What macronutrient are most bodybuilders completely obsessed with? Protein, of course! Protein is made up of long chains of amino acids, the building blocks of proteins. Amino acids link with each other to form chains held together by strong peptide bonds. In total, there are twenty amino acids each differing from each other by their unique side chains. These side chains give an amino acid in one part of the chain the ability to bind with another elsewhere in the sequence to form unique protein structures that bend and fold. Because of these additional linkages proteins can take on a variety of shapes and even fold or form globular structures.
It’s hardly surprising that bodybuilders are fixated on protein. During a weight training session, you damage and tear muscle proteins and that damage must be repaired. During the repair process, satellite cells bind to the damaged muscle fibers and donate contractile elements called myofibrils, thereby increasing the size of the fibers. This process of repair is enhanced by growth factors, like insulin, growth hormone, and IGF-1, and ultimately leads to muscle hypertrophy.
For muscle repair and growth to take place, you must supply muscle fibers with the building blocks they need, specifically, amino acids from protein. At one time, experts believed that to maximize muscle growth, you needed to eat a combination of carbohydrates and protein (a ratio of about 3:1) within an hour of a workout. The thought was that there’s a post-workout anabolic window where your muscles are primed to take up the amino acids from protein and use them for muscle repair.
Based on more recent research, it’s likely that the anabolic window period applies mainly to training in a fasted state where glycogen stores are already low. Otherwise, you have more leeway. Waiting up to four hours after a workout, assuming you aren’t fasted, probably won’t significantly impact muscle growth or repair, as originally thought. Now, let’s look at WHY you need protein after a workout.
Get a Leg Up on Muscle Repair
As mentioned, weight training places stress on muscles and, when the stress is great enough, it creates microscopic tears in muscle fibers that must be repaired. It’s during the repair process that muscles grow. As discussed, muscles need the help of satellite cells and amino acids from protein to repair damage. Some amino acids your body can make but there are nine that it cannot and must get through diet. Getting a dose of protein containing a variety of amino acids gives muscles the nutritional support they need to repair and grow.
Branched chain amino acids, particularly leucine, jumpstart muscle growth after a workout. It’s leucine, along with isoleucine and valine, that activate the mTOR pathway for muscle repair and growth. The mTOR pathway is also sensitive to energy status. If you’re depleted of energy, it doesn’t turn on. So, a post-workout snack that contains protein ensures that your body