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How Long Does It Take to Build Muscle? Understanding the Process

Maintaining high-performing, strong muscles is crucial for a healthy lifestyle. Whether you’re weight training to bulk up or wanting to make changes in your lifestyle, you’re likely wondering how long it takes to build muscle.

The process of building muscle is unique for all of us, and it’s easy to become discouraged when you don’t notice results right away.

So, how long does it take to build muscle? We’re sharing how muscles grow, how long it may take, and factors that affect the span of muscle growth.

Table of Contents

How do muscles grow?

Muscles grow through a process called “hypertrophy”. Hypertrophy is the process the body uses to rebuild damaged muscle tissue, essentially growing the size of the muscle. On a microscopic level, our muscles are made up of fibers, which in turn are made up of proteins. Stimuli like resistance training (weightlifting) can overload our muscles, causing proteins to break down.

After exercise, a chain of events is set off in the body to repair and rebuild damaged muscle fibers. This is called muscle protein synthesis. As a result of these internal processes, our bodies shift between states of muscle protein breakdown and synthesis.

When do our muscles actually grow? They grow when the amount of protein synthesized in our muscles exceeds the amount of protein that is broken down.

cartoon weight lifting

How long does hypertrophy take?

When considering muscle hypertrophy and growth following a single training session, it’s important to understand that protein synthesis is increased in the muscle for 24 to 48 hours immediately after training.

But one training session is not enough to pack on muscle mass. In order to build muscle, you need to put your body in a position where it is consistently in a state where muscle protein synthesis is elevated.

The combination of a consistent diet and a steady training routine is ultimately what leads to gains in size and strength over time. Additionally, proper supplementation can also be an effective means of stimulating muscle protein synthesis immediately after training.

Building muscle is not an immediate process. There may be some improvements on a microscopic level following a single training session, but directly observable results take time.

There are a number of factors such as genetics, age, gender, and training experience that affect how long it takes any given individual to build lean muscle mass.

Which factors affect muscle building gains?

There are numerous things to consider when understanding how long it will take for you to see muscle results. Let’s take a look at some of the different factors that affect the rate at which you are able to build muscle.

  • Genetics

    Genetics can play a role in how quickly you are able to pack on muscle. While some people are more reactive to exercise-induced stimulation, others need different strategies to see similar results.

    A 2005 study recruited 585 adult subjects (342 women, 243 men) and put them through a 12-week resistance training program. The researchers found a wide variation in the amount of size and strength gains made by both men and women in the study.

    Some subjects made little to no gains (one subject even had a 2% loss of muscle mass), while others made substantial improvements — one individual made a 59% increase in muscle mass and another doubled their strength.

    Most people in the study fell somewhere in between these two extremes, making modest improvements in muscle size and strength. About 40% of the subjects increased their muscle mass by around 15%.

    takeaway For the average person, 12 to 16 weeks seems to be enough time to see some modest increases in muscle strength and size.
  • Age

    Age plays a sizable part in our ability to build and maintain lean muscle mass.

    As we grow older, we become increasingly prone to muscle protein breakdown. This can result in a decrease in muscle mass and can negatively impact our quality of life.

    However, older individuals are still plenty capable of exhibiting positive adaptations to weight training.

    A study published in 2011 compared the effect of a 16-week training program on 2 groups of participants. One group consisted of individuals between 20 and 35 years of age. The second group was people between the ages of 60 and 75.

    Coming into the study the older group on average had lower percentages of lean muscle mass compared to the younger group. After 16 weeks of training, however, the older group was able to achieve similar levels of muscle mass compared to the younger group prior to the study.

    Researchers have also found that younger individuals on average, respond better to resistance training than older people.

    takeaway While younger people are generally able to build more muscle in the same time period, older individuals have been shown to achieve measurable gains in muscle mass within 4 months.
  • Gender

    Exercise scientists have long investigated the role of gender in muscle development. It’s been recorded that on average, women are able to gain more strength over the same time period in comparison to men. However, increases in muscle size tell a different story.

    Exercise scientists have found that men are able to develop more muscle in a shorter time frame in comparison to women. This is at least partially due to higher levels of testosterone in men.

    The musculature in the upper body develops more quickly in men than it does in women. A 2005 study compared the developments in arm size and strength in male and female participants over the course of a 12-week program. On average, the men made increases of about 20%, while the women saw increases closer to 18% in the same time period.

    takeaway 16 weeks of training seems to be enough time for both the average man and woman to experience modest gains in muscle mass.
  • Training experience

    Training experience is another factor that can dramatically impact the time frame in which you are able to build muscle.

    Individuals with little to no training experience will likely find it easier to build muscle in comparison to those with extensive training backgrounds.

    The muscles in untrained individuals are far less accustomed to the stresses placed on them by resistance training. Ultimately this leads to more protein breakdown in the muscle tissue, which in turn leads to more hypertrophic gains.

    For instance, a study published in 2003 examined muscle adaptations in a population of young men with no previous training experience. The study found that on average, subjects made increases in muscle size on a macroscopic level after as little as 3 weeks of training.

    Nonetheless, increasing lean muscle mass becomes more difficult as training experience goes up. As you continue to log more hours in the gym, your muscles become increasingly accustomed to the stresses induced by your exercise routine. This leads to less damage done to the muscle tissue (which leads to less hypertrophy).

    The result? Individuals who have been training for years may only experience a few percentages of improvement in lean muscle mass over the course of a year.

    takeaway Packing on lean muscle mass is a substantially quicker process for individuals who have little to no training experience. An average person may be able to make some noticeable gains in muscle size and strength in as little as a month.

    However, as your experience in the gym grows, it will take longer and longer to increase lean muscle mass.
outside workout

How to maximize muscle building gains

When it comes to building muscle, there are a number of factors that are out of our control. But don’t fear! Exercise and program selection also play a large role in our ability to build muscle.

So, what should you be focusing on in your routine if you’re looking to maximize your muscle building potential?

Intensity, reps, and sets

High-resistance exercise has been proven to be more effective in inducing muscle hypertrophy than low-resistance training.

Working at intensities at and above 60% of your one-rep max is the ideal range for building muscle. Each exercise should include multiple sets at a rep ranges between 6-12 for optimal muscle gains.

Rest intervals

In order to maximize the amount of muscle you’re able to build, make sure that your rest intervals are not too short. For instance, if you only wait 30 seconds between sets, you may not have enough time to regain your muscle strength. This leads to reduced performance on subsequent sets.

On the other hand, ensure your rest intervals are not too long. A couple of minutes between sets may allow you to regain strength, but the amount of metabolic stress on your muscles will be greatly reduced. Less metabolic stress means less hypertrophy.

The answer is to meet in the middle. A rest interval sweet spot of 60 to 90 seconds between sets seems to be the optimal range for maximal muscle growth.

Rep speed/tempo

The speed at which we perform sets plays a role in our ability to build muscle. A movement based exercise consists of two motions: the concentric and eccentric portions of the movement.

For example, imagine a bench press. During a bench press, the concentric part of the movement is when the bar is pushing away from the chest. The eccentric portion is when the bar is lowering towards the chest.

The eccentric portion of the movement plays a more important role in damaging the muscle tissue. In turn, eccentric movements maximize hypertrophy.

Exercise scientists suggest that performing the eccentric portion of the exercise at a slower speed puts the muscle under tension for an increased period of time. This places a greater strain on the muscle resulting in the breakdown of more proteins.

To maximize muscle gains, the eccentric portion of your rep should take around 4 seconds.

Training to failure

Training to failure refers to the act of performing the maximum amount of reps you are capable of doing in one set. It is another variable that can affect muscle growth.

Training to failure on every set of every exercise, however, is not recommended. This drastically increases the potential for overtraining, which negatively impacts your ability to build size and strength.

Alternating in your training session between sets that go to failure, and sets that don’t minimize the risk of overtraining and maximizes hypertrophic stimulation.

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Use high-performance supplements

Using the proper supplements will allow you to see faster muscle results. High-performing supplements like Whey Protein and Muscle Protein Optimizer improve muscle recovery and stimulate muscle protein synthesis.

The right supplements will help you recover more quickly and boost the quality of your workout.

Get sufficient sleep

When you sleep, your body balances it’s hormone levels. Failing to get sufficient sleep does not provide the proper balance you need, causing muscle building to move at a slower pace.

You should aim to get 7-9 hours of sleep each night.

Rest your muscles

Following resistance training, it’s crucial that each muscle group has at least 1 to 2 days of rest. Overworking your muscles can have a negative impact on your muscle growth rate and can lead to injury. It’s never advised to work the same muscle group for multiple days in a row.

Wrap up

The way each of us builds muscle looks different from person to person. It’s important to understand the factors that affect how long it takes you to build muscle, as well as the factors you can choose to see the fastest results.

In order for the average person to see modest gains in size and strength, somewhere between 12 and 16 weeks of training is usually a solid amount of time. But no matter where you are in your fitness journey, properly managing your training program is the best way to maximize your muscle building potential.

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