Can lifting heavy weights make you bulky? Not if you’re a woman.

woman weight lifting

We combine personal experience, three expert opinions, and a healthy dose of scientific research to explain why most women simply won’t get bulky from lifting weights.

Too busy to read the whole article? [1600 words, a 7-minute read] Here are the takeaways:

  • Women lack the right balance of hormones, testosterone and growth hormone, to put on muscle mass the way men do.
  • When women start lifting, they complain of getting bulky because of a combination of fluid retention, inflammation and plain old “feeling ‘swole”
  • Even if you lift enough to put on some weight, many women [and men] prefer the change in body composition.
  • Supplements. Men and women react very differently to pre-workout supplements. Find out what supplements women can use to booster their performance in the gym.

irst off, let me explain my perspective. I took up competitive weightlifting in my 30s and ended up being pretty good at it—in 2011, I broke the American Powerlifting Association record for the squat in my weight class. I tell you this not to brag, but to explain that I wrote this article not as an outsider, but as someone who has actually lived through the training and science we’ll dive into below. (I also ended up overtraining my way into an ugly injury, but that’s another story for another day — stay tuned.)

When I started training, I never got bulky and I never needed to intentionally increase my mass. In fact, I dropped a pant size or two while I traded some cushy padding for clearly defined muscle. But one woman’s experience does not fact make. So I turned to a couple of experts for their input.  Dr. Krista Scott-Dixon, founder of Stumptuous.com, is the Lean Eating Program Director at Precision Nutrition. And Jerry Handley is a West Virginia University strength coach who works primarily with female athletes.

Women can get bulky, but it’s very difficult

Let’s get right to it. “It is possible for women to get bulky,” Jerry said. “But it is highly improbable. They don’t hit the perfect storm of variables needed.”

How improbable are we talking? “Less than 1/10 of one percent of women are going to hit it,” he said. “It’s going to take a huge amount of consistent long term effort, consistently applying yourself to training – not just recreational [working out]. And it’s going to take a big nutrition push.”

Simply put, women aren’t built the same way as men are and we do not gain muscle mass as easily. According to Jerry, although “the hormonal situation while lifting causes the same triggers in men and women,  men elicit – minimum –  10 times more anabolic hormones than females do, particularly testosterone, which is what actually encourages muscle growth. Even though females can train just as hard and put in the effort to eat, their actual response is much much smaller and slower than a guy’s.”

Or, as Krista put it, “men’s muscles are bathing in a testosterone soup.”

Let’s talk more about those anabolic hormones.* Two things are going on here. Testosterone is stimulated when you lift heavy. What does heavy mean? Jerry defines it as “anything they can do a max of 6 times.” That’s the rep range, according to Jerry, that elicits the highest testosterone. When you “feel the burn,” on the other hand, doing higher volume or spending more time under tension, that’s when you’re stimulating growth hormone. “Women are typically worried about lifting heavy because they think it will make them big but really, while the testosterone will help the muscles repair, it’s not enough to make the muscles much bigger,” Jerry said. “Especially when they’re dieting, lifting heavy can help them retain their muscle mass and retain their strength.”

*Hormones are naturally-occurring chemicals that trigger organs and muscles to perform actions within the body. There are two basic types of hormones involved in normal metabolism: anabolic hormones generally “build up” tissues while catabolic hormones break down tissues for energy. This is a really simplified explanation; we’re working on a full-blown article on hormones and we’ll link it here when it’s ready.

Since few women actually get bulky from lifting heavy, why do so many of us think we do?

Aside from the  very small percentage of women whom Krista called “genetically gifted, hormonally ready easy gainers,”  what’s with all the cries of “I get big!”? Even Jerry sees it with his college athletes. “When it’s the first time they’ve done serious weight training, at least half of them are worried they’ll get bulky,” he said.

Culprit #1: Self Perception

“The first thing to remember,” Krista told me, “is that our self-perception is generally inaccurate. We are all very poor judges of ourselves. I’ve had women swear they were growing giant biceps, and flex for me, and I can’t see anything. But they FEEL like their guns are getting swole. So that’s their reality. The same is true of the FEEL of body composition. Few people truly have the self-awareness and accurate perception to gauge body changes.”

Culprit #2: Fluid retention

Krista explained: “In the early stages of training, you get a lot of inflammation and the muscles draw in glycogen and water. (By way of simplified explanation I say that muscles are “fluffing up” although that is not really what happens; it’s just a handy visual.) The fluid retention and inflammatory process is what causes the stiffness and soreness, same as what happens if you sprain your ankle and it swells up. So, women will train for a couple of weeks and swear they have ‘bulked up’ — and perhaps they have, but it’s not muscle.” And that means it’s not permanent.

Culprit #3: Eating more

“Many women consciously or unconsciously eat more to compensate for an increased training load,” Krista continued. “Some are just hungrier; others deliberately eat more because they think they need it to support their training. More food = more mass… but not always muscle. Most people don’t realize how much body fat they’re actually carrying. I like to show an MRI cross section of an average woman’s thigh to give them the idea. The light/white area is fat; the dark/dense area is muscle. You can see the bone as a circle in the middle.”

Sort of #4: Muscle gain… eventually

“Now, I really do hate to put a figure on it, but we are probably looking at no more than 1-2 lb/month of lean mass gain on average, tops,” Krista told me. “Even 18 year old boys don’t add as much muscle in a short time as some women swear they do.”

Jerry agreed. When you’re new to working out “your system hasn’t learned how to use the muscle fibers enough to create the muscle damage which creates growth. It’s almost completely nervous system,” he explained. “They may look more toned but actual muscle growth is almost impossible in the first few months.”

To sum it all up, “I think what women are often responding to is a different feel rather than an empirical reality,” Krista said. “The body does feel different… it’s just that their interpretation of why that feels different (i.e. the assumption that it’s muscle, and not fluid retention, which is much more probable) is often incorrect. The only way to truly know what’s what is to get regular, accurate body composition measurements. Otherwise it’s just speculation and rampantly imprecise self-perception.”

What actually does happen when women lift heavy?

When Jennifer Hudy‘s boyfriend showed her an article from Nerd Fitness with before and after photos of a girl who lifted, she was heavier in the ‘after’ photo. “She was no longer skinny-fat; she was quite fit,” Jennifer said. “I had never heard of skinny-fat but then realized that was exactly what I was. My build was skinny, but just skinny and nothing more. I envied her body and wanted to look like that!”

Using The New Rules of Lifting for Women program, Jennifer “ended up gaining eight pounds in six months. To see the scale going up was quite intimidating, but since I never had a weight issue it really didn’t bother me too much because I liked the way my body was shaping up.  Not only was my body significantly changing for the better, but my attitude about myself and my self-confidence skyrocketed.”

At the end of the day, lifting weights will change your body. But that’s the whole point, isn’t it?

It feels like a cop-out to say it, but the changes in appearance induced by exercise will be different for each woman. Once again, hormones play a critical role. “Some women with healthy levels of estrogen and progesterone will see body recomposition that reinforces the hourglass shape,” Krista said. On the other hand, “many powerlifters notice that their waist thickens–not from fat, but from the increased mass and density of the spinal erectors, which are powerful spinal support muscles required for a strong deadlift. Many women in upper-body-demanding activities (such as boxing or rowing) may find their bra size changes as their back muscles develop.”

And that’s just what we can see going on. For me, my bone density shot off the charts. Like Jennifer, so did my self confidence. Once you know you can take on a freaking intimidating weight, things that used to worry you seem a lot less scary.

How does lifting heavy compare to low-weight-high-reps?

So I think we’ve made a good case for why lifting heavy weights can help transform a woman’s body without making her get bulky. But, there’s an inherent risk to getting started with weightlifting. Plus, there’s the cost of weights, a coach to correct your form, etc. Is it worth it?

Without going too much down the rabbit hole, there does seem to be some evidence that traditional workout regimens for women actually do more harm than good.

When I asked Jerry about this, he told me “The idea of … doing higher reps and smaller weights [has] pretty much been shown over and over that it’s a crappy idea. It is completely against what the body actually does.” Here’s why: “If you do high volume and cardio and take in lower calories you’re using too much energy [thereby] encouraging your body to break down muscle mass.” And if you’re body isn’t producing the testosterone necessary to put on muscle, any excess calories you intake after a hard workout are more likely to be stored as fat.

We’ll go into loads more details on specific workouts in future articles, but I thought Jerry’s explanation was worth sharing.

Your next action: get started

Here are some ways you can get starting weightlifting for body recomposition. We’ll update this section as we find more resources and as you leave us comments below.