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The Ultimate Muscle Growth Training Guide


calendar-iconMarch 12, 2021

Foundational Training Series


Heads up! This article is connected to our Muscle Growth Journey page. For the complete picture on how to build muscle using our evidence-based system, check it out here!

One of the most common fitness goals is to build more muscle. 

Despite so many people wanting to learn about muscle growth, there is still a significant amount of confusion and conflicting ideas on the very best ways to build muscle. 

With so many theories floating around online as well as in person, even a veteran fitness junkie can be left hopelessly confused. 

So what are the tried and true, evidence based ways to build muscle? 

In this guide, we’ll answer that question and more. We’ll cover everything from the basics of muscle growth, all of the variables involved in training for muscle growth, and even some frequently asked questions when it comes to training for muscle growth. 

Welcome to the Ultimate Muscle Growth Training Guide!

The Biology of Muscle Growth

There are three main causes for muscle growth. You can cause all of them with resistance training (lifting weights)!

What Causes Muscle Growth?

First, we’ll go over the basic biology of muscle growth, and what needs to happen in your body for muscle growth to occur.

Muscle growth, also known as muscular hypertrophy, is the process of making your muscles grow larger

Various studies show there are three primary factors that are theorized to cause muscle growth. They are:

  1. Mechanical tension
  2. Metabolic stress
  3. Muscle damage

We’ll define them all for you right here!

Mechanical tension

One of the ingredients for muscle growth is mechanical tension.

Mechanical tension in resistance training is the force that is used to move weight in an exercise. 

For example, you create mechanical tension during a bench press in order to push the weight off of your chest. 

Chris Beardsley describes mechanical tension as the type of force that is used to try to stretch a material.

Metabolic Stress

The second variable that contributes to muscle growth is metabolic stress.

Metabolic stress training is training that maximizes blood flow in the muscle. This increased blood flow drives metabolites into the muscle, such as lactate and hydrogen, that facilitate muscle growth. 

In gym culture this increase in blood flow is called "the pump", a term popularized by Arnold Schwarzenegger.

Muscle Damage

The third and final variable that contributes to muscle growth is muscle damage. While it may sound harmful, muscle damage can be crucial to muscle growth! 

Through exercise, you can create small tears in your muscles. With proper rest and nutrition post-workout, your body then repairs these micro-tears and builds the muscle back, oftentimes bigger and stronger. 

By now you may be wondering, though, how can you introduce these variables in your workout routine and get your muscles growing? We’ll answer that next.

So how do you facilitate muscle growth in your body?

One way to induce all ingredients for muscle growth (mechanical tension, metabolic stress, and muscle damage) is through resistance training, or lifting weights. In that sense, resistance training is the key if you want to create the stimulus to grow your muscles!

Of course, this leads to various other questions such as "What kind of resistance training is best for optimal muscle growth?" and “How can I design my resistance training program to maximize my muscle growth?” 

Fear not! Next, we’ll show you exactly what makes for a resistance training routine that maximizes muscle growth in this next section!

Training For Muscle Growth

To maximize the effectiveness of your muscle growth workout, you just need to focus on three variables: intensity, volume, and frequency!

With a better understanding of what happens in the body during the muscle growth process, and how resistance training is the catalyst for that process, we can now walk through everything you’ll need to consider while designing a training routine for maximum muscle growth. 

We’ll start with how heavy you should lift to build muscle!

The Best Intensity For Muscle Growth

Intensity is how heavy you lift in a resistance training workout. Ideal intensity for muscle growth is 60-80% of your 1 rep maximum!

One variable to consider when constructing a workout for optimal muscle growth is intensity, or how heavy you lift for any given exercise. 

In resistance training programs, intensity is the amount of weight lifted or resistance used in an exercise. One way to adjust intensity is to increase the amount of weight you are lifting or using as resistance.

Research shows that if you lift with more weight, you will get stronger faster (but be careful not to lift more weight than you can do so with proper form).

Intensity is usually measured as a percentage of the 1 rep maximum (1RM), or the maximum amount of weight an individual can lift for 1 repetition. For example, if your 1RM for squat is 200 lbs, squatting 100 lbs would be lifting at 50% intensity.

While you can figure out your 1RM the old fashioned way in the gym, there are also calculators that you can use to get an estimate. We recommend this calculator from symmetric strength!

All in all, it is generally recommended to lift within the range of 60-80% of your 1RM for optimal muscle growth. Going above or below this can be useful for periodization (we will discuss this more later in the post).

The Best Volume For Muscle Growth

Volume is how many reps per week you perform with any given muscle group. Ideal volume for muscle growth is 60-120 reps per week!

Another important variable in a resistance training program is the total number of repetitions performed during a training session at a given intensity, also known as volume. 

You can adjust the volume by adjusting the total repetitions you are performing during an exercise.

Research shows that volume is one of the most important factors to muscle growth. If you do not work your muscles out enough, they will not grow.

Volume is typically measured on a weekly basis by exercise or muscle group. For example, if you do 3 sets of 10 squats with 100 lbs on Monday and on Friday, your weekly volume for squats is 60 reps at 100 lbs (3 sets x 10 reps x 2 days of the week).

Studies also show that any muscle groups for any given exercise show the greatest growth when there are 40-80 repetitions per week per exercise for any given muscle group. The lower end of this range would be appropriate if you are lifting more weight, and the higher end of this range if you are lifting lighter weight.

The Best Frequency For Muscle Growth

Frequency is how many times you exercise a muscle group per week. Ideal frequency for muscle growth is 2 times per week!

Another variable to consider when constructing your training plan for maximum muscle growth is the number of times a muscle group is exercised within a training week, also known as frequency.

Similar to measuring volume, frequency is typically measured in terms of specific muscle group or exercise. 

For example, if you do squats on Monday and Friday, your frequency for squats is twice per week.

Research suggests that a frequency of 2-3 times per week has been correlated with optimal muscle growth. Simple as that!

The Best Exercise Types For Muscle Growth

You may also be wondering how to choose exercises for your training routine if you want to prioritize muscle growth. 

When choosing exercises for your training routine, there are three questions to ask about the exercise you are thinking about adding:

  1. Is the exercise a compound or an isolation exercise?
  2. Is the exercise a unilateral or a bilateral exercise?
  3. Is the exercise a free weight or a machine exercise? 

The answers to these questions will determine the strengths and weaknesses that exercise will have in your training routine as it concerns muscle growth. 

For example, a barbell bicep curl is an isolation, bilateral, free weight exercise, and will carry all the benefits of those exercise types. 

In a workout for optimal muscle growth, you want to use a variety of these exercise types!

So what do these exercise types mean and what are their benefits? We break it all down in this section.

Compound vs Isolation Exercises

You'll want to include both compound and isolation exercises in your workout, as they each have their advantages!

One choice in building your workout is between compound exercises and isolation exercises.

Compound exercises are exercises that work multiple muscle groups at the same time, like the bench press or military press.

Research shows that compound exercises are more efficient means of muscle growth because they recruit multiple muscle groups at a time. This creates greater training volume and intensity, both of which lead to greater muscle growth.

Isolation exercises are exercises that work a single muscle group at a time, like a bicep curl or tricep extension. Research suggests that isolation exercises can be useful targeting specific muscles for muscle growth, and in stressing muscles that aren't worked directly in a compound exercise.

Isolation exercises can also be particularly useful if one muscle group is lagging behind another and creating imbalances within a compound exercise that relies on the strength of multiple muscle groups.

Knowing this, when choosing between compound and isolation exercises:

  • It's best to utilize compound exercises to hit more muscles at once
  • Use isolation exercises to address growing a specific muscle

So, whether you choose a compound or isolation exercise will depend on what you want to accomplish, but you’ll want both to be involved in your workouts to get the best of both worlds. Variety is key!

Free Weight vs Machine Exercises

You'll also want to include both freeweight and machine exercises in your workout, as they each have their advantages!

In building your training regimen, you'll also be faced with the decision of using free weights or machine exercises. 

Free weight exercises are exercises where the resistance is provided by a barbell, dumbbells, or any other free moving object, such as a barbell squat or a dumbbell bent-over row. The object being moved is on a free path – no cables, no attachments – nothing. Research shows that free weight exercises are useful because they recruit more muscle fibers, which is beneficial for muscle growth. This is because they require more muscles to control the path of resistance.

Machine exercises are exercises that provide resistance through a fixed path or range of motion, such as a smith machine bench press or leg press machine. While they don’t offer the same benefits as free weight exercises, machines exercises offer their own advantages, such as:

  1. Safer to perform
  2. Prevents improper form
  3. Easier to do

Research of resistance training does note that machines also allow for the performance of some exercises that are not practically accomplished with free weights

Imagine doing leg extensions with free weights! So, even though free weights may offer more in terms of muscle growth, machines are better to utilize in some cases.

Knowing this, when choosing between free weight or machine exercises, it depends on the situation.

It's best to utilize free weight exercises to stress your muscles more dynamically, and use machine exercises while learning a new motion or to add more weight to specific motions that are difficult to perform with free weights. 

Similar to the choice between compound and isolation exercises, using a mix of both free weight and machine exercises will allow you to get the benefits of both! Once again, variety is good for your workout routine and muscle growth.

Unilateral vs Bilateral Exercises

Lastly, you'll also want to include both compound and isolation exercises in your workout, as they each have their advantages!

A final choice you'll have to make when choosing the exercises for your workout is between unilateral and bilateral exercises. 

Bilateral exercises are exercises where you perform a motion with both sides of your body simultaneously, like an overhead press. Bilateral exercises are useful because they allow you to use greater resistance while both halves of your body work together. 

Bilateral exercises are also time efficient – you don't have to take the extra time to perform repetitions for each side of your body.

Unilateral exercises are exercises you only use one side of your body independent of the other, like a dumbbell lunge or a single arm overhead press. Unilateral exercises can be useful when you have an injury that prohibits the use of an arm or a leg. Studies show that unilateral exercises also have different levels of muscle activation, which can be useful for progressive overload.

Research shows unilateral exercises are just as effective as bilateral exercises when it comes to muscle growth, so don’t worry about losing any potential strength gains or muscle growth by doing one over the other.

So, when choosing between unilateral and bilateral exercises, each has its own benefit for specific situations, but using a mix of both over time will help to maximize muscle growth. 

Variety is once again the best solution for more muscle!

The Best Exercise Order for Muscle Growth

Exercises performed earlier in your workout will enjoy a number of benefits!

Once you’ve chosen what exercises you want in your workout, another important choice is picking the order of those exercises.

While this may seem like a minor detail, research has shown that the order you do your exercises in can have significant implications on your muscle growth and overall performance.

First and foremost, order affects the rate of muscle growth you'll experience from any given exercise. Research has shown that greater muscle growth occurs in muscles utilized by exercises performed earlier in workouts.

In other words, if you perform your bench press before your overhead press on an upper body workout, you can expect greater muscle growth in your chest than in your shoulders.

Research also shows that the volume of any given exercise decreases the later that exercise is performed in a workout. This means if you perform your bench press before your overhead press on an upper body workout, you can also expect to perform more reps on your bench press than if you were to perform it after.

Studies show that the neural activation of muscles goes down the later the exercise is in a routine. This means that exercises performed later in a workout have lower overall muscle activation and lower output of strength relative to exercises done earlier in a workout

These studies also noted that the performance of an exercise is negatively affected even if none of the exercises before it involved the same muscle groups. This means that even if you were to perform squats before your bench press, where there is no crossover in muscles involved, your bench press sets will still suffer compared to when you perform them first!

Lastly, research shows the order of exercises can affect the rate of perceived exertion (RPE) of an exercise. In other words, where an exercise falls in a routine can affect how difficult the exercise feels. That means that how difficult your squats would even feel more difficult if you were to perform them last in a workout rather than first.

The bottom line is that when choosing your exercise order, you should prioritize the exercises that involve the muscles you want to grow the most. In general, it is a good rule of thumb to do compound movements before isolation movements during a workout. This is because compound exercises use more muscles than isolated exercises, which means you need more energy to do the compound exercises. 

Moreover, since compound exercises use more muscles, doing them earlier in a workout when you have more energy will lead to overall greater muscle growth in your entire body.

The Best Exercise Technique for Muscle Growth

With an understanding of exercise choice and exercise order, it's time to discuss how to actually perform exercises in the right way. 

Exercise technique is important to not only preventing injury, but also maximizing your muscle growth.

While there are different techniques for every exercise, there are some general rules you should always follow in order to get the most out of any exercise and build the most amount of muscle.

Range of Motion

Fig. A: Full range of motion means taking a muscle through the entire range in which it is able to move. This figure shows you the full range of motion for a bicep curl. Full range of motion will help your muscles to grow more quickly!

One aspect to always keep in mind while performing an exercise is range of motion. Full range of motion is the full movement potential of a joint, or its range of flexion and extension. For example, in a bicep curl, the full range of motion is covered as you move your arm from a straight position to a position where it is completely bent (Fig. A)

As far as your fitness routine is concerned, you generally want to perform any exercise with its full range of motion. Research shows that full range of motion allows the maximum amount of muscle to be worked, which is the stimulus for muscle growth.

Research shows that full range of motion allows the maximum amount of muscle to be worked, which is the stimulus for muscle growth

It is important to note that there are exceptions to this rule. Sometimes an injury or lack of flexibility can limit your range of motion, in which case you should only use the range of motion that is comfortable to you. Further, some exercises purposely limit the range of motion in order to add variation to an exercise or target a weak point.

Eccentric and Concentric Motion

When performing an exercise, the range of motion can be divided into two parts: the eccentric and concentric motion. 

The concentric motion of an exercise is the muscle shortening portion, while the eccentric motion is the muscle lengthening portion. 

For example, in a bicep curl, lifting the weight up and shortening the bicep is the concentric portion of the exercise, and lowering the weight back down under control is the eccentric portion of the exercise.

Oftentimes the eccentric portion of an exercise is neglected – this is a big mistake when it comes to muscle growth. Research shows that lengthening the time spent in the eccentric portion of the exercise has been linked to increased muscle growth. This is partially because your muscles are able to sustain more weight during the eccentric portion of an exercise, so you can actually use greater resistance by isolating this part of the exercise.

So, to promote maximal muscle growth during the repetition of an exercise, attention should be paid to both concentric movements as well as eccentric movements. To ensure this, it is generally recommended to perform each repetition with a tempo of 1-2 seconds each direction, at a moderate velocity. 

Isometric Exercises

A plank is a great example of an isometric exercise, or an exercise where there is no joint movement or change in the length of your muscle.

The vast majority of exercises are covered with concentric and eccentric motion, but there is actually a third time of movement (or lack thereof....) when it comes to resistance training: isometric movement.

Isometric movements are a type of strength training in which the joint angle and muscle length do not change during the exercise. These movements involve stationary muscle tension, like holding a heavy weight above your head or performing a plank. 

Studies show that isometric exercises can be extremely useful in a program for muscle growth, as they facilitate greater muscle recruitment than both eccentric and concentric movements.

There are primarily two types of isometric movements:

  • Overcoming Isometrics: Exercises where a joint or muscle is moving against an immobile object (e.g., pushing against a wall)
  • Yielding Isometrics: Exercises where a joint or muscle is held against resistance (e.g., holding up a heavy weight)

So, in a program designed for muscle growth, research shows you can utilize isometric movements to add variance to your routine, overcoming stalls in progress, and increase strength as well as muscle recruitment.

To really keep your muscles guessing, you can even perform overcoming isometrics at various points within your range of motion! 

Breaking Through Muscle Growth Plateaus

You may find though that even with a perfect training plan and optimal performance, your muscle growth can stall from time to time. So what do you do?

In this scenario, you need to find some way to change your routine so that your muscles keep growing. The keys to this are progressive overload and periodization!

Progressive Overload

Progressive overload means placing higher and higher demands on your muscles (between periods of lighter demands) in order to gradually increase muscle mass and strength!

Progressive overload is the gradual increase of stress placed upon muscles during exercise training. It is central to growing bigger, stronger and more fit.

During a training program, your body adapts to a given workload over time. Studies show that as the body adapts to a particular exercise, it becomes easier to perform and less muscle mass is recruited

In other words, after you do the same exercise for multiple workouts, your muscles get used to the exercise and they don't work as hard.

With lower muscle recruitment, less muscle growth occurs. Progressive overload is the key to keep that muscle growth going!

In other words, progressive overload helps prevent your muscles from getting too used to any particular exercise which helps to continually increase muscle growth.

So how can you implement progressive overload in your workouts? 

In resistance training, there are a number of ways to introduce progressive overload. Below are some of the most popular methods:

  1. Keep changing your exercise intensity – or the weight you use for an exercise.
  2. Adjust the volume of work you are doing, or the number of repetitions you perform for an exercise
  3. Change the frequency of an exercise, or how many times you perform it in a given week.
  4. Change the tempo of how you perform your exercise reps- vary between a faster tempo and a slower tempo every few workouts to keep your muscles guessing
  5. Alter your rest between sets and exercises – changing between less rest and more rest will hit your muscles differently

So if you’ve found yourself stalling, you can implement progressive overload by changing one or more of these variables! Whether it's the weight, number of repetitions, frequency, tempo, or rest time, introducing change will force your muscles to adapt and keep growing!


The second key to keeping your muscles growing is periodization. 

Periodization is a system you can use to repeatedly introduce progressive overload. You just learned about the variables you would alter to introduce progressive overload – periodization is a system you would use to introduce those variables over time. 

Periodization can be applied in weekly, monthly, or even yearly cycles, and has been shown to be extremely effective for long term progression of muscle growth.

There are three commonly used periodization models that have been proven successful. These models focus primarily on changing the intensity and volume of your workouts (variables 1 and 2 from our list in the progressive overload section):

Periodizing your training plan will help create the variety your body needs to build as much muscle as possible, as quickly as possible. Here are the three most common models of periodization!
  • Classic Model of Periodization (Fig A, Graph 1) – In this model of periodization, a resistance training program begins with high initial volume (repetitions) and low intensity (weight) and, over time, shifts to a lower volume and higher intensity workout.
  • Reverse Model of Periodization (Fig A, Graph 2) – In this model of periodization, initial resistance training is performed at high intensity (weight) and low volume (reps), and gradually is shifted to a low intensity and high volume workout.
  • Undulating Model of Periodization (Fig A, Graph 3) – This model of periodization utilizes a variety of volume (reps) and intensity (weight) levels within a given training phase. Instead of focusing on a certain volume or intensity level during a period of time, the undulating model utilizes a range of volume and intensity throughout a workout regimen. Over the course of a year, month, or even a week, you would switch between high volume-low intensity and low volume-high intensity workouts.

Each model of periodization has been shown to be effective when it comes to muscle growth so you can choose whichever model you prefer. By varying the volume and intensity of your training regimen over time, your muscles are forced to constantly adapt to new stimuli, and therefore, continue to grow!

The Importance of Recovery for Muscle Growth

With sufficient rest, you can perform at higher and higher intensities. Without it, you'll just end up breaking down your body and make it more vulnerable to injury!

With a perfectly constructed workout that utilizes progressive overload and periodization, you may feel like you have everything you need to keep working out forever! 

There is one more thing, though, that you might need to do more often if you want to maximize your muscle growth- take a break!

Believe it or not, though, stopping to take a rest every once in a while is not only acceptable, it’s recommended if you want to keep your muscles growing as quickly as possible.

It may sound hard to believe, but well-timed rest and recovery are paramount if you want to stay at 100% and stay in your workout rhythm.

Recovery is an important variable in any training plan. Studies show that muscle growth occurs during recovery from resistance training, so adequate rest is essential.

It has been shown that it typically takes at least 48 hours to properly recover from an exercise. Protein synthesis peaks about 24 hours after exercise, so performing the same exercise within a 48 hour window breaks down muscle that has not yet recovered or grown since the last time it was exercised

With this said, it's recommended that you give your muscles 48 hours of rest before exercising the same muscle group again.

For example, if you hit leg day and did squats on Monday, hold off on another leg day until at least Thursday or later.

Overtraining: What Happens When You Don’t Rest!

Over the long term, you'll also want to incorporate longer periods of rest or lighter work.

In periodized workouts, for example, it's common to have a "deload week” before cycling through the phases again. During this week, you use lighter weights and lower volume in order to make sure your body is fully recovered and ready to go. 

Without proper recovery time, you risk overtraining.

Overtraining is defined as exceeding your body's ability to recover from strenuous training. 

Overtraining is associated with numerous harmful and deleterious symptoms. Studies have shown that someone suffering from overtraining will experience fatigue, decreased physical performance, lower motivation, worsened mood, poor sleep quality, and general disturbances in their hormonal, psychological, and neurological systems.

In serious cases, it can take weeks and sometimes even months to fully recover from overtraining. Milder cases of overtraining (known as "overreaching") usually only take a few days to recover from. 

You can avoid overtraining with proper sleep and nutrition, incorporating deload weeks into your regimen, and making sure to take time off if you begin to feel any symptoms of overtraining. 

Taking a week off may feel unproductive, but in the long run, avoiding overtraining will allow you to maximize your time in the gym and ensure you are making as much progress as possible.


That wraps up our Ultimate Muscle Growth Training Guide! With the information here, you should have everything you need to train for optimal muscle growth. In this guide, we covered:

  • Mechanical tension, metabolic stress, and muscle damage are the three primary factors that induce muscle growth.
  • A simple way to introduce all three of these factors is resistance training (most commonly in the form of lifting weights).
  • When constructing a resistance training plan for muscle growth, you should consider intensity, volume, and frequency.
    • Try to keep your intensity in the range of 60-80% of your one rep maximum.
    • The ideal weekly volume for muscle growth is in the 60-80 repetitions range.
    • Targeting a muscle group 2-3 times per week leads to the most muscle gains
  • When picking exercises for your workouts, ask yourself the following three questions about each exercise:
    • Is it a compound or an isolation exercise?
    • Is it a unilateral or a bilateral exercise?
    • Is it a free weight or a machine exercise? 
  • Using a variety of the above exercise types can ensure you maximize your muscle growth.
  • Exercise order is important to keep in mind, as it can affect muscle growth, exercise performance, and perceived exercise difficulty. 
    • Prioritize exercises that you want the most gains for so they occur earlier in your workout. 
  • When it comes to exercise technique, you should utilize your full range of motion whenever possible. 
    • Be sure to focus on both the concentric and eccentric motions within any exercise. 
  • Isometric exercises can also be very useful for breaking through similar obstacles.
  • If your goal is to gain or retain muscle mass, progressive overload is a necessary ingredient to an optimal training regimen. 
    • Introducing increased intensity, volume, or varying tempo and rest times through a resistance training program is currently the most effective way to introduce progressive overload to your fitness regimen.
  • Periodization is the systematic process of altering one or more program variable(s) over time, to allow for the training stimulus to remain challenging and effective. 
    • The classic, reverse, and undulating models of periodization are all great ways to introduce periodization into your routine and keep your muscles growing. 
    • Regardless of what type of periodization is used, the important concept here is that you regularly adjust training stimuli in a workout program so that they remain challenging in order to facilitate growth.
  • Don't be afraid to take a week or two off! Allowing your body to fully recover from training is important to both your muscle growth and your general health. 
  • Your rate of muscle growth can be roughly determined by your training age, or how many years of optimal training you've had. 
  • Your training age reflects how close you are to your maximum genetic muscle growth potential. 
  • While there is no empirical way to find your exact training age and progression toward your genetic ceiling, relative strength formulas like the Wilks Score can give you a great estimate.
  • Your gains won't go anywhere during a week or two off from the gym, and you'll be able to come back fresher and stronger than ever.
  • Nutrition is also a very important part of growing muscle, and you can read all about that in our Muscle Growth Nutrition Guide

Thanks for reading, and be sure to check out to find the workout right for you!

Heads up! This article is connected to our Muscle Growth Journey page. For the complete picture on how to build muscle using our evidence-based system, check it out here!

Frequently Asked Questions 

Here, we’ll answer some of the most frequently asked questions about muscle growth training.

How Quickly Can I Grow Muscle?

Muscle growth is fastest during your first 2 years of optimal training, and it slows down as you reach your maximum muscular potential.

You may be wondering: just how fast can I put on muscle? The answer to this question lies in your training age. 

Your training age is how many years of optimal training you've had. This is an important concept because it has a significant correlation to how quickly you can grow more muscle.

Research has shown that those who are just beginning to practice resistance training can expect a faster rate of muscle growth, while those with a higher "training age" should expect their rate of muscle growth to slow down over time (fig A).

This means you could be able to gain 6-8 pounds of muscle in your first 3 months of training, but maybe 4-6 pounds months 3-6. As your training age goes up, you get closer to your 'maximum muscular potential', or your genetically predetermined level of maximum muscle mass. 

Research shows that the closer you get to your maximum potential from your training age, the slower the rate of muscle growth will be.

How to Find Your Training Age

So how do you find your training age? 

Currently there is no official way to measure training age, as it is an individual’s progression towards his or her "genetic ceiling", which cannot be empirically determined. We do have reliable methods of estimating your training age, though.

One way to estimate how close you are to your genetic ceiling, however, is to compare your strength to the average strength of others with the same body mass. 

There are several algorithms that can be used to calculate this, but the Wilks Formula is widely employed in strength competitions. 

The wilks formula will give you your “Wilks Score” which is your estimate of how close you are to your maximum strength! When applying the Wilks Formula, individuals who are relatively weaker than most people with the same body mass are considered to have a younger training age, and therefore can expect a faster rate of muscle growth.

Here is a calculator to determine your Wilks Score and relative strength! That will give you an idea of your training age.

Will I Lose Muscle if I Stop Working Out?

A common anxiety is that you'll lose all of your muscle after a week or two off from the gym. Fortunately, studies show that there isn't much to worry about: muscle breakdown usually only begins after 2-3 weeks of not working out, and even then it comes back more quickly than it did initially as soon as you start training again.

A common concern with taking time away from the gym is the risk of losing your hard earned muscle mass during your time off. Fortunately, you can rest easy knowing that the chance of you losing muscle during a week or two away from the gym has been greatly exaggerated by the online fitness community.

Research on muscle atrophy, or the decrease of muscle due to a lack of resistance training, indicates that atrophy usually only begins after 2-3 weeks of not working out. 

More than that, when atrophy does take place, studies show that the lost muscle mass will grow back more quickly than it did initially once you pick training back up. This has been hypothesized to be due to "muscle memory".

You may also notice a decrease in muscle size and strength during a short break, but fear not! Studies show that decreased muscle size during a break is mostly due to decreased glycogen storage and water retention. This is a temporary effect, and will reverse itself quickly once you resume training.

What Should I Eat to Build Muscle?

Nutrition provides your body with the materials it needs to build muscle! Check out more in our Ultimate Muscle Growth Nutrition Guide!

While training and recovery are both very important aspects of building muscle, you’d be hard pressed to find anyone who has built muscle without a proper nutrition plan. 

Training provides the stimulus for your body to build muscle, but nutrition provides the materials it needs to build the muscle. 

We cover everything you need to know about muscle growth nutrition in our Ultimate Muscle Growth Nutrition Guide, but we’ll summarize the basics here.

For optimal muscle growth, you’ll want to make sure your daily nutrition plan follows the following guidelines:

  • Eat 0.8 to 1 g of protein per pound of body weight
  • Eat 250-500 calories above your total daily energy expenditure
  • Make sure at least 15% of your diet is comprised of fats (to ensure your hormonal health)
  • Fill the rest of your diet with carbohydrates to fuel your workouts

For more details, check out our Ultimate Muscle Growth Nutrition Guide!

References and Useful Research

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Last Updated: June 10, 2021

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