Taking just a whey isolate and/or concentrate post-workout may not be enough to maximize muscle growth. Both speeding up the digestion rate of whey via whey hydrolysates, and providing a very slow-digesting protein, such as casein, can push muscle gains further after workouts, as research continues to show.
Hydrolyzed Whey Protein
Whey protein is already the fastest-digesting protein that you can consume. But that doesn’t mean that it can’t be configured to do so even faster. The only way to make whey protein a quicker-digesting protein is to predigest it in the lab. To do this, the long protein chains of whey undergo a process called hydrolysis. This breaks apart the bonds that hold the amino acids that make up the whey protein chain, creating small protein fragments known as peptides. This means your digestive system has less work to do breaking apart the protein chains, allowing it to be absorbed and delivered to your muscles at a much quicker rate. After workouts, this speed is critical to get muscle growth started asap.
Whey Protein Isolate/Concentrate
There’s no debating the fact that whey protein is one of the most critical proteins for muscle growth. It’s rich in branched-chain amino acids (BCAAs) and beneficial peptides, and it digests at a rapid rate. The major difference between a whey isolate and a whey concentrate is their production. Whey protein isolate undergoes more processing than whey concentrate, which creates a protein powder that is about 90% protein or higher. Whey concentrate is typically only about 80% protein. While a whey isolate is a purer protein than a whey concentrate, the gentler processing used to create a concentrate typically leaves more of the beneficial whey peptide fractions intact. This means that both have their benefits.
While having whey hydrolysates and whey isolates and/or concentrates post-workout are important to quickly kick-start muscle growth, these faster proteins keep muscle protein synthesis increased only for a short period. To prolong the amount of time that protein synthesis is turned on, it’s important to also have a protein that digests at a slow and steady state. Casein protein is the perfect choice for this job, as it essentially forms clumps of protein in the stomach that are digested one at a time over the course of many hours. Look for casein in the form of caseinates—such as calcium, sodium, or potassium caseinate— which mix easiest in fluids, or for micellar casein, which is less soluble in fluids but digests even slower than caseinates.
Mix and Match
This table lists several protein powders that contain at least two forms of these proteins for optimal recovery and growth after workouts.