If you want to grow muscles and get stronger, you need to understand the basics. About 80% of the muscle is composed of protein (water excluded). If you want to increase muscles growth and get stronger you will need to somehow create extra muscle protein. Exercise alone will not do the trick.
Whether you create muscle protein (muscle protein synthesis, MPS) is dependent of two factors. First the amount of protein breakdown. The body can for instance break down protein for energy usage. Second the amount of protein synthesis. This is the production of protein. Variation in muscle protein is therefore the outcome of protein synthesis minus protein breakdown.
If you want to create a positive balance in muscle protein, you should either decrease the protein breakdown or increase the protein synthesis.
If you do nothing, protein breakdown exceeds protein syntheses resulting in a loss of muscle protein. If you want to create a positive balance in muscle protein, you should either decrease the protein breakdown or increase the protein synthesis. Some think strength training does the job. But that is often not the case. Although strength training increases protein synthesis, it also increases protein breakdown. The latter is not that strange: a strength workout costs energy, and protein breakdown is a way to use protein as an energy source.
The protein balance after exercise is less negative than when doing nothing. But even with exercise, there is still a negative muscle protein balance, with a higher protein breakdown than protein synthesis. The only way to seriously increase muscle protein synthesis to a positive balance is to eat protein. This should not be a surprise. If you want to add a garden house to your home, you need to buy new bricks. If you don’t buy new bricks but still want to build the garden house, your only option is to break down another part of your home to use those bricks.
So, if you don’t want to break down another structure in your body for relocation, you need to consume proteins. Just like exercise, nutrition proteins increase protein syntheses by a ~ 3-fold. In contrast to exercise, consuming proteins also decreases protein breakdown. So, the positive effect of eating chicken nuggets on muscle growth is bigger then the effect of exercise.
Don’t get me wrong. Strength training still has a positive effect. Strength training is like opening up the possibility for proteins to do their job. The combination of strength training and sufficient protein intake is by far the fastest way to increase muscle mass and strength.
Let’s get practical. Both for strength athletes who want to grow strong muscles and for endurance athlete who want to preserve their muscles. Having not enough proteins in your body is literally killing your muscles by increasing protein breakdown. Therefore, two things are important: quantity and timing.
Quantity. Consume 1,2 to 2,0 gram protein per kilogram body weight, per day. If you weigh 80 kilos, that is about 100 to 160 gram proteins per day. For those of you who eat a lot of animal products: you are probably already close to that number. For those who don’t, seriously consider adding extra proteins to your diet.
Timing. Not consuming proteins for longer than 4 hours seems to increase protein breakdown. Therefore, distribute your protein intake over 4-5 servings and use “fast” proteins like whey-protein when possible. Use “slow” long-lasting proteins like casein-protein before sleeping to make sure your body has enough building blocks throughout the whole night.