Giving that same dosage of actual Dianabol to advanced trainees improves strength by only a few percent. Moreover, the androgenic-anabolic steroid protocol in question was just 70 mg of Dianabol per week.

These were advanced trainees already benching and squatting over 300 pounds (137 kg) before taking the fake steroids. In a famous study, simply telling people they were on steroids increased their strength gains by 321%.

People have lower expectations of women, even most women themselves underestimate what they can achieve physically compared to men.

Women have ~12% essential body fat to regulate their hormones compared to just ~3% fat in men.

Women have a genetically higher body fat percentage.

The 15% difference can easily be explained by 3 factors. The studied sports included Olympic weightlifting and powerlifting. Elite, natural female athletes have 85% as much muscle as elite male athletes. If you think this is all just silly theory from labcoats studying beginners, consider this. During this time, she won her pro card in Fit Body and Figure (yes, 2 pro cards) and took first place in her first pro show, the WNBF Pro-Am Central USA Natural Championships. I worked with Hayley Hirshland (now Hayley Yamanaka) for over 2 years. In fact, one study found that given the same level of muscle mass, women have a higher rate of muscle protein synthesis than men.

Women build just as much muscle protein after training and after meals as men. Research on protein metabolism comes to the same conclusion. Men start off with more muscle mass and more strength, but the relative increase in muscle size is the same between men and women. The only difference is the starting point. In fact, women gain as much size and sometimes more strength than men. Women gain the same percentage of muscle mass as men during strength training. Percentage wise, how much muscle can a woman build compared to a man? Does it scale with testosterone so that women can build only ~7% as much muscle as men? Is it about half? Before I explain this, let’s first look at how the natural muscular potential of women compares to that of men. There is truth to this, but the causality runs in the opposite direction. So the common recommendation in today’s fitness circles is that women should train like men and should expect not to see much muscle growth. The statistic that women have ~15 times less testosterone than men is often quoted to explain that as a woman, you can’t grow much muscle anyway. One look around you in the average gym makes it clear that getting seriously big is difficult even for men. People with a bit more understanding of exercise physiology realize that this is obviously nonsense. The general public thinks a woman that touches a loaded barbell will wake up the next day as the SheHulk. What can you achieve as a female lifter? There seem to be only 2 camps.

How do muscles grow scientifically