If you’re looking for information to help you build muscle, you’ve come to the right place.
At Girls Gone Strong, we believe that what is “right” for you is entirely up to you, and that the ultimate way to empower you is to give you the space to make all of the decisions you want about your life and your body, from how you choose to exercise, to how you want to look and feel in your body.
Lately, we’re noticing a growing interest among women who want to increase their muscle mass, and we couldn’t be happier! It’s exciting to see women shedding concerns about “getting bulky” and deliberately working toward muscle gain. It’s even more exciting to see women embrace the strength and confidence gained through resistance training—along with the physical changes that reflect those gains and their hard work.
Before we talk about how to build muscle, it’s important to understand a bit about the physiology behind muscle growth.
You may have heard that skeletal muscle (the type of muscle to which we’re referring when we talk about building more muscle) is made up of special types of protein, primarily actin and myosin, and their subtypes and supporting proteins. These muscle proteins, and other bodily proteins (such as enzymes, and hormones), are created and repaired from the available free amino acids floating around in the bloodstream. These free amino acids are known as the Free Amino Acid Pool and are derived from dietary protein—foods like chicken, meat, fish, eggs, whey, and dairy—but your body can also supply them by breaking down its own proteins when dietary protein intake is inadequate.
Skeletal muscle protein is in a state of constant metabolic turnover.1 This means that throughout the day, the body is constantly breaking down muscle (known as muscle protein breakdown – MPB) and rebuilding it (known as muscle protein synthesis – MPS). This process is a normal part of daily energy expenditure (commonly known as Resting Energy Expenditure – REE) and is necessary for maintaining and building strong, healthy muscle.
Muscle breakdown happens while you are in a fasted state (such as overnight, while sleeping), or when amino acids (from protein) are not readily available between meals. Muscle is also broken down during exercise. Though that might sound like a bad thing, it actually isn’t. Muscle protein synthesis is enhanced in the post-exercise period.2
Food intake slows muscle protein breakdown and initiates muscle protein synthesis; exercise augments this effect. As such, eating food (especially protein foods) and exercising, (especially strength training) are important aspects of building more muscle.2
If your goal is to develop more muscle mass and get stronger, pay attention to the following:
- An optimal muscle-building diet must contain adequate protein. Strength-training women should aim for 1.7 to 1.8 grams protein per kilogram of bodyweight each day.3For a 140-pound woman (63.6 kg), this equals approximately 115 grams of protein. More specifically, this protein should come from complete protein foods like those from animal sources (meat, dairy) and/or complete vegetarian sources like pea or hemp. The reason complete protein sources are so important is because only Essential Amino Acids which are found abundantly in complete protein, stimulate muscle protein synthesis and halt breakdown.
- The only way to build muscle is with serious strength-training.1 However, considering that you’re reading a site called Girls Gone Strong, chances are you’re probably already doing some of that. Even though the post-exercise period stimulates muscle protein synthesis, it is not enough to overcome the muscle breakdown that also occurs. This is where proper nutrition comes in. Strength training works synergistically with optimal caloric and protein intake to repair and build muscle protein, resulting in muscle hypertrophy (muscle growth).
The emphasis of this article is on nutritional considerations for muscle hypertrophy, so I will limit the discussion of resistance training here, and instead focus on the importance of dietary protein, as well as the impact of adequate calories, carbohydrates and creatine supplementation, since those are major factors that support muscle growth.
How Much Protein Does It Take?
For decades, research has been conducted to determine the ideal quantity of proteinneeded for muscle protein synthesis. Historically, the majority of this research has been performed in men. The limited science looking at differences between men and women indicates that men may have a higher protein requirement than women because they oxidize (burn) more amino acids at rest and in exercise.5 Since accurate information pertaining to women is hard to come by, you can choose to follow these guidelines exactly, or modify based on your own personal experiences.
With regards to total amount of protein, the recommendation of 1.7 to 1.8 grams of protein per kilogram of bodyweight per day, appears to apply fairly accurately to women.3,4 Some people feel that more protein than this is even more effective, but researchers have shown that the muscle-building effect tops out at 2.0 grams of protein per kilogram per day.7 The benefits of a higher intake of dietary protein extend beyond muscle hypertrophy:
- Protein is more thermogenic than carbohydrates or fats, so it may help burn more calories in a meal.6
- Protein is more satiating, so it helps control appetite, and is less likely to be stored as body fat than carbohydrates or fats when total calorie intake is not excessive.6
- Protein is an energy source for exercising muscles, not as much as carbohydrates and fats, but if carbohydrates and fats are not well-tolerated, protein can be used as fuel.6
- Protein can help prevent blood sugar spikes or dips because it converts to glucose more slowly than carbohydrates.27
Research has suggested that there is a ceiling for how much muscle protein can be synthesized per gram of protein eaten per meal – termed the “muscle full effect”.8Researchers found that 20 to 30 grams of protein in a meal is all the body can use to stimulate protein synthesis.8 However, as noted by Philips et al, 20154, these dose-response studies have been limited to lower-body resistance exercises, thus it remains unknown whether or not the absolute dose of protein required to maximally stimulate hypertrophy following upper and lower body exercises is greater than 20 to 30 grams (in other words: research isn’t perfect and does not represent every person in the population, so this “limit” per meal may not be factual).
Philips et al have found, with further whole-body resistance training research in men, that the maximum increase in protein synthesis was achieved with a protein dose of 0.25 grams of protein per kilogram of body weight per meal (for the average 190-pound guy (86.3 kg), this is 22 grams of protein).4 To account for differences among men, they suggest a dose of 0.4 grams of protein per kilogram of body weight to achieve maximum muscle growth (35 grams of protein for that 190-pound guy). For a 140-pound woman, this is 25 grams of high quality protein at a meal. Further, because protein synthesis slows down quickly after protein ingestion (within three to four hours), it is wise to consume complete protein regularly throughout the day to keep synthesis as high as possible.4 If you are vegetarian, choose a complete protein powder such as pea, rice, or hemp, or combine vegetable protein sources to obtain a complete protein profile in your meals. (You can read more about this strategy in this article all about protein.)
The Essential Amino Acid leucine, one of the branched-chain amino acids (BCAAs), found in high abundance in complete protein, is believed to be particularly important for muscle gains.9 The other two BCAAs, valine and isoleucine, don’t seem to have this same effect.10Leucine positively affects muscle protein balance by reducing protein breakdown and stimulating synthesis, similar to exercise. However, leucine’s effect on synthesis seems to be short-lived, and a longer duration of sustained protein synthesis requires that other essential amino acids, especially the remaining BCAAs, be present. Thus, leucine is the stimulator of protein synthesis, and essential amino acids are the sustainers.11 In order to achieve optimal synthesis from leucine, researchers have proposed the concept of a leucine threshold (also termed “leucine trigger”).12 It’s been shown that a two-gram dose of leucine (found in approximately 20 grams of high-quality complete protein, such as whey) is needed to achieve this effect, although variations in body size would influence how much is actually required (less for smaller people, more for larger).13 Consuming 20 to 30 grams of whey protein right after a workout is one of the best ways to get this two-gram dose of leucine. You can also choose six ounces of chicken, turkey, lean beef, flank steak, salmon, white fish, or tuna, which supply between 2.5 and 2.9 grams of leucine. Other purified protein powders, like pea protein and hemp, also provide a good amount of leucine. Further, individual BCAA supplement mixes provide at least two grams of leucine and can be consumed post workout.