I've been lifting weights for the past 6 years or so. Since starting finasteride i've certainly bulked up and gained a little wieght, not so much muscular though, my strength hasnt spiked up any noticable bit from it either. I don't think I've gotten weaker though... either way, it's not gona make you into a feeble man-woman, if it makes gaining muscle harder, it's certainly not a significant amount.