So you start lifting weights. How much muscle can you expect to gain in your first few months? How much weight should you be adding to the bar each week? And how big and strong can you become during your first year? What are good lifetime goals? Or maybe you’ve been lifting for a while and you’re wondering how strong you should be by this point.
Most women are trying to get toned, lose some fat, you know the deal. They don’t want to get too bulky. That might suit their goals just fine, but it’s going to make it almost impossible for them to gain much muscle and strength. But what if you’re willing to gain weight? What if you want “bulky” hips? What if you want to become strong? That changes things. We can do better. Much better. In fact, I have a feeling you’re going to be pretty amazed about what you can do even in just your first year of lifting.
So, to figure out how much muscle and strength you can expect to gain, let’s break the question down into two parts:
1. How much muscle can a naturally thin woman expect to gain?
2. How much strength can she expect to gain?
Let’s dig into the science.
How much muscle can the average woman gain in her first year of lifting?
Before we can talk about how much muscle a naturally thin woman can build in a year, we need to talk about what sets her apart from the average woman. The main difference is that by the time the average woman reaches adulthood, she’s naturally accumulated a fair amount of muscle mass on her frame, partly due to her genetics and partly due to the fact that she’s overweight.
According to the CDC, the average woman weighs around 170 pounds by the time she reaches adulthood, which represents a BMI of about 30. According to Steven Heymsfield, author of Human Body Composition, around 30% of the average woman’s bodyweight is muscle mass. This means that the average woman starts off with roughly fifty pounds of muscle.
The next thing we need to consider is her genetic potential—how much muscle mass can her frame hold? It seems like the average woman’s frame can hold around seventy pounds of muscle, meaning that over the course of her lifetime, she can “only” gain another twenty pounds of muscle. (Twenty pounds of muscle is quite a lot, but it probably pales in comparison to the amount of muscle that you can build.)
However, this growth isn’t linear, it’s logarithmic. During her first year of lifting, the average woman is able to get about halfway to her genetic potential, gaining around ten pounds of muscle. In her second year, that rate of muscle growth will be cut in half, and then cut in half again the next year. Like so:
This initial explosion of growth happens because when she starts lifting weights, her muscles are still extremely sensitive to this new stimulus and still have incredible growth potential. This period of rapid muscle growth is called newbie gains, and it allows the average woman to gain around a pound of muscle per month. She might even be able to lose some fat while doing it.
This rapid growth is possible because her muscle fibres are still small, making it easy for her nuclei to manage them. In fact, her nuclei are already capable of handling significantly larger areas, so her muscle fibres can simply expand, like so:
After a few months, she’ll quickly reach the point where her myonuclear domains are maximized, at which point building muscle starts to get harder. It starts becoming difficult to gain muscle without gaining weight overall, making simultaneous muscle growth and fat loss almost impossible.
Now she needs to bring new nuclei into her muscle fibres before they can grow any bigger. Sort of like needing to hire more managers as your company grows. It looks like this:
Admittedly, this example is oversimplified, and there are other known factors that contribute to the slowing rate of muscle growth (such as the repeated bout effect), but the main takeaway here is that our muscles grow quickly at first, and then as we get closer to our genetic potential, our rate of muscle growth slows.
So all things considered, most experts agree that the average woman can expect to gain around around ten pounds of muscle during her first year. And to be clear, ten pounds is a lot of muscle. That’s enough to add a few inches around her hips and shoulders, dramatically transforming her physique.
Then in the years that follow, she gets closer to her genetic potential, and it gets harder to gain more muscle and strength, which sounds like a total bummer, but keep in mind that by then she already has a totally killer physique, so there isn’t as much of a rush to keep improving:
Once you’ve spent a year or two fighting to gain muscle and strength, you don’t need rapid progress anymore, you can enjoy the benefits of having a strong, healthy, and athletic physique.
This rate of muscle growth raises a couple questions, though:
How come most women who lift weights hardly gain any muscle ever?
How come our members are often able to gain ten pounds in just a few months?
The first question is easy to answer. This rate of muscle growth assumes that you’re following a good bulking program. In order to build muscle quickly and consistently, you have to:
Follow a serious lifting program. Most exercise programs aren’t designed to help women become bigger and stronger. Even most lifting programs for women are more about cardio and endurance than about gaining muscle mass. (Strong Curves by Bret Contreras, PhD, is a great book and a possible exception to this, but it still assumes an overall goal of weight loss.)
Fight to get stronger. To gain muscle, you have to progressively lift heavier and heavier weights. If you start off doing goblet squats with 30 pounds, next week you should be fighting to lift 35. And then 40. Then you switch to a front squat with 45 pounds, and so on. That’s how you gradually work your way up to a 245-pound back squat (which how much you’ll be able to squat a few years from now).
Gain weight. If you aren’t gaining at least a pound on the scale every month, you won’t be able to gain muscle mass anywhere near this quickly. This explains why most women won’t gain anywhere even close to ten pounds of muscle during their first year of lifting weights—they aren’t gaining enough weight overall.
Because of how deliberate you need to be about building muscle, and because of how uncommon it is for women to intentionally gain weight, most women aren’t going to exercise in a way that will help them build a significant amount of muscle. And that’s fair. The average woman is overweight. Weight gain probably isn’t her goal in the first place.
If you’re someone who’s deliberately trying to gain weight, though, you can absolutely hit this target.
In fact, like we mentioned above, if you’re starting off thinner than the average woman, you should be able to gain your first ten pounds within just a few months. And we’re not talking about getting fat or bulky or anything, we’re talking about building up a strong, badass physique:
Okay, on that note, now that we’ve covered how much muscle the average woman can gain, let’s talk about how much muscle a skinny, thin, or generally underweight woman can expect to gain in her first year of lifting weights.
How much muscle can a thin woman gain in her first year?
So the average woman weighs 170 pounds, has 50 pounds of muscle on her frame, and can add another 20 pounds over the course of her lifetime, 10 of which she can gain in just the first year.
Now let’s imagine a naturally thin woman. Let’s say that she’s the same height but only weighs 100 pounds. She’ll likely have slightly thinner bones, a narrower frame, and a smaller stomach, which accounts for some of the weight difference, but most of the weight difference will be due to the fact that she’s carrying far less muscle and fat. For the sake of this example, let’s say that only 25% of her weight is muscle mass. This gives her just 25 pounds of muscle mass on her frame. Half as much muscle as the average woman. She’s starting behind the starting line, like so:
As you can see, given that we see diminishing returns the closer we get to our genetic muscular potential, if she’s further away from her potential, then she’ll be able to build muscle more quickly.
So to flesh out this theory, the next thing we need to do is determine this naturally thin woman’s genetic muscular potential. After all, it doesn’t matter how far away she is from the average genetic potential, it matters how far away she is from her genetic potential.
The best researcher looking into this question is Casey Butts, PhD, who found that the genetic potential of a hardgainer is about 5–10% lower than average (due to having thinner bones and smaller frames). So if the average woman can hold around 70 pounds of muscle, a naturally skinny woman can expect to hold about 63–67 pounds of muscle. That’s a disadvantage, sure, but not a significant one. In fact, given how few women get anywhere even close to reaching their potential, there’s nothing stopping you from becoming far curvier and stronger than almost every other woman you come across:
Alright, going back to our example, we have a 100-pound woman with 25 pounds of muscle on her frame, with the genetic potential to hold up to 67 pounds of muscle. That puts her a whopping 42 pounds of muscle away from her genetic potential!
Given that she’s starting so far away from her genetic potential, she’s starting at the best possible point on the muscle growth curve: right at the very beginning:
This is going to allow for a period of even more rapid growth when she first starts lifting weights, allowing her to quickly catch up to the average woman, at which point she can expect to start gaining muscle at a more typical pace.
But don’t skinny women have worse muscle-building genetics? When I first started trying to build muscle, I assumed that being skinny meant that I wouldn’t be able to build muscle very quickly. That was confirmed by the fact that I was trying everything I could to gain weight and still couldn’t get the damn scale to budge.
Furthermore, the term “hardgainer” is sometimes used to describe someone who struggles to build muscle. The way we use the term, though, a hardgainer is someone who struggles to gain weight.
I know that sounds like a weird distinction to make, given that you need to gain weight in order to gain an appreciable amount of muscle, but our struggle to gain weight has little to do with our muscle-building genetics and more to with having higher metabolisms and smaller appetites/stomachs. In my case, at least, I wasn’t failing to build muscle because I was having a poor response to lifting weights, I was failing to build muscle because I couldn’t get into a calorie surplus—I was failing to gain weight. It was a diet issue.
Once you learn how to eat enough calories, I suspect that you’re going to respond incredibly well to lifting weights. With a proper lifting program, you should be able to greatly exceed all the expected rates of muscle growth:
What if you have naturally small hips? We’ve been talking about overall muscle mass, but one question we get is how big you can specifically build up your hips. After all, many of our members don’t want to bring their biceps to their full genetic potential, but they do want to see how big they can build up their glutes.
Even if you have poor genetics, I think you should be able to build up your glutes to about 90–95% of the size of the average woman who reaches her full potential. And keep in mind that most women aren’t going to get anywhere even close to their full potential, even if they lift weights their entire lives. If you take this seriously, you should expect to be able to build remarkably powerful hips.
Lifting weights gives you quite a bit of control over the type of physique you can build. We generally recommend aiming for overall strength with some extra emphasis on building up your hips, given how strong your hips can become, and how much potential they have for growth, but the cool thing is that you can build the physique that you want.
How is it possible to build muscle that quickly? The research shows that on average women who are new to lifting weights seriously can gain about a pound of muscle per month. There are studies showing far greater rates of muscle growth than that, but, at least on average, most experts agree that a woman following a good muscle-building program can realistically expect to gain about a pound of muscle per month. However, the research also shows that rates of muscle growth vary highly from person to person. While gaining two pounds of muscle per month may be the average, some women are able to gain muscle up to three times as quickly (study).
Isn’t gaining weight that quickly going to cause fat gain? If you gain weight more quickly than you can build muscle, you’ll gain fat. That’s why it’s important to gain weight at the right pace. Also, keep in mind that if you want to maintain, say, a 20% body-fat percentage as you bulk up, that means that 20% of the weight that you gain can be fat without even raising your body-fat percentage.
Furthermore, the more muscle you gain, the better your insulin sensitivity will become, and the easier it will be to maintain a lower body-fat percentage in the future (study). This is one of the great advantages of building muscle.
Finally, Bret Conteras, PhD, known for being the top glute growth researcher in the world, has used our Bony to Bombshell transformations as examples of women being able to build a ton of muscle without gaining any noticeable fat.
So, yes, when gaining weight you can certainly gain fat, especially when doing it quickly. But is that going to actually make you fat? No. It’s not something you really need to worry about.
Is gaining that much muscle going to make you look blocky / bulky / increase your waist size? We have a lot of members trying to gain serious amounts of weight, but they aren’t necessarily trying to just get big, they’re trying to build an hourglass figure.
The muscles in your waist are small, the muscles in your shoulders are a little bit bigger, and the muscles in your hips are absolutely enormous—they’re the largest muscles in your body and have the most potential for growth. This means that as you build muscle, your waist should stay quite small, your shoulders will grow a little bigger, and your hips will explode in size.
Here’s how Ioulia’s proportions changed while following an overall strength program with only a slight emphasis on increasing her hip size and strength: