Hi, Chris Wood here. What I love about my job as editor of A Rich Life is that I learn something new from my co-editors all the time.
Today, Chief Science Officer Patrick Cox will be talking about “protein pulsing,” a technique for optimizing muscle protein synthesis that I’d never heard of. Pay attention, because this is not just for weightlifters and athletes.
Editor, A Rich Life
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Protein Pulsing Is the New Steroid
By Patrick Cox, Chief Science Officer
Everyone knows that our bodies need protein as a building block for healthy living. What most people don’t know is that adjustments in how we consume protein can significantly improve strength and muscle size.
You don’t have to be an athlete or bodybuilder to engage in “protein pulsing”—anyone who wants a longer, healthier life can benefit from this technique.
A Short Primer on Muscles
Muscle strength is one of the most reliable predictors of health and life expectancy. Muscle mass, at least to a point, has clear health benefits, including an increased lifespan and cognition.
Our bodies are constantly building up and breaking down skeletal muscle tissue, which comprises 40–50% of our body mass. In healthy, active adults, about 1.2% of skeletal muscle tissue is replaced every day through a process called muscle protein synthesis (MPS).
Protein that doesn’t undergo MPS turns into glycogen and then glucose. Unless you’re in a state of caloric deficit, the protein that doesn’t become muscle can be converted to fat.
As we get older, more muscle is broken down than is built. By age 50, most people lose between 0.8 and 3% of their strength every year.
You’ve probably seen the advanced form of this condition, known as sarcopenia. People struggle to perform the most basic tasks such as standing up from a chair or picking up items from the floor.
Sarcopenia is a leading cause of functional decline and loss of independence. It contributes to metabolic syndrome and many other chronic life-ending diseases.
But you can improve MPS by controlling the way you consume protein.
(I should add that protein is a controversial topic even among scientists. The research is complex and not agreed upon by everyone. However, I’m quite confident that what I’m presenting here is correct.)
Why Eating Protein at the Wrong Time Can Make You Fat
The conversion of dietary protein into muscle is far more complex and time consuming than fat and carbohydrate digestion. For a good overview, I recommend this video.
To understand the basics of MPS, you need to know two things about this process:
- Once the MPS cycle has started, more is not better.
- Not all protein is created equal.
This is very important. Once begun, the MPS cycle runs about three to four hours, depending on the type of protein and the age, health, and lifestyle of the individual.
During this cycle, known as the refractory period, it doesn’t help to consume additional protein because it won’t convert to muscle.
Worse, because protein can’t be stored for later conversion to muscle, it will be converted to fat.
Older people’s bodies digest and use dietary protein less efficiently—so I assume that my refractory period is four hours long to avoid interrupting the cycle.
The second key point is that not all proteins are used efficiently to create muscle tissue.
The MPS cycle is initiated not by protein but by several essential amino acids (EAAs), which are abundant in animal proteins.
Of these EAAs, leucine is the most effective. Foods with high levels of leucine include meat and fish, eggs (but mostly the whites), and milk (especially whey protein supplements derived from milk).
Vegetarians and vegans often supplement their proteins with leucine. But some plant-based proteins—like nuts, beans, and oatmeal—actually have small quantities of leucine.
So if you snack on those foods between meals, you may inadvertently trigger an inefficient MPS cycle. This could interfere with protein synthesis in a subsequent meal if it is eaten during the refractory period.
That’s why I don’t eat appetizers containing leucine unless I know they will be followed immediately by the main-meal protein.
If there is too much of a delay, that fish or chicken in the main course could be converted to fat because of the shrimp cocktail you ate a half hour earlier.
(Disclaimer: I am, by the way, only guessing. We don’t know yet exactly how much leucine triggers MPS and the refractory period... or how long you can stretch out a meal without starting the MPS cycle.)
As an aside, research on the protein refractory period challenges the common hospital practice of IV or tube feeding. Optimal MPS—which is needed to repair injured muscles and connective tissues following surgery or trauma—can only be achieved through protein pulsing.
How to Optimize Protein
There are several things you can do to optimize the MPS cycle besides timing protein and leucine consumption. The big one is exercise, especially resistance training.
Resistance training can be done with barbells, dumbbells, resistance machines, elastic exercise bands, or simple bodyweight exercises.
Muscle cells that have been worked hard send signals that encourage efficient MPS. This effect seems to last for one and a half to two days.
Resistance training may even have a general whole-body effect. Bodybuilders have said for decades that heavy leg exercises make your arms stronger. Though this was often dismissed as gym science, it may be true.
Because you can only activate MPS once every three to four hours, you should make those events count. If a meal doesn’t include sufficient leucine-rich protein, I augment with a protein supplement.
Some scientists believe that people who don’t engage in strength training shouldn’t eat as much protein as those who do. Protein timing (or pulsing) is good policy, though, even if you don’t lift weights.