When people do exercise with their blood flow partly restricted, men’s muscles tend to swell more in absolute size than women’s, but when you look at how much they swell relative to their starting size, men and women are about the same.

Even though men and women, or different cuff sizes, cause different amounts of muscle swelling in absolute terms, when you adjust for how big the muscle was to start with, everyone swells about the same — so if swelling is what triggers muscle growth, these differences might not matter.

When using a thinner cuff to restrict blood flow during exercise, muscles swell more in absolute size than with a thicker cuff, but when you account for how big the muscle was to start with, both cuffs cause about the same amount of swelling.

After doing heavy weight training, if women who’ve never trained before use a tight band around their arm afterward, their arm muscles don’t get any thicker—but men’s muscles still grow normally.