2872–2878. https://doi.org/10.1001/jama.294.22.2872
Welle, S., Thornton, C., Statt, M., & McHenry, B. (1996). Growth hormone increases muscle mass and strength but does not rejuvenate myofibrillar protein synthesis in healthy subjects over 60 years old. The Journal of clinical endocrinology and metabolism, 81(9), 3239–3243. https://doi.org/10.1210/jcem.81.9.8784075