Arnold Schwarzenegger has been saying the same thing for over 40 years. Women belong in the gym, and they don't just survive there. They thrive.

The bodybuilding legend and former Governor of California restated that belief in a recent Instagram post on his account.

"I've been saying it for years: women thrive in the gym," stated part of the caption.

The Instagram clip traces back to an appearance on The Tonight Show with Johnny Carson, where he directly tackled one of the biggest fears keeping women away from weights at the time: the belief that lifting would make them bulky.

He pushed back with straightforward physiology. Women carry more fat cells and less muscle-building capacity than men due to hormonal differences, Schwarzenegger explained. That means resistance training would firm and shape the body rather than pack on large muscle mass.

The appearance mattered because of the era it happened in. Heavy training was still widely seen as a male-only pursuit, and Schwarzenegger used one of the biggest platforms in television to tell women otherwise. He framed the weight room as something that could reshape their physiques for the better, not something to fear.

Now, decades later, new research has come out that may change the way people think of muscle building for women.

Do men and women build muscle differently?

This has been a very polarizing question, and the answer to this might surprise you. According to new research, neither gender has the edge.

As published by Arnold’s Pump Club, a review of 27 studies, covering men and women between ages 18 and 50, found that men and women gain muscle equally well when the numbers are adjusted for genetic variables. 

Researchers looked beyond just training status, factoring in muscle fiber type and body composition differences, including men's tendency toward more upper body muscle.

Men can still gain more total muscle overall. But the rate of muscle growth between genders is nearly identical once that genetic ceiling is factored out.

The takeaway matters regardless of gender. Resistance training delivers benefits that go far beyond aesthetics. This helps people live longer, sleep better, fight disease, strengthen the heart, and improve how the body processes blood sugar.

The path to results just depends on the goal. Building significant size comes down mostly to nutrition. Getting lean and strong comes down mostly to training consistency.

Do you think Schwarzenegger's early advocacy helped shift the culture around women and weightlifting?

Follow Bodybuilding Bros for more.

Written by

Zaid Quraishi

Edited by

Zaid Quraishi