Skip to content

The science of beginner growth

Die Wissenschaft der Anfängerzuwächse

Here is a brief summary:

  1. The term beginner gains refers to the rapid increase in muscle mass that occurs when people with little or no experience training with weights begin to perform resistance training.
  2. Most men who are just starting to train with weights can expect to gain between 10 and 12 kilos of muscle during their first year of training, while women can expect to gain about half this amount. After these initial gains, however, progress slows dramatically.
  3. Even if you've been following a poorly designed training program or diet, you can still make beginner-like gains even if you've been training for several years (read on to find out how).

If you've just started exercising, then I envy you. You have an advantage that I and every other experienced exerciser will never have.

You might be wondering what this advantage is. In a nutshell, it is the ability to build muscle quickly. The sad truth is that experienced gym bunnies have less chance than a snowflake on the sun of building more than five pounds of muscle in a year (and that five pounds is already very optimistic).

For you, however, this is great news.


Well, if you've never trained with weights before, have just started training, or have made little progress since you started training, then you can build muscle a lot faster than I can.

If you're skeptical now, I can understand that.

  • Maybe you think you're a "hardgainer" whose destiny is to stay lean and weak
  • Maybe you think you've already built every milligram of muscle your body has to offer and that your only hope of becoming more muscular and stronger lies in the use of banned performance-enhancing substances
  • Maybe you think you won't build muscle or strength if you start working out with weights because your cousin's boyfriend's babysitter said it didn't work for him.

Well, I would bet all my stinky workout socks and all my stained workout shirts that none of this is true. I've worked with countless people who thought something similar and all of those people became more muscular, leaner and stronger after following my advice.

And those who really got their diet and exercise regimes on track achieved most of their gains within the first six months. Often they did this while gaining very little body fat or sometimes even losing fat.

This is the phenomenon referred to by exercisers as 'beginner gains' and there are many conflicting opinions on the subject online. Some say that even though some people can make beginner gains, others are not so lucky.

Others say that more or less anyone can build truckloads of muscle and little or no fat while eating whatever and however much they want, as long as they pulverize their muscles with weights. Still others say that you can only make beginner gains if you're an absolute beginner, but will be out of luck with this if you've been training for a while.

Who is right?

Well, both groups are right and wrong. The truth is that if proper training and nutrition are new to you, you can build more muscle during your first year of training than you ever will again in your life. However, it's also true that it's easy to bypass this productive phase if you make some common mistakes.

In this series of articles, you'll learn the following:

  • What beginner gains are and what causes them.
  • How much you can expect to build during this beginner growth phase.
  • Why beginner gains will always come to an end.
  • Whether you can miss beginner gains
  • How you should train and diet once your beginner gains are over.

Let's start by defining what exactly beginner gains are.

What are beginner gains?

The term beginner gains refers to the rapid increase in muscle mass that occurs when people with little previous weight training experience start training with weights. Typically, these people are also able to build muscle quickly while gaining very little fat or in some cases even losing fat.

This happens because your body is overreactive to the effects of resistance training when such training is new to it. As a result, when you're just starting to train with weights, you can build muscle much faster than you would after years of training.

For reasons we'll get into in a moment, beginner gains tend to last for about a year, with much of that progress coming during the first 6 months after you move your first barbell. If you play your cards right, this first year of training can be one of the most productive you'll ever experience. However, if you play your cards wrong, you won't make that kind of progress.

Let's start on the positive side and look at how much muscle mass you can expect to build during your beginner phase if you do everything right.

How much muscle can you build during your beginner gains phase?

Sadly, there is very little research on how quickly you can build muscle as a beginner when training with weights. There is also little research that has looked at how much muscle mass you can hope to build over your lifetime. In addition, the little research that does exist on these topics suggests that the ability to build muscle can be highly variable.

A study conducted by scientists at Indiana University sheds some light on the question of how much muscle you can build as a beginner (1). In this study, the scientists had 585 untrained men and women perform bicep curls with their non-dominant arm for 12 weeks. During their training sessions, the subjects performed 3 sets of curls, starting with a weight they could perform 12 repetitions with before reaching muscle failure and increasing the weight until they could only perform 6 repetitions.

The study does not mention how often the subjects performed this workout, but they probably performed it once a week. The scientists documented strength and biceps muscle mass using an MRI before the study began and after it ended.

On average, the subjects' biceps grew by 19% and their 1RM weight (the maximum weight with which a technically correct repetition can be performed) increased by an average of 54%.

However, when looking at the individual data of each subject, it is noticeable that not everyone achieved the same results with these training sessions. Some subjects' biceps became slightly smaller and one subject's biceps grew by as much as 60%, which is three times the average growth. Some of the subjects experienced no strength gains, while one person increased their strength by 250% when doing bicep curls.

As you can see, some people experience far greater beginner gains than others, but almost everyone experiences a rapid and substantial increase in mass and strength when they start training. So instead of picking apart the few studies that exist on this topic and trying to construct an answer from them, we can also turn to expert opinion and real-world experience for more useful answers.

And when it comes to experts, few have more experience when it comes to estimating the ability of novice exercisers to build muscle than Lyle McDonald and Alan Aragon.

Let's look at their conclusions first and then take a look at another method I've developed.

Lyle McDonald's answer

Lyle McDonald is a well-known author and researcher on training and nutrition, and runs - one of the best resources for in-depth background knowledge on these topics that the web has to offer.

Here's Lyle's estimate of how much muscle mass you can build in a year:

Years of Proper Training

Potential rate of gains per year


20 to 25 pounds (2 pounds per month)


10 to 12 pounds (1 pound per month)


5 to 6 pounds (0.5 pounds per month)


2 to 3 pounds (0.25 pounds per month)

His formula is based on his extensive research of the professional literature and experience with countless clients he has helped improve their body composition. Based on what he has read and seen, he estimates that men can gain between 20 and 25 pounds of muscle (about 2 pounds per month) during their first year of proper training. Keep in mind that he's talking about 20 to 25 pounds of pure muscle mass, not just 20 to 25 pounds of weight gain.

A common misconception among novice exercisers is that any weight gain after starting a resistance training program is muscle. This is the reason you'll often hear beginners say they've gained 40 or 50 pounds of muscle during their first year of training.

Of course, this is not true. In reality, they've gained 40 or 50 pounds of body weight, half of which, if they're lucky, is muscle, while the other half is a combination of body fat, water and glycogen (and if they make some of the mistakes we're about to talk about, most of the weight gained could be fat).

Lyle estimates that women can build about half as much muscle as men during their first year of training, which equates to 10 to 12 pounds of muscle (or about 1 pound per month).

Alan Aragon's answer

Alan Aragon is a published scientist and fitness consultant who has been developing nutrition and exercise programs for over 20 years. Based on what he has observed in his work with people ranging from average gym goers to Olympic athletes, most men can build muscle at the following rate:

As you can see, Alan's muscle-building program is based on gaining a percentage of your body weight per month. Of course, this is only accurate for people who are relatively lean or have a body fat percentage of 10 to 20% (for men) or a body fat percentage of 20 to 30% (for women). This is because a 1% increase in body weight for a person with a healthy body weight will be much lower than a 1% increase in weight for a 180 kilo obese person.

Here is an example of how this formula works:

When I started training with weights, I weighed about 64 kilos with a body fat percentage of 10%. According to Alan's model, I could expect to gain 0.64 to 0.96 kilos of muscle per month, which is similar to Lyle McDonald's conclusions. (However, I only gained just under 5 kilos of muscle during my first year for reasons I'll get to in a moment).

Last but not least, I would now like to go through my model.

Armi's answer

Lyle and Alan's answers will be accurate for most people and they are usually what I refer to when people ask me what they can expect when they start training with weights. However, some people are looking for more precise answers (whether they need them or not), so I'd like to share a slightly improved and more accurate formula for estimating your ability to make beginner gains.

This formula is based on Casey Butt's physique model of muscle gains, which states that the amount of muscle mass you can build over your lifetime depends on the size of your skeleton. This model is probably the most accurate model for estimating your ability to build muscle.

Once you have this figure to hand - how much muscle mass you can hope to build over your lifetime - you can put the cart before the horse and estimate how much muscle mass you can expect to build at different times in your muscle building career.

Based on my experience, people who do everything right in terms of their training and nutrition can realize about 50% of their potential lifelong gains during their first year of training. In the second year, you can achieve about half the gains you can achieve during the first year. In year three, you can achieve about half the gains of year two, and so on.

You may now be wondering whether you won't reach your genetic limit for muscle growth after enough years of training. The answer to this question is both yes and no. There is an absolute maximum amount of muscle mass you can build over the course of your life, but this is a variable value and science is not entirely sure whether the gains actually stop or are simply too slow to be reliably measurable.

You can think of muscle gains as similar to Zeno's measurement paradox - also known as the dichotomy paradox. This little thought experiment explores what would happen if you took a series of continuous steps forward towards a wall, with each step being half the distance to the wall.

So if the wall is 3 meters away, your first step would be 1.5 meters. The second step would be 0.75 meters and the third 0.375 meters. If you were to plot the distance to the wall as a curve after each step, the curve would be an asymptote, which means that the curve would get closer and closer to the zero line (which corresponds to contact with the wall), but the curve would never touch this line.

The whole thing would look something like this:

If you want a good model for beginner gains, replace the word curve with your ability to build muscle and the word asymptote with your ultimate genetic potential for muscle gains.

While I don't have formal data to prove this, based on my observations muscle gains follow a similar pattern to Zeno's measurement paradox. This would also help explain why experienced exercisers are able to make gains even when they have been training perfectly for many years and their body weight has been stable for years. In reality, even experienced exercisers can probably continue to make small gains in muscle mass, but they are simply too small to be easily measured or seen at first glance.

Now that we've cleared that up, let me show you how to use this model to estimate how much muscle mass you can gain during your first year of training and in the years after.

  1. First, roughly estimate your body fat percentage. When I started training, my body fat percentage was around 10% and I weighed 64 kilos, so I will use these figures for this example.
  2. Next, estimate how much lean body mass you are carrying around by subtracting your body fat percentage from 100 and dividing the result by 100 to get a decimal factor. In our example, 100 - 10 = 90 and 90 divided by 100 gives a factor of 0.9. Multiply this factor by your total body weight. In my example, this is 64 kilos * 0.9 = 57.6 kilos of fat-free body mass.
  3. Next, estimate how much muscle you can expect to build over your lifetime using one of the Casey Butt Natural Muscular Potential online calculators (here or here: You will need your wrist circumference (Wrist Circumfence) and ankle circumference (Ankle Circumfence). Enter 0% as your body fat percentage. Using my values, this calculator resulted in a maximum value of 82 kilos of fat-free body mass
  4. The next step is to subtract your current lean body mass from this value to estimate how much muscle mass you can build over the course of your life. For me, this resulted in 82 - 57.6 = 24.4 kilos of muscle mass.
  5. Next, multiply this value by 0.5 (50%) to estimate your potential beginner gains during your first year of training. For me, this resulted in 24.4 * 0.5 = 12.2 kilos of muscle mass. If you want to estimate your muscle building potential for your second year of training, then multiply these 12.2 kilos by 50%, which gives you 6.1 kilos of muscle mass.

Graphically, my potential gains for the first 7 years would have looked like this (weight is in pounds):

I would take this even a step further and say that the majority of your gains during the first year of training will tend to occur during your first six months of training. A trainee with average genetics could expect to gain between 5 and 7 kilos of muscle within the first six months (which equates to 0.8 to 1.2 kilos per month). During the following 6 months, his gains will probably be more in the range of 2.5 to 5 kilos (0.4 to 0.8 kilos per month).

Even though you won't be building muscle at breakneck speed during the second 6 months as you did during the first 6 months, 0.4 to 0.8 kilos of muscle gain per month is still exceptional progress, so it's fair to say that your beginner gains will last for about a year.

In the next part of this article series, I'll go into more detail about why many exercisers report larger gains during their beginner phase and why beginner gains end after about a year.


By Amistead Legge

Previous article The definitive guide to preventing muscle loss