Moving on to the next category—casein.
Several studies show that eating protein alone or with carbs before exercising increases muscle protein synthesis.8
One of these studies found a positive muscle building response after consuming 20 grams of whey protein before a workout.9 According to this study, to reap the benefits of a pre-workout protein shake, you need around 30 grams to do the trick. So it’s very common for weight lifters and bodybuilders to get their pre-workout protein in the form of whey.
Most people believe that since whey digests faster than casein its must be better than casein before a workout.
But that’s not actually true. While whey produces a more significant spike in muscle protein synthesis, it doesn’t enhance this muscle protein synthesis for as long as casein does. So over time, the total increase in muscle protein synthesis between whey and casein tends to be the same. Meaning, in that regard, one isn’t better than the other.
But with that said, whey is not as good as casein at preventing muscle protein breakdown.10 This makes casein the better pre-workout protein for gaining strength and muscle when compared to whey.
And we can see this being confirmed in a study that looked at the changes in body fat and muscle mass in overweight police officers. They followed a calorie-deficit diet with a high protein intake while also lifting weights throughout the week. They divided the cops into groups. One group had a casein protein product. In contrast, the other group had whey.
And after 12 weeks, the casein group gained, on average, almost 9 pounds of lean muscle mass while the whey group gained only 4 and a half pounds.11
The casein group was also able to increase their chest, shoulder, and leg strength by 59 percent throughout the study.
In comparison, the whey protein group only increased their strength by 29 percent, which is a significant difference.12
The researchers believe that this significant difference in body composition and strength is most likely due to improved nitrogen retention and overall anticatabolic effects caused by the casein’s peptide component.13
To put it simply, casein was better at preventing muscle protein breakdown, making it a superior choice pre-workout since your workout will drastically increase muscle protein breakdown. So, maybe consider having some casein before your workout and combining it with something like oatmeal and skim milk.