In the innocent old days, people looking to grow their muscles would suck back mugs filled with raw eggs, sometimes laced with heavy cream. (Think Sylvester Stallone as Rocky Balboa, or Arnold Schwarzenegger.) In recent years, however, more efficient means of getting protein have emerged in the form of myriad supplements, bars and powders. These products allegedly help do what the eggs of yesteryear managed: get you ripped.
Cans of protein powder can cost between $30 and $100, and they come with amazing claims: you'll quickly increase the mass and size of your muscles and gain the strength and power to work even harder. Gym denizens buy into these claims. According to an industry analysis last year, the market for sports nutrition products is expected to grow 62 percent by 2018, reaching $7.8 billion.
But do these products actually do anything special to help gym-goers bulk up? In a word: no. There's one thing that will make you huge, and it's not sports supplements.
How muscles grow
First, a note on how muscles grow and how that relates to protein in your diet. Your muscles are basically organs made up of long bundles of fibers. They can expand or shrink depending on several factors: your genes, age, hormones, what you eat, and how much you work out.
"The motions of exercise turn on the machinery in muscle to make it grow, and growth is a function of turning on more protein synthesis in cells so that the cells expand or grow," explained Nathan LeBrasseur, who studies muscle and metabolism at the Mayo Clinic.
Exercise switches on a signaling pathway in your muscles, telling the cells to build more protein. So you're expanding the protein in the cells when you exercise. This process is called "hypertrophy." (It’s easy to remember because it’s the opposite of atrophy, or the wasting away and shrinking of muscles.) How all this relates to dietary protein is rather complex, said LeBrasseur, but can be made simple by this explanation: "It takes protein to make protein."
Protein is made up of 20 amino acids. (There are 11 your body produces, and nine "essential amino acids" you need to get through your diet.) Muscle cells are predominantly made up of protein. To do the work of building them, you need to provide your body with amino acids through protein-rich meals.
Do protein supplements really help?
If you search the literature on protein supplements and muscle gain, you find many conflicting studies that either show these products make a difference or that they don't do anything at all.
To figure out where the truth is, the researchers behind this meta-analysis brought together the results of a bunch of the best studies on the effect of protein supplementation and muscle growth. They found that protein supplements only led to a little extra muscle gain (about one kilogram or two pounds) in younger people and had even less of an impact on people over 50.
Stuart Phillips, a professor in the department of kinesiology at McMaster University, said of the study, "Actually getting to the gym and working out is what gives you the gains. Protein powders just help, but only a little." In other words, what made the biggest difference for people was the exercise.
"If you don't get into the gym, no supplement will ever help you gain mass," he added, "and if you're getting into the gym, then supplements are the icing on the cake, not the cake itself."
So what's the best way to get huge?
The best science, according to Phillips, points to this equation: lift weights, lift them to fatigue or as close as possible, and consume a protein-rich diet (i.e., about a quarter of your energy from protein) to maintain your weight plus a little extra. "In truth, the process is simple but can be made to be over-complicated by those looking to make money," he said. "You will see varying degrees of muscle-mass gain that are likely determined to a large extent by your genes. You can’t outrun what Mom and Dad gave you."
Steroids will, of course, help you build muscle fast, but they also come with a range of side effects that run from the embarrassing (breast growth, acne) to dangerous (liver cancer, high blood pressure, and heart problems, including heart attack). So, Phillips said, "People want to fluff up this explanation, but the basic principle is lift, eat, sleep, repeat."
Sports nutritionist and trainer Matt Fitzgerald also recommended the "time under load" equation when working out: "This means you need to lift heavy and you need to lift a lot (i.e., do plenty of sets and reps)."
Because this approach tires the muscles, he said, people need to rest 48 hours or so between workouts. "For this reason, bodybuilders tend to break the body down into separate zones and focus on one at a time: chest and arms one day, legs the next day, and back and shoulders the day after that."
What about other sources of protein?
Nobody has ever tested, head-to-head, the performance of protein supplements and protein-rich foods. But all the exercise and nutrition gurus we spoke to think that dietary protein probably performs just as well as or better than supplements, and all said they would opt for nutrient- and fiber-rich whole foods. They also recommended balancing the efficiency of a quick hit of protein in the form of prepackaged proteins against the potential harms caused by eating the added sugars, chemicals, and salt that these products often contain.
In his book Racing Weight, Fitzgerald suggests precooking proteins for the week (ie., chicken breasts), preparing larger meals so that you have leftovers for the next day, and stocking up on foods such as Greek yogurt and cottage cheese. This way you have protein sources on hand when you need them.
"To maximize muscle growth," Fitzgerald said, "you need to maintain at least a moderately high-protein diet and consume protein within an hour after each workout. These requirements can be met with or without protein supplements."