If you’re looking to build muscle, you’re going to need to become familiar with protein, as these crucial amino acids will eventually form the foundations on which new muscles are constructed. For many, protein powders remain a convenient and useful accompaniment to the gym, as these products typically allow athletes to take big doses of protein without the associated calories. The array of choice can sometimes be overwhelming – these days, bodybuilders can choose between a range of protein powders, from the popular (like whey or casein) to the obscure (like vegan-friendly pea or hemp proteins).
Today, we’re going to take a look at two of the most popular forms of protein available: the milk-based whey, and casein protein powders. We’ll take a look at the benefits each kind brings to the table, their relative drawbacks, and which one is ultimately preferable given your situation. Enjoy!
We get whey as a by-product of the cheese production process. It is actually the thin layer of liquid that is left over after cheese is formed, which can then be dried to form a concentrated powder of protein.
Whey is fast-digesting, which means that it only spends a comparably short amount of time in the digestive system before it is metabolised. In terms of your protein intake, this means that you should expect to receive a sharp burst of amino acids in a relatively short period of time – 40 minutes after consuming whey protein, the levels of amino acids in the bloodstream should reach a high point. Within 60 minutes, blood amino acid levels should then drop back to normal, as the protein is synthesised or oxidised. Source
Compared to casein protein, whey protein is able to offer more rapidly usable amino acids, but needs to be topped up more regularly in order for athletes to enjoy the maximum benefits. It also contains higher levels of leucine than casein protein, an amino acid that remains vital for protein synthesis.
Casein is also a by-product of cheese-making, although this form of protein is actually taken from the curds (the solid matter that is separated from milk to make cheese). Producers can use curds to make the cheese directly, or can alternatively dehydrate and powder the solids to make a casein protein powder supplement.
To an extent, casein’s natural tendency to congeal and form a gelatinous mass explains its usefulness as a form of protein. This more solid form of protein is digested far slower than whey, which results in athletes receiving a steady release of amino acids over a longer period of time – the blood amino acid levels tend to peak 3-4 hours after consuming. Source
Although it needs to be consumed less frequently than whey protein, the “peak” associated with casein protein is far lower. Put simply, casein comes with a far weaker protein dose than its main rival, although it can offer a form that breaks down far less quickly and dramatically.
Some studies have taken the interesting step of directly comparing the two. In one study, researchers gave 30 grams of either whey or casein protein to a group of athletes after 10 hours of fasting, before measuring the anabolic effect it had on their bodies over a 7 hour period. Whey protein was found to cause a sharp increase in protein synthesis within one hour, although the effects had mostly disappeared by the 4-hour mark. Casein protein was found to leave athletes with a larger positive protein balance after 7 hours, although it failed to ever reach the protein synthesis heights achieved by the whey powder. Source
Ultimately, whey protein offers athletes a more extreme dose that is useful if they are willing to remain topped up throughout the day. This is because whey protein is uniquely able to offer more dramatically high levels of blood amino acids and protein synthesis. Conversely, those who prefer to take one protein shake in the morning and be done for the day may prefer the long-lasting effects of casein protein. Have a think about your routines, your appetite for stomaching repeated dosages of protein powders, and your workout goals before selecting your choice.
This should ultimately be the takeaway of the above study. Sensible athletes can utilise the relative effects of both to achieve what they are looking for – for example, it might make sense to take casein protein at the start of a day filled with exercise, before topping up with whey protein before more intensive strength-training sessions.
Many studies have asked athletes to take a mixture of both casein and whey protein together, with this combined mix often helping consumers to perform better than other comparable carbohydrate mixes. Source, Source, Source
For those of us looking to avoid obsessing over supplements, a combination of fast-acting whey and slow-acting casein protein in one drink, could hit all cylinders in the quickest and easiest way possible!