Happens all the time

This is manifestly untrue. I gained well over 15 pounds of muscle in only two months in US Army basic training.

I went from 135 pounds to 153 pounds from early September 1994 to late October of the same year. And yep, it was muscle — had my body fat ratio measured.

A more accurate sentence would read, “Nearly no women can gain 15 pounds of muscle in 3 months.”

I build muscle very quickly and even at my age I think I could still put on 15 pounds of muscle in 3 months if I trained like I did in the Army.

(At my largest in the Army, I was around 174 pounds with 8% body fat. But then, I worked out four hours a day, 5-6 days a week.)