We all know that sleep is important. It gives the body time to heal and recover from physical and mental exertion, and even repair damaged DNA. But did you know that your sleep cycle may be a key factor in determining both muscle gains AND losses?
According to a study review published in Frontiers in Nutrition (regarding Snijders’ 2015 seminal study), overnight sleep may be a unique nutritional window for boosting or reducing muscle gains. So, what’s “the scoop” that’s helping make the difference? Casein protein.
Casein is a protein that is slower to be digested and absorbed by the body (it’s estimated to release Amino Acids for the body for about a 7-hour window), making it ideal for longer periods of “fasting” and still maintaining appropriate blood protein/amino levels. As we sleep, we essentially fast and cease taking in nutrients for the body. Due to this, typically towards the end of our sleep cycles our blood protein/amino levels drop and our bodies (to balance this back out) may begin relying on other sources of protein within the body. Without that balance, our muscles can neither repair themselves, nor grow.
In Snijders’ 2015 study, his team put a small sample group of 44 participants on a 12-week lifting program. Half of the participants were given a nightly Casein rich, pre-sleep protein shake containing about 30g of Casein and 15g of carbs. The other half was the control group, only receiving an energy-free drink prior to sleep. After the 12 weeks, both groups saw an increase in their 1-rep max for the squat, as well as larger quads. However, the results of the “protein before bed” group were able to gain significantly more muscle strength and mass.
It was also noted that pre-sleep protein intake did NOT have any negative effects on sleeping habits, nor did it effect any muscle-building effects of protein taken in during breakfast the next day. On another occasion, evidence also suggested that pre-sleep protein may help increase the body’s natural rate of fat burning the following day; it is believed that Casein may reduces the body’s insulin response to subsequent meals which forces your body to use more fat as a source of energy
So, where can you find Casein? In just about every dairy product on the market (cream, yogurt, cottage cheese and even Ice Cream can be sources). Casein and whey are the 2 primary protein types in cow’s milk, according to a Livestrong article referencing Healthline. Dairy-alternative milk sources, however, will not contain Casein. One word of caution however, if you’ve had challenges digesting dairy in the past, Casein (like Whey) may not be for you.
Don’t feel like eating your weight in cheese right before bed? Casein is also available as a powdered supplement much like whey protein varieties.
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