What Is Hypertrophy? Maximize Your Muscle Growth

Ever wonder what is hypertrophy? You already know that your diet and training program plays a crucial role, but what’s the mechanism behind this process? Are there any ways to make it happen faster? 

Muscle hypertrophy causes an increase in the volume of muscle cells. It depends on several factors, including sex, genetics, training, and nutrition. 

Note that hypertrophy isn’t the same as hyperplasia. The latter is characterized by an increase in the number of cells and may indicate an underlying condition. 

The primary way to stimulate hypertrophy is heavy lifting. A study published in the British Journal of Sports Medicine indicates that resistance training may induce muscle growth in as little as four months. 

However, muscles grow at different rates in response to strength training. That’s why you need a workout plan that targets all muscle groups and helps correct imbalances in size and strength. 

Your age, diet, and hormone levels as well as the type of exercise matter too. Endurance training, for example, targets different muscle fibers than heavy lifting. 

Today we’ll discuss the mechanism behind hypertrophy, the different types of muscle fibers, and how to stimulate muscle growth. With this information, you’ll find it easier to create a diet and training plan that meets your individual needs. 

Let’s dive in! 

What Is Hypertrophy and How Does It Occur? 

Hypertrophy is the enlargement of a tissue or organ. Unlike hyperplasia, this process doesn’t involve the multiplication of cells. Instead, it results from an increase in cell size. 

Similarly, muscle hypertrophy is an increase in the size of individual muscle fibers, according to a research paper published by the University of New Mexico.

It occurs in response to progressive overload, which involves applying varying levels of stress to your muscles, such as when starting a new training program or lifting heavier weights. 

Progressive overload forces your muscles to grow in order to keep up with the demands of exercise. That’s why it’s recommended to gradually increase the weight used or the number of sets, among other factors. 

Your muscle fibers have satellite cells on the outer surface. These cells are dormant under normal conditions and have the role to facilitate muscle growth and repair. They only become active in response to trauma or injury. 

Strength training causes micro-tears in muscles, which in turn, activates the satellite cells. These cells begin to multiply, and the new cells travel to the affected area where they fuse to muscle fibers. As a result, your muscles recover from training and increase in size. 

Hypertrophy is also influenced by growth factors, cortisol and testosterone levels, immune function, and more. Nutrition plays a role too. Building muscle requires an energy surplus, meaning that you must take in more calories than you burn. 

Journal of Frontiers in Nutrition

A 2019 review published in the journal Frontiers in Nutrition recommends a daily energy surplus of 1,500 to 2,000 kilojoules or 358 to 478 calories. Furthermore, it’s important to determine your macros (the amount of protein, carbs, and fats) and meet your nutritional needs. 

As the researchers note, protein intake has a direct impact on hypertrophy. This nutrient makes up about 20 percent of skeletal muscle. Try to get at least 1.6 grams of protein per kilogram of body weight daily for mass and strength gains. 

How Does Strength Training Influence Muscle Growth?

Resistance training activates the satellite cells, leading to hypertrophy. But that’s not all. 

Heavy lifting also increases protein synthesis, which further accelerates muscle growth. Additionally, it influences several signaling pathways that influence hypertrophy, points out a research paper featured in IntechOpen. 

The extent to which these pathways are activated depends on age, sex, workout intensity, and the types of muscle fibers used.

Strength training and high-intensity interval training promote hypertrophy and may increase maximal force output. Endurance training, on the other hand, doesn’t have these effects, according to the above review. 

Resistance training enhances the size of type II (fast-twitch) muscle fibers and leads to mass gains. These muscle fibers are used for sprinting, heavy lifting, and other high-intensity, short-duration activities.

Compared to type I (slow-twitch) fibers, they’re less resistant to fatigue but can generate more force. 

Fast-twitch fibers begin to take over when the slow-twitch fibers become fatigued, notes the American Council on Exercise. Both strength and power training recruit and activate these muscle fibers, which are responsible for muscle size and definition. 

Slow-Twitch vs. Fast-Twitch Muscle Fibers 

Different types of exercise activate different muscle fibers. Strength training helps recruit fast-twitch fibers, leading to muscle growth. These can be further broken down into type IIa and type IIb muscle fibers. 

Type IIa fibers rely on both anaerobic and oxidative metabolism to generate force, according to the University of New Mexico. They also experience an increase in cross-sectional area in response to strength training. 

Type IIb fibers, on the other hand, rely on anaerobic metabolism and are capable of generating the greatest amount of force. Resistance training may increase their oxidative capacity and help convert them into type IIa fibers. 

Slow-twitch fibers have little or no impact on hypertrophy but play a key role in endurance training. Swimmers, marathon runners, cyclists, and other endurance athletes have a larger number of slow-twitch fibers compared to bodybuilders, for example. This allows them to work out for a longer time without getting fatigued. 

Twitch Fiber In-Depth Comparison

Feeling confused? Here’s a quick breakdown of the primary types of muscle fibers and their role:

Slow-Twitch Muscle Fibers 

• Enable continuous muscle contractions over a long time due to their ability to use oxygen for fuel 
• Are more resilient to fatigue than fast-twitch muscle fibers
• Come into play during long-distance running, cycling, and other endurance activities
• Produce less force and power than fast-twitch fibers 
• Rely solely on oxygen for energy

Fast-Twitch Muscle Fibers 

• FT IIa fibers use oxygen to convert glycogen to ATP (adenosine triphosphate) and generate force
• FT IIb fibers only use the ATP stored in muscle cells and therefore, rely on anaerobic metabolism
• Generate greater force and power than slow-twitch fibers but fatigue more easily
• They can increase muscle size and definition in response to strength training and/or high-intensity training
• Are used for short-duration activities that require a lot of power and strength, such as heavy lifting 
• They become active only after slow-twitch fibers are recruited

If your goal is to build mass, you must lift heavy and train at high intensity. This way, you’ll get past the type I recruitment and activate your fast-twitch fibers, which are responsible for muscle growth. The heavier you lift, the more type II fibers will come into play.

Anabolic Hormones and Muscle Hypertrophy 

Testosterone, insulin-like growth factor-1 (IGF-1), and other anabolic hormones fuel muscle growth too. As an athlete, you can optimize your hormone levels through diet, training, and proper rest. 

According to the American Council on Exercise, resistance training — especially moderate to heavy loads performed for high-rep ranges — stimulates the release of testosterone, growth hormone, and IGF-1. Your body produces these hormones following strength training to build and repair muscle tissue. 

As the scientists point out, heavy lifting with short rest periods may increase anabolic hormone production and maximize hypertrophy. Adequate rest is crucial too because testosterone and growth hormones are produced during the REM (rapid eye movement) sleep. 

Failure to get enough shuteye may suppress hormone release and protein synthesis while increasing the stress hormone cortisol levels. This can lead to poor recovery and catabolism, or muscle loss. 

Make sure you also proper rest between workouts. Wait about 48 to 72 hours before training the same muscle group. 

Anabolic Hormone Production

As far as anabolic hormone production goes, this process depends on a multitude of factors, including but not limited to:

• Age
• Gender
• Body composition
• Activity level
• Overall health
• Type of exercise
• Workout intensity 
• Nutrition
• Sleep duration

Testosterone levels, for example, tend to decline with age. It’s estimated that approximately 40% of men over 45 have low testosterone. Most studies suggest that testosterone production decreases by about 1% per year after age 30. 

A sedentary lifestyle, alcohol consumption, weight gain, and certain medications and health conditions all can affect your T levels. If your body doesn’t produce enough of this hormone, you may find it hard to build and preserve lean mass.

Depression, mood swings, abdominal obesity, and sexual problems may occur too. 

But there are ways to increase testosterone production and feel like yourself again. 

Simple things, such as eating more protein and lifting heavy, can make all the difference. You may use also use a natural testosterone booster to balance your hormones and stimulate hypertrophy. 

Eat Big to Get Big: Load Up on Protein 

As discussed earlier, nutrition and hypertrophy are strongly connected. You not only need to stay in a caloric surplus but also strike your ideal macro balance. Overfeeding alone isn’t enough to stimulate muscle growth, according to the review published in the journal Frontiers in Nutrition. 

A diet rich in sugar and junk food will result in fat gain. Hypertrophy is an increase in muscle mass, not fat mass. Your body needs quality protein, carbs, and healthy fats along with micronutrients to build muscle and perform optimally. 

The above review recommends a daily protein intake of 1.6 to 2.2 grams per kilogram of body weight. Larger amounts don’t offer any additional benefits. 

The International Society of Sports Nutrition, on the other hand, states that athletes should aim for about 1.4 to 2 grams of protein per kilogram per day to build and maintain lean mass. 

If you’re a bodybuilder or powerlifter, get around 0.24 grams of protein per kilogram of body weight per meal or up to 70 grams per meal to reduce muscle breakdown. 

Protein quality matters too. Get this nutrient from whole and minimally processed foods, including beef, poultry, fish, eggs, low-fat dairy, and legumes. 

A premium protein blend, like Vintage Brawn™, will fuel your muscles and facilitate hypertrophy without adding empty calories to your diet. 

Our formula is free of added sugars, preservatives, additives, and other artificial substances. Plus, it contains both fast- and slow-digesting proteins, so you can use it anytime throughout the day. 

Another advantage of protein is that it helps preserve lean mass during periods of strenuous training and strict dieting. This means that if you’re working out harder than usual, a high-protein may reduce catabolism. On top of that, it will keep your metabolism up and improve recovery time. 

Be Smart about Carbs and Fats 

Protein is the only nutrient that can significantly change body composition when used as part of a balanced diet and training plan. 

Dietary fats and carbs have a negligible impact on the fat-to-muscle ratio, according to Frontiers in Nutrition. However, these nutrients do affect athletic performance. 

Strength training can deplete muscle glycogen stores by 30 to 40%, as the researchers note. Carbs help replenish your glycogen stores and fuel your workouts. A daily intake of 4 to 7 grams of carbs per kilogram of bodyweight seems reasonable for most bodybuilders. 

The same review points out that dietary fat should account for at least 15 to 20% of an athlete’s daily calorie intake. In a clinical trial, resting testosterone concentrations decreased by 12% in men who switched to a low-fat diet. 

Omega 3s

Certain fats, such as omega-3s, increase anabolism and hence promote hypertrophy when combined with resistance training. These polyunsaturated fatty acids occur naturally in salmon, mackerel, tuna, sardines, nuts, seeds, and other whole foods. 

If you’re not a fan of fish or nuts, consider taking omega-3 supplements. Old School Labs’ Vintage Balance™ offers just the right amounts of omega-3s, omega-6s, and omega-9s. This combo promotes cardiovascular health, keeps your brain sharp, and boosts your natural defenses. 

Omega-3 fatty acids, for instance, may protect against depression and improve brain function, reports the journal Oxidative Medicine and Cellular Longevity. 

These potential health benefits are largely due to their anti-inflammatory properties. A diet rich in omega-3s may also lower your risk of heart disease and colorectal cancer, among other ailments.

Maximize Your Gains with Progressive Overload 

As mentioned earlier in our post, progressive overload plays a key role in hypertrophy. 

This concept involves a gradual increase of stress placed on the body during exercise. Besides promoting muscle growth, it stimulates the development of stronger bones, joints, and tendons, it improves athletic performance, and boosts overall strength. 

From lifting heavier weights to increasing workout volume, there are several ways to progressively overload your muscles. Use these strategies to maximize your gains: 

• Gradually increase the amount of weight
• Work out more often
• Change the number of reps or sets 
• Increase the time under tension of a muscle during each rep
• Introduce a new element, such as new exercises or a different type of gym equipment (like kettlebells instead of dumbbells)
• Switch to more challenging variations of your go-to exercises
• Incorporate unilateral training into your routine (do pistol squats instead of barbell back squats, for example)
• Increase workout intensity
• Try advanced lifting techniques, like supersets, drop sets or pyramid sets

The whole point is to constantly change your workout routine and keep your body guessing. If you do the same things over and over, your muscle and strength gains will stall. 

Not sure where to start? Check out these crazy workouts of the 70s! Some of the biggest names in bodybuilding used these exercises and lifting techniques to shape their incredible physiques.

Train, Eat, Sleep, Repeat 

You’ve probably seen those tank tops that have the words Eat, Train, Sleep, Repeat printed on the front. Adopt this mantra if you’re serious about building mass. Your diet, workouts, and sleep schedule are equally important when it comes to hypertrophy. 

Muscle growth can be achieved through weight training. However, doing hundreds of squats or barbell curls won’t get you too far. You need to plan your workouts and continuously challenge your muscles in order to see noticeable results. 

Still wondering what is hypertrophy? See our guide on how to build muscle and take it from there. We’ll break down the most effective workouts and how to get the most out of your gym time. 

Next, check out the five rules of workout nutrition and plan your meals accordingly. Supplement your diet with Vintage Build™, our complete formula for mass and strength gains. 

What’s your strategy for muscle growth? Do you bulk and then cut, change your training plan, or both? Share your experience in the comments section below!