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:
The emphasis of this article is on nutritional considerations for muscle hypertrophy, so I'll 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, because those are major factors that support muscle growth.
For decades, research has been conducted to determine the ideal quantity of protein needed 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 Because 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 body weight 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:
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.”8 Researchers 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.10 Leucine 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 larger13.
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.
The practical application of this research on protein intake is the following:
The body stimulates protein synthesis as a response to strength training for up to 48 hours, but muscle breakdown also lasts for 24 hours.2 Following exercise, there is a two-day window in which the body can build muscle with optimal nutrition, and one day during which muscle breakdown is greatest. Resistance training primes the muscle to take up amino acids and promote muscle tissue growth, but this process must overcome protein breakdown with proper food intake. Thus, the 24-hour post-exercise period is one of the most important times to consume protein and adequate calories.
When the goal is hypertrophy, consuming protein before a resistance training workout may not offer any additional benefit to taking in protein soon after exercise is complete.8 Some researchers even speculate that pre-workout protein may actually blunt the post-workout boost in protein synthesis due to an overlap in the muscle-full effect. Thus, timing protein one hour before and one hour after a full hour of training might be OK, but having protein immediately before, throughout, and right after exercise may be excessive and unnecessary.4
Schoenfeld et al conducted a meta-analysis looking at the timing of protein intake in relation to exercise. In this, they stated total protein was a better predictor of hypertrophy than timing, but the post-exercise period is still the best time to rehydrate fluids, replenish muscle glycogen, and repair the muscle with protein (three R’s).14
Overall, contrary to popular advice you may have heard in the past, there might not be an “anabolic window” of opportunity for optimal muscle protein synthesis following a workout.4 What seems to be more important is adequate total daily protein, and essential amino acid with leucine intake before or after your workout, but not necessarily at both times.
I’ve written before that calories are those tiny creatures that live in your closet and sew your clothes a little bit tighter each night. I joke, of course, but the truth is that increasing calorie intake tends to confuse and scare some women — particularly women who are accustomed to dieting and restricting calories and are suddenly advised to eat more to achieve a positive caloric balance in order to build muscle. Fat gain is a legitimate concern for many women who are shifting toward a new and different physique goal such as hypertrophy.
It is normal to gain some body fat along with muscle during this process, but that effect can be minimized with the proper training and nutrition strategies in place.
Adequate caloric intake has a profound effect on the ability to build muscle.
During periods of excessive caloric deficit, the body favors protein breakdown over synthesis. You may be in excessive caloric deficit if you’re experiencing some or all of the following:
You may be wondering how it’s possible for women who compete in figure or fitness competitions to look incredibly muscular though they are definitely in a caloric deficit. What you’re seeing in many cases is the result of a massive loss of body fat and preservation of some of the muscle that they previously built. During this phase, they are not focused on building new muscle. In fact, they will lose some muscle mass (and strength) in this process, but they formed a great foundation of muscle before dieting for competition.
It's common for male and female physique and bodybuilding competitors to go through various training seasons within a year, determined by their competitions. In their off-season, they may focus on "bulking" (adding muscle as well as some body fat). It's not sustainable for most competitors to remain that lean throughout the year, so they eat and train in a way that allows them to maximize muscle gain, and then lose a lot of body fat for competition.
Being in caloric balance — eating just enough energy to sustain exercise and daily metabolic processes — is also not optimal for muscle growth. During periods of energy balance, the constant breakdown of proteins in the body (not just muscle proteins) is replenished by skeletal muscle because the caloric input is still not enough to support both metabolic needs and muscle growth.15 Although resistance training counteracts some of these losses, the anabolic response of muscle is still blunted, which compromises muscle growth.4
Alternatively, a positive energy balance is a potent stimulator of muscle hypertrophy, even in the absence of resistance training, provided that the intake of dietary protein is adequate.16 While actively pursuing muscle gains, some body fat may accumulate. This is to be expected, but it should not be excessive. This is common among bodybuilders, both male and female. They will “bulk up” between competitions — to gain the maximum amount of muscle, despite a little bit of fat gain. They then diet down for 12 to 16 weeks to lose fat and reveal all that newly developed muscle.
Combining resistance training with a surplus of calories is the best way to build the most muscle and strength. If you want to minimize fat gain during this process, and are an experienced trainee, you don’t need to increase your calories excessively to elicit a hypertrophic response. It seems that people who have been training for a while need less of a caloric surplus to gain muscle than untrained people.17 If gaining muscle is your goal, it’s important to remember that you may not be lean and “shredded” during this time, however, fluctuations in body fat are normal and healthy for all women. Many women cannot sustain extreme leanness year-round.
How Do You Know If You’re Eating the Right Amount of Calories?
You may be wondering, “Well, how many calories do I need to eat to build muscle? What’s the magic number?” There is no one-size-fits-all answer to this question. Everyone’s metabolism is a different, and individual energy needs will vary from person to person. My recent article about calorie counting as well as Laura Schoenfeld’s article about under-eating both offer some guidance in determining your calorie needs.
Contrary to popular belief, there is no essential carbohydrate requirement. In fact, your body can make all the glucose (the breakdown product of carbs) you need from amino acids and fatty acids through a process called gluconeogenesis. Nevertheless, it does use large amounts of carbohydrate for exercise energy expenditure. Carbohydrates are stored in your muscle tissue in the form of glycogen, which your muscles breakdown during exercise to create ATP/energy.21
The majority of the ATP production in your body (about 80 percent) comes from glycogen breakdown, not protein or fat oxidation.18 When your body is low in glycogen, such as when you follow a low-carbohydrate or ketogenic diet, you may feel very lethargic and weak when you exercise. Some people adapt to this low-carb state as their bodies switch to using fat as a fuel source (stored in the muscle tissue as triglycerides), and energy production from dietary protein is upregulated.
However, unless someone has an intolerance to carbohydrates, which occurs in people with diabetes and metabolic syndrome, most fit and healthy people benefit from carbs in the diet to maximize exercise and athletic performance.
When it comes to hypertrophy, low-carb diets still allow the body to build muscle. During my time at UCONN working toward my PhD, we conducted a strength training study in men that compared a low-fat diet to a low-carb ketogenic diet (a diet containing less than 50 grams of carbs per day) with resistance training.19 Each subject in this study was required to drink a protein drink providing 20 grams of whey protein following their resistance training workout, which they performed three times a week (See Table 1 below for training example). The resistance workout involved compound, full-body, and isolation movements, and was challenging for each participant.
After 12 weeks, we found that the low-carb diet resulted in just as much muscle gain (assessed by DEXA) as the low-fat diet and had a significantly greater loss of body fat. The difference in body fat between the groups may have been due to total protein intake (the low-carb group ingested far more daily protein than the low-fat group) and average age of the groups (the low-carb group had younger participants in it). Overall, we showed that a low-carb diet did not negatively impact the ability to gain muscle. A study like this has not been done in women, so the implications for females are not known.
Carbohydrate is also highly regarded for muscle gain due to its association with the hormone insulin. This hormone blunts protein breakdown and is considered an important stimulator of muscle hypertrophy, especially in the post-workout period. However, insulin and carbohydrates do not stimulate protein synthesis.20 We cannot discount that slowing muscle breakdown in the presence of synthesis (stimulated by amino acids) will result in greater muscle gain.
Given that carbohydrate foods are one of the major drivers of insulin secretion, it’s often pushed in post-workout nutrition, especially if you exercise in a fasted, low-insulin state. Carbohydrates also replenish muscle glycogen used during exercise. Some people mistakenly believe that if some insulin is good to stop protein breakdown and refill glycogen stores, then spiking insulin with a maximum amount of carbohydrates must be even better. That’s #BroScience, and we don’t advise doing it.
There is an insulin threshold to prevent muscle breakdown and push glucose into muscle to replenish glycogen. The impact of insulin on net muscle protein balance has been shown to plateau at three to four times fasting levels.22 A normal meal following a workout can achieve this effect one to two hours after consumption, and levels remain elevated for three to six hours (or longer) depending on the size of the meal and the person’s individual response.
For example, researchers found that a meal containing 75 grams of carbohydrate, 37 grams of protein, and 17 grams of fat raised insulin concentrations threefold over fasting conditions within a half hour after consumption, and increased to fivefold after one hour. At the five-hour mark, levels remained double those seen during fasting.23
If you eat a big meal before your workout, your insulin levels will stay high. Hence, the need to rapidly reverse muscle protein breakdown with insulin stimulation is only necessary if you don’t eat before exercise.21
Another aspect about insulin that many people fail to remember is that whey protein (from protein shakes and dairy) stimulates insulin secretion. Therefore, dairy or whey protein alone can promote synthesis and prevent breakdown.
The rationale for still including carbohydrate in your post workout meal is to help replenish glycogen used during training. Carbs provide the glucose, which gets stored in your muscle as glycogen, and insulin directs glucose there.
How much carbohydrate should you consume daily? According to Schoenfeld, in studies conducted mostly in men, only a moderate amount of dietary carbohydrate is needed for enhancing exercise performance and producing optimal hypertrophy.21 It is unclear exactly how much carbohydrate intake is needed for maximizing exercise-induced muscle hypertrophy, but three grams per kilogram per day is a reasonable starting point.21 For a 140-pound woman, this is about 190 grams of carbohydrate per day (about 763 calories) from whole food sources like grains, potatoes and sweet potatoes, vegetables, fruits, and residual carbohydrates in protein foods. For women in a caloric surplus with the goal of hypertrophy, this seems reasonable.
However, as my mentor Jeff Volek PhD, RD and I wrote in a peer-reviewed paper in 2006, women do not store as much glycogen in muscle as men in response to the same dose of dietary carbohydrate, and it is unclear in women how dietary carbohydrate influences muscle hypertrophy.24 Also, some women (especially those who have competed in bodybuilding or figure competitions in the past) have elevated insulin responses to carbohydrates, so they may require less carbohydrate in their diet.24 Each woman’s needs are different, and she should listen to her own body to find her ideal nutritional breakdown.
The menstrual cycle can also influence the body’s responses to dietary macronutrients. In the first 14 days of a woman’s cycle, her body will use and respond more favorably to dietary carbs. In the latter 14 days, her body uses more dietary fats.25 As such, using your cycle as a guide for tailoring your carbohydrate intake may be something to consider.
Overall, some women may do better with less than three grams of carbs per kilogram per day during some times of the month, or just in general. Listen to your body and experiment with what works best for you.
Finally, let’s talk about creatine, because this supplement is very much associated with strength training. I wrote an article about creatine for women, and I strongly encourage you to read it, especially if you are unfamiliar with this supplement.
While there is quite a lot of research on creatine, there have been just a few studies examining creatine use in women. The available research to date shows that it can help a woman build strength, which is often attributed to increased muscle mass.
In a recent study in women, researchers looked at the effects of creatine supplementation on muscle strength and body composition with strength training. Nineteen sedentary women were assigned to a creatine group (10) or a placebo group (9). They consumed 20 grams per day of creatine for five days and then tapered down to five grams of creatine or placebo for 10 weeks.26
The scientists found that after 10 weeks, increases in 1RM (one-rep max) leg press, leg extension, and squat were 20 to 25 percent greater in the creatine group than the placebo group. More importantly, they saw that fat-free mass (muscle and non-fat tissues in the body) increased to a greater degree in the creatine group.26 Overall, in untrained women, creatine supplementation enhanced strength and body composition responses to resistance training. Thus, creatine is a prudent addition to your diet if you are looking to maximize strength and muscle gains.
By now you have a better understanding on how your body builds muscle and which dietary nutrients help maximize your body’s response to strength training. For best results, in addition to performing resistance training workouts, follow these four nutrition guidelines:
I want to emphasize one more thing: while these goal-specific nutrition strategies will support muscle building, the most important aspect of this process is resistance training. You can’t build muscle without applying external resistance.
So go forth, lift heavy, eat well, and watch those muscles grow!
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