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Lifting Heavy Won’t Make You Bulky—Here’s What It’ll Do Instead

Debunking the myth of “bulk” once and for all.

Tonal Coach Ash Wilking

When you think about women lifting heavy weights, do female bodybuilders with big, bulging muscles come to mind? Well, it’s time to rethink that image. For too long, this myth—which is not supported by science—has dominated the conversation. It’s led women to avoid the type of training that will actually help them achieve their goals of looking lean, shifting their body composition, and feeling strong. 

Tonal coach and certified personal trainer Ash Wilking wants to change this narrative. For Wilking, lifting heavy and gaining strength has improved her self-image and confidence. “When we look in the mirror and feel strong, that allows us to see ourselves in a different way,” she says. 

Read on to learn more about how heavy lifting really affects women and how you can maximize the benefits of resistance training.

Does Heavy Lifting Make Women Bulky?

“​​Unless you are eating a lot and training really, really, super hard specifically to put on mass, you’re not going to get bulky,” says Stacy Sims, Ph.D., a female physiology expert and Tonal advisory board member. 

Sims says this myth likely dates back to the 1980s when the idea of women lifting weights was tied to extreme examples like the Ms. Olympia competition. For female bodybuilders, though, putting on mass is a full-time job. 

Gaining mass isn’t easy for anyone. Even men have to optimize their training and protein intake to gain the smallest amount of muscle, but it’s particularly difficult for women because of their hormonal makeup. 

Testosterone is an anabolic hormone that is responsible for muscle growth, and women produce far less testosterone than men.  While estrogen plays a similar role in women’s bodies, Sims explains that estrogen is less effective in muscle building because its levels fluctuate throughout the menstrual cycle, while testosterone levels in men are always present in a steady state. The drop off in estrogen is why post-menopausal women find it even more challenging to gain and maintain muscle.

Additionally, the female sex hormone progesterone has a negative effect on muscle growth. “Progesterone’s whole job is to break things down to provide building blocks to build a really lush endometrial lining [in the uterus],” says Sims. She explains that in the days following ovulation, progesterone surges and inhibits muscle growth by diverting carbohydrates and amino acids away from muscle tissue and toward creating a glycogen-rich endometrial lining for a fertilized egg. 

Along with hormonal differences, women also have a higher percentage of slow-twitch muscle fibers and a lower percentage of fast-twitch muscle fibers compared to men. Slow-twitch fibers, which are more fatigue-resistant and active in endurance exercise, are naturally smaller than their fast-twitch counterparts, which produce powerful force but fatigue quickly.

What Happens When Women Lift Heavy?

While heavy lifting won’t make you bulky, it will promote healthy bone density, which is especially important for women as they age, speed up your metabolism, and help burn more fat. Because muscle is such a powerful calorie burner, increasing your muscle mass is one science-backed key to getting lean.  

“When you’re building muscle, it often burns more calories than if you were just doing cardio,” says Wilking. After an intense workout, the body burns extra calories for hours afterward as it recovers and returns to a resting state. This effect is called excess post-exercise oxygen consumption (EPOC) and according to one study, it is especially powerful after resistance training.

“It’s a fun benefit. You get to work out for a short amount of time, and the rest of the day while you’re doing your emails or just sitting on your couch, your muscles are literally burning those calories,” she says. 

“When you’re building muscle, it often burns more calories than if you were just doing cardio.”

– Tonal Coach Ash Wilking

Besides burning off the fat you can see on your body, increasing lean muscle mass also reduces the amount of visceral fat that surrounds your organs and is linked to heart disease and high cholesterol. 

Resistance training also strengthens your tendons and ligaments. These are essential for moving better throughout everyday life or when playing a sport and can protect joints from injury. “Even if it’s just being able to enjoy our day-to-day without any pain, having strong muscles means healthy ligaments and tendons, which means healthy joints,” says Wilking.

How to Get Lean, Not Bulky

To unlock all the benefits of resistance training, you’ll want to incorporate heavy lifting into your routine. As explained above, this type of training is essential to building lean muscle and improving body composition. Diet plays a role, as well. To fuel your training and maximize your lean muscle gains, it’s essential to eat enough protein. Aim for 20 to 30 grams of protein post-workout.

How you structure your workouts makes a difference, too. Including high-intensity training along with your lifting ensures you’ll be balancing strength gains with metabolic conditioning. 

Keeping your heart rate elevated with short rest periods between exercises also promotes metabolic activity without creating additional muscle mass. “As soon as you put any kind of cardiovascular work in, then you’re down-regulating the ability to put on lean mass,” says Sims.

Best Tonal Programs for Building Lean Muscle

Shaped and Shredded: Maximum Burn – Coach Ash Wilking

Shaped and Shredded: Maximum Burn - Coach Ash Wilking

Wilking’s newest Tonal program incorporates heavy lifting with metabolic conditioning to build lean muscle while burning fat. Through supersets and drop sets using Tonal’s Burnout Mode, the intensity stays high throughout the workouts.  “We’re tapping into that metabolic response when we lift these weights because our goal is going to be [increased] work capacity,” says Wilking. Improving work capacity boosts endurance and allows you to work out more efficiently. 

The program incorporates strength-building compound lifts, cardio conditioning, accessory exercises, and core work. “There is a heavy emphasis on glute and core work in this program,” says Wilking. “Big muscles burn lots of calories and our glutes are the biggest muscles in our body.” 

Shaped and Shredded – Coach Gabby Sansosti

Shaped and Shredded - Coach Gabby Sansosti

The first program in the Shaped and Shredded series is already a huge hit among female (and male) Tonal members. The program includes heavy lifts, focused core work, and explosive cardio bursts for a full-body transformation. 

Lean Machine Bootcamp – Coach Nicolette Amarillas 

Lean Machine Bootcamp - Coach Nicolette Amarillas 

As its name suggests, this program offers a mix of heavy lifting with cardio moves to improve body composition by promoting fat loss and stimulating lean muscle development.

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