At a convention in 2012, Luc van Loon was presenting some thrilling information from a newly published study. After a heroic analysis effort that took 2.5 years and 500,000 euros, he and his colleagues had managed to shepherd a big group of frail, aged topics by means of a six-month strength-training program. Those who had taken a each day protein complement managed to pack on a formidable 2.9 kilos of latest muscle. Success! Old individuals might be sturdy!
But van Loon, an “extraordinary professor” (his precise title) of train physiology and vitamin at Maastricht University within the Netherlands, wasn’t celebrating. On his telephone was a photograph one in every of his college students had simply despatched him of a giant plate stacked excessive with bulging cubes of uncooked beef. In whole, there have been 3.1 kilos of beef—a graphic visualization of the muscle misplaced in only one week by topics of a bed-rest study the scholar had simply accomplished.
“I usually put this in more obscene language,” van Loon says, “but you can mess up a lot more in one week than you can improve in six months of training.”
Over the previous decade and a half of, van Loon has emerged as one of many world’s most rigorous and revolutionary researchers on the intricacies of how we construct muscle. But he has now come to consider that, from a well being perspective, how we lose muscle is no less than as necessary. At a conference in Rhode Island final month, hosted by the New England chapter of the American College of Sports Medicine, van Loon laid out the important thing classes he and different researchers within the discipline have gleaned. For anybody who seeks to push their limits, or who plans to get previous, listed below are the highlights.
You Are What You Just Ate
If you actually wish to perceive how protein contributes to new muscle, you want to have the ability to comply with the person parts—amino acids—on their journey inside your physique. Starting in 2009, van Loon and his colleagues developed a way that concerned infusing 40,000 euros’ value of amino acids, specifically “labeled” utilizing a uncommon and trackable isotope, right into a cow. Then they milked the cow and, 24 hours later, slaughtered it. The end result: milk and beef that may be tracked with painstaking precision because it progresses from an individual’s mouth to their biceps by taking frequent samples of blood and biopsied muscle tissue within the hours after a meal.
In one of the resulting studies, the researchers discovered that substantial quantities of the “glowing cow” protein was integrated into muscle mass inside simply 2 hours of ingesting it. As the examine’s title proclaims, you might be, fairly actually, what you simply ate. Just over 50 p.c of the protein made it into the topics’ circulation inside 5 hours, with the remainder presumably taken up by tissues within the intestine or not absorbed. During the identical interval, 11 p.c of the ingested protein was integrated into new muscle.
Overall, van Loon factors out, we break down and rebuild 1 to 2 p.c of our muscle every day, that means that you simply utterly rebuild your self each 2 to a few months. This is a message, van Loon hopes, that may persuade individuals to assume a little bit extra rigorously about what they put of their mouths.
If You Exercise First, You’re More of What You Just Ate
We usually consider amino acids because the “building blocks” of muscle. That’s true, however the amino acids derived from protein really play a twin position in muscle progress: In addition to being a supply of uncooked supplies, protein acts as a signaling molecule, triggering the expansion of latest muscle. One amino acid particularly, leucine, appears to be essentially the most potent anabolic signaler, however you want all of the amino acids collectively to successfully construct muscle.
There are a bunch of subtleties right here, just like the optimum dose of protein. In wholesome adults, a dose of about 0.25 grams of protein per kilogram of physique weight appears to max out the protein synthesis sign from a given meal. That’s about 20 grams of protein should you weigh 175 kilos. So it is sensible to hit that focus on 3 or 4 and even 5 occasions a day.
That’s why van Loon and his workforce determined to experiment with a pre-bedtime dose of protein to see if they might increase muscle synthesis as you sleep. Their preliminary proof-of-principle examine concerned snaking a tube down the nostril and into the stomachs of their topics and flushing in 40 grams of protein whereas they slept. It labored—and van Loon, to his bemusement, quickly began getting calls from sports activities coaches asking the place they might get nasogastric tubes. (You can simply eat the protein earlier than you fall asleep, he defined to them.)
But the easiest way to enhance protein’s muscle-signaling capability is straightforward: Exercise earlier than you eat, and your muscle mass change into extra delicate to protein’s indicators. “You can’t study food without exercise, and you can’t study exercise without food,” van Loon says. “There’s a synergy between them.”
If You’re Inactive, You’re Less of What You Just Ate
Unfortunately, there are additionally components that make your muscle mass much less delicate to protein signaling. Getting older is one in every of them, which is why older adults appear to wish a bigger dose of 0.4 grams of protein per kilogram of physique weight, moderately than 0.25, to max out their charges of protein synthesis.
But is it actually age that causes this “anabolic resistance”? Or is it merely a consequence of our unlucky behavior of changing into much less bodily energetic as we age? Van Loon’s bed-rest examine piqued his curiosity within the fast and devastating results of inactivity, notably in hospital settings, the place persons are usually confined to mattress for 5 to seven days. According to the “catabolic crisis” mannequin of getting old, we don’t lose our muscle mass at a gentle and predictable price. Instead, a lot of the loss takes place throughout quick durations of time—per week in mattress after a fall or a knee substitute, say—throughout which we lose huge quantities of muscle that we by no means absolutely get again.
Van Loon advocates some easy fixes—like by no means, ever feed somebody in a hospital mattress until it’s completely vital. Make them stand up, and ideally make them shuffle down the hallway to get meals. Same for watching TV. Even this tiny quantity of muscle contraction, he says, will improve muscle synthesis when the affected person eats. Similarly, because you don’t eat as a lot whenever you’re in mattress, the proportion of protein within the meal needs to be increased to make sure ample muscle synthesis indicators.
Of course, some individuals actually can’t get away from bed—so van Loon did some wild-sounding experiments. In 1, he immobilized one leg of his volunteers with a forged for 5 days, then drilled a gap within the forged to use neuromuscular electrical stimulation (NMES) to half of of these volunteers. The immobilization brought about a 3.5 p.c discount within the cross-sectional space of the quadriceps; twice-daily electrical stimulation prevented this loss.
In another study, van Loon tried the method on precise comatose sufferers within the intensive care unit of a hospital. Biopsies confirmed that these sufferers have been seeing a 20 to 30 p.c discount within the measurement of their muscle fibers throughout their hospital stays. “Basically the people are melting in front of your face,” he says. So van Loon zapped 1 leg however not the opposite with NMES twice a day for per week—and once more warded off atrophy. The method is nowhere close to nearly as good as even essentially the most primary train, he says, but it surely seems to be higher than nothing.
Chew Your Food
Okay, this 1 doesn’t actually rank up there as an Eternal Law of Muscle. But it’s cool. In one of the “glowing cow” studies, van Loon and his colleagues in contrast floor beef to steak. The floor beef was absorbed extra rapidly, with 61 p.c of the tracer amino acid within the floor beef showing within the bloodstream inside six hours versus simply 49 p.c for the steak.
How important that is stays a bit unclear (charges of muscle protein synthesis weren’t considerably totally different within the examine), but it surely’s value noting—notably as a result of we are likely to get much less good at chewing our meals as we become old. In truth, van Loon says, research within the 1960s discovered that individuals who retained extra of their very own tooth tended to have extra muscle. Bizarrely, physique place additionally issues: When you eat mendacity down, you decelerate protein digestion and certain cut back the synthesis of latest muscle protein.
So, as van Loon informed the convention in Rhode Island, the general physique of analysis boils down to 1 easy message: Your mum was proper. Eat 3 protein-rich meals a day, get loads of train, and—I’m not going to warn you once more!—sit up and chew your rattling meals. With your mouth closed.
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