Arnold Schwarzenegger continues to educate his fans on the nuances of nutrition. In Arnold’s Pump Club newsletter from June 9, 2026, he broke down whether women get less muscle from protein than men.
“It’s an old assumption dressed up as biology: men have testosterone, so women’s bodies turn protein into muscle differently. If you’ve ever treated your training as a rigged game because of it, or if you’re not sure of how much protein you need, this one’s worth a few minutes.”
Protein is the building block for muscle and is essential to workout performance. Arnold Schwarzenegger realized this during the prime years of his bodybuilding career. Before stepping away from the stage, he secured seven Mr. Olympia titles.
Ensuring protein intake comes with its fair share of challenges. But that’s just quantity; the sources we gravitate toward can also have a major impact on muscle protein synthesis (MPS). Though many would assume men reap the lion’s share of muscle from protein, Schwarzenegger explains why women can gain just as much.
Arnold Schwarzenegger Shares Whether Women Get Less Out Of Protein Than Men
Schwarzenegger looked at an MPS study where men and women engaged in heavy resistance training, then drank a whey protein shake. They examined the rate at which bodies turned new protein into muscle.
“After a hard workout, women build new muscle protein at the same rate as men, even though men’s testosterone levels are approximately 45 times higher in the hour afterward.”
“Researchers had men and women complete a single bout of heavy resistance exercise, then drink 25 grams of whey protein. Using an infused amino acid tracer and muscle biopsies, they measured the rate at which your body weaves new protein into muscle (also known as muscle protein synthesis).”
Overall, the study concluded that women’s muscle protein synthesis rose similarly to men:
“The men’s post-workout testosterone was significantly more than the women’s. But here’s the part that matters: the muscle-building response didn’t follow it. Synthesis rose just as much in the women, despite the lower testosterone.”
Though testosterone is highlighted for its influence on muscle-building, Schwarzenegger shared that mechanical tension coupled with protein matters most:
“Testosterone gets the credit as the master switch for muscle, but that’s not what matters most (and it’s not even close).”
The mechanical tension you create when you perform resistance training exercise and the amino acids from your meals flip on a signaling pathway inside the muscle itself. The pathway for growth first answers to the work you do and how close you train to failure, and then your nutrition supports that process. It’s not dictated by the hormones in your bloodstream.”
Additionally, he revealed two other trials that found resistance training paired with protein will improve strength regardless of gender.
“A meta-analysis of randomized trials found that pairing more protein with resistance training improves strength regardless of gender. And a 2025 meta-analysis on muscle growth found that women’s relative gains remain close to men’s. While men edge ahead in absolute size, the percentage gain from each person’s starting point comes out nearly even.”
“In other words, a smaller body needs fewer grams, not a different target for its size.”
Protein consumption is still a top priority for Schwarzenegger beyond the stage. In his seventies, he switched to a plant-dominant diet to support his blood pressure. He also credited plant proteins for their potential to lower cancer risks.
Thanks to a wealth of research, Schwarzenegger notes that women can utilize protein just as efficiently as men. On top of that, they could even reap similar muscle-building gains over time.
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