One of many key articles of religion of contemporary sports activities diet is that your physique can solely use a specific amount of protein at a time. Opinions differ on what that quantity is. It is likely to be as little as 20 grams; it is likely to be as a lot as 40 grams, notably for older adults whose our bodies are much less delicate to the muscle-growth-stimulating results of protein. Perhaps it must be expressed relative to physique measurement, like 0.4 grams per kilogram of physique weight, moderately than as a set quantity. These particulars don’t matter right here; the purpose is that there’s a most.
The rationale that’s essential is that almost all North Individuals eat plenty of protein, however don’t unfold it evenly all through the day. A typical sample is likely to be 10 to fifteen grams at breakfast and lunch, then 65 grams or extra at dinner. That signifies that at breakfast and lunch, you’re not getting sufficient protein to max out the synthesis of latest muscle protein. At dinner, then again, you’re getting an excessive amount of, so the surplus will merely be burned for vitality. The higher answer, in response to this logic, is to easy out your protein consumption so that you simply’re getting a minimum of 20 grams (or 40 or 0.4 grams per kilogram or no matter) at every meal, including a protein-rich snack someday through the day, and maybe even one other one proper earlier than mattress.
That’s the standard knowledge. So a current examine in Cell Experiences Drugs from researchers at Maastricht College within the Netherlands, led by famous muscle physiologist Luc van Loon (whose vivid, no-nonsense recommendation I’ve written about beforehand), has generated loads of buzz. Briefly, van Loon’s new knowledge suggests there’s no higher restrict on protein in spite of everything, and that vast doses of protein—they use 100 grams within the examine, as a result of that’s about how a lot protein they figured they may eat at a barbecue with out force-feeding themselves—produce proportionately bigger will increase within the formation of latest muscle.
A Distinctive Type of Protein Examine
The examine concerned 36 volunteers break up into three teams. They every did a one-hour weight-training exercise after which instantly downed a drink containing both 0, 25, or 100 grams of protein. The protein got here from the milk of a Holstein cow that the researchers injected with a particular carbon isotope tracer. This meant that one of many amino acids within the milk had a barely totally different chemical kind than common, enabling the researchers to trace the progress of the protein drink because it was digested and integrated into new muscle proteins within the topics’ our bodies. (I as soon as interviewed one in every of van Loon’s postdocs about an earlier “glowing cow” experiment, and he described the surprising duties he needed to tackle: “My job was to speak to them, brush them, and mainly maintain them in a very good temper,” he recalled. “If the animal turns into careworn, milk manufacturing declines, so we handled them like princesses.”)
Anyway, the subsequent a part of the experiment mainly concerned sitting round for 12 hours and taking a bunch of blood samples and muscle biopsies to determine what was occurring within the topics’ muscle tissue following the exercise-protein combo. That mixture is essential: each resistance train and consuming protein increase the formation of latest muscle protein, however placing them collectively inside a window of 4 to 6 hours produces a muscle-building impact that’s higher than the sum of its components. The total suite of measurements and evaluation is extraordinarily complicated (and free to examine, in case you’re ), however a very powerful parameter is how a lot new muscle protein is being synthesized, as a result of that’s what (kind of) dictates how a lot muscle you’ll achieve over time.
There are two key issues concerning the examine. One is the time-frame: most earlier research solely monitored muscle protein synthesis for six hours or much less, so 12 hours gives a for much longer window for the consequences of an enormous protein dose to indicate up. The second is the protein dose: earlier research topped out at 45 grams, so it might have been laborious to see large variations in comparison with, say, 20 or 30 grams.
Right here’s the important thing consequence, displaying protein synthesis over the 12 hours following the exercise and protein drink. Black circles are the 100-gram group; gray circles are the 25-gram group; and white circles are the 0-gram management group:
The impact isn’t delicate: the 100-gram group is getting far more protein synthesis than the 25-gram group straight away. And the most important distinction comes after the six-hour (i.e. 360-minute) mark: by that time, the 25-gram group is again to baseline, whereas the 100-gram group nonetheless hasn’t gone again to baseline even after 12 hours. The additional protein synthesis isn’t precisely proportional—that’s, 4 occasions extra protein doesn’t provide you with 4 occasions the synthesis—but it surely’s substantial.
What the New Protein Findings Imply for Athletes
There’s a simple conclusion right here, which is that the concept of a most protein dose—a minimum of, one at 40 grams or much less—was unsuitable. You at all times wish to be cautious about chucking away an entire bunch of seemingly settled science on the premise of a single examine. However this examine appears stable, and it has recognized some clear gaps—in period and protein dose—within the earlier research that it’s overturning. So let’s assume for now that it’s appropriate. The query, then, is what it means for the way athletes ought to eat.
For sensible functions, the actual apples-to-apples comparability would have been 100 grams of protein versus 4 doses of 25 grams spaced 4 hours aside. Which sample would produce extra protein synthesis in that comparability? No one is aware of at this level. There are a bunch of different causes that I’ll be sticking with three meals a day, together with the truth that I actually get pleasure from all my meals. As an endurance athlete, I’m additionally as aware of my carbohydrate provide as I’m of protein. And even for protein and muscle-building, there are many unanswered questions—like whether or not you’d have to time your exercise round your 100-gram protein bomb. If I elevate weights within the morning then get all my protein within the night, or vice-versa, does that also work?
There are definitely people who find themselves into the one-meal-a-day factor, and for these folks this is a crucial consequence. Of their dialogue, van Loon and his colleagues notice that their findings counsel that time-restricted feeding shouldn’t essentially result in muscle loss. For me, the primary takeaway is that it’s in all probability not as essential as I as soon as thought to unfold my protein completely all through the day. That received’t change how I truly eat, as a result of getting 25 grams of protein at each single meal has at all times been extra aspiration than actuality—however a minimum of I’ll really feel much less responsible about it.
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