Are You Getting Enough Protein? Here’s What the Science Says

As an athlete, you may need more protein than you think to build and maintain muscle.

While the nutrition industry tends to toggle between carbohydrates and fats as the dietary “villain” of the moment, protein generally remains a nutritional hero. (Spoiler: You need all three for a healthy, balanced diet). But if your goal is to build or maintain muscle, power, strength, or performance, you definitely want to ensure an adequate protein intake each day. Eating one large portion of chicken at dinner won’t cut it—your muscles require protein at least four times each day to recover and rebuild. To help you do that, here’s what the research and science suggest about optimal protein intake.

Why is Protein So Important?

Any type of rigorous exercise—and specifically strength training—induces a continuous breakdown of muscle fibers. That’s actually how we build and grow the muscle tissue: Lifting creates microtears in the muscle fibers and causes the subsequent rebuilding of those fibers for lean body mass maintenance or achieving muscle and strength gains. Our bodies turn to protein—specifically amino acids which are the building blocks of protein—for this muscle growth and tissue repair.

So right off the bat, athletes require more protein than the average person. The recommended dietary allowance (RDA) for protein is only 0.8 to 1 gram per kilogram of body weight per day for the average person. 

If you’re thinking that sounds a lot lower than you expected, that’s because it is. The RDA is set as the amount of protein that is needed by the general population in order to prevent protein insufficiency. Preventing insufficiency and ensuring optimal intake are two very different things, and any expert worth their weight would rarely advise simply aiming to prevent insufficiency.

How Much Protein Do Athletes Need?

There are countless opinions out there, but science is the best place to turn. Resistance training studies were among the first to begin exploring the relationship between increased exercise and increased protein needs. Unsurprisingly, a recent meta-analysis published in the British Journal of Sports Medicine, confirms that in order to gain muscle mass and strength, you need to take in closer to 1.6 grams of protein per kilogram of body weight per day. This translates to around 130 grams/day for a 180-pound athlete, 115 grams for a 160-pound athlete, 100 grams for a 140-pound athlete, and 90 grams for a 120-pound athlete. 

But it’s not as simple as just aiming for a certain number each day. Let’s use the analogy of driving a car across the country as an example: You will need a lot of gas, but you can’t fill your tank once and expect to drive 3,000+ miles. You will need to stop to refuel along the way. Protein intake is similar.

In order to maximize muscle recovery and strength gains, research suggests you need to feed your body protein-rich foods at least four times each day rather than larger doses one to two times per day. That means it’s best to include protein-rich foods at all meals and at least one snack whenever maintaining or building lean body mass is a priority for you.

You also want to build up to that higher protein intake, especially if you’re not consuming that much protein now. Think of it like lifting: You wouldn’t try to deadlift 200 pounds without training first. You’d start with deadlifting 50 pounds, and then build up the strength to increase the weight. The same goes for protein. You don’t want to suddenly slam your system with over 100 grams of protein if you have only been consuming around 50 grams. You’ll want to slowly increase your intake each day to train your body to utilize the protein to the best of your ability.

It sounds like a lot—yes, but the good news is that there are a wide array of foods that are high in protein and taste great, too. Since most people will be aiming for at least 80+ grams of protein per day, let’s think about protein in 20-gram blocks. 

Here’s how much you need to eat of these popular foods to get 20g of protein:

Of course, you do not need to get all of your protein from any one source at each meal or snack, so feel free to mix and match the above as you move and eat throughout your day. For example, two eggs paired with a 1/2 cup of beans or 5 ounces of Greek yogurt with 2 tablespoons of hemp seeds will net you at least 20 grams of protein.

There are a few other important considerations when speaking about adequate protein intake. One is that in order for your resistance training and protein eating to pay off in terms of muscle and strength gains, you need to be taking in adequate energy (calories) each day. 

The American College of Sports Medicine Joint Position Statement for Nutrition and Athletic Performance is clear that when an athlete is in low-energy availability—either because they’re trying to cut weight, achieve weight loss, or there’s a mismatch in needs versus intake—the requirement for protein increases and ability to build and maintain muscle is impaired. So take care to fuel your body and your workouts adequately as you also pay attention to adequate protein intake.

If you happen to be in an overall calorie deficit and also want to maintain muscle during that period, you will want to increase your protein intake to closer to 2.0 grams of protein per kilogram per day. But continuing with this pattern for too long may set your overall nutritional intake too low, and you’ll risk losing muscle as well as compromising training, strength, immune function, and much more. Studies show varied responses to low-energy availability in women versus men, whereas as few as four days of low intake (defined as 19 to 25 kcal/kg of lean body mass per day) in women and three weeks of low intake in men leads to an inadequate ability for the body to support all physiological function for optimal health.

Another consideration for sufficient protein intake is that, as we age, absolute protein needs have been shown to increase, thus the above protein goal and numbers may fall a bit short for older athletes. Research is currently ongoing on this important topic, but we do know that Masters athletes looking to maintain or gain lean body mass may need to ingest closer to 30 or even 40 grams of protein four times daily, as protein utilization rates decrease with age (thus we need to eat more absolute grams of protein to meet daily repair and recovery needs).

How to Achieve Your Protein Needs

We always recommend a food-first approach, since foods contain many beneficial nutrients and compounds in addition to protein. But many busy athletes find it tricky to consistently take in adequate protein four times per day and may benefit from adding a supplement from time to time, or even once per day.

If you do supplement your diet with protein shakes, powder, and drinks, remember that they are not regulated, which means they might include not-so-good-for-you ingredients that are not listed on the label.

One easy way to verify a supplement is free of contaminants or undesired ingredients is to look for the “NSF” or “USP” certification on package labels. There are many options to choose from, and luckily, you can choose whether you would like to include a milk-based (whey or casein) or plant-based (generally from pea, hemp, soy, or a combination of the three) based on your personal preference.

Regarding protein type, while you may have heard that including specific amino acids, mainly branched-chain amino acids (BCAAs and specifically Leucine), is needed in order to stimulate maximum muscle protein synthesis, the most recent research concludes that as long as you are taking in at least 20 to 30 grams of protein post-workout and at each meal with one snack to total four times per day, you do not need to focus specifically on BCAAs.

Still, both milk-based proteins (whey and casein) are touted as being high in BCAAs and demonstrate high nitrogen retention and bioavailability (meaning a higher percentage of the total protein you eat will be put to good use) in studies on protein supplementation in resistance-training athletes.

Additionally, vegetarian protein sources, including the widely-studied soy protein, can be included in order to effectively reach your protein needs. If choosing a soy-based or plant-based protein, it will contain lower amounts of the essential amino acid methionine, but you can easily get adequate amounts of that amino acid by eating grains and vegetables and/or meat and dairy, so either way, you’ll be covered.

The Bottom Line

You, in fact, do need more protein than your less active friends (and than the recommended daily allowance), but for most people, the benefits of increasing your protein intake drop off after about 1.6 grams of protein/kg of body weight per day. So as long as you include protein-rich foods four times per day aiming for between 1.2 to 1.6 grams of protein/kg of body weight, you don’t have to be overly concerned about getting any one particular source or even all essential amino acids at each meal. 

Simply continue your resistance training at least two to three times per week and choose a wide range of foods that you enjoy, ensuring that the combination of foods you choose includes at least 20 grams (or possibly 30 to 40 grams, pending age or during times of low energy availability), and you will be able to reach your strength, power, and increased muscle mass goals.

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