Is it possible to gain 20-30 pounds of lean muscles in 8 month to a year?
You sure can, especially if you’re just now starting a lifting regiment, as you’ll see the quickest results at first. The year that I started lifting, I went from about 135 to about 160. However, in the four years since, I’ve gained slightly less than 30 pounds. I know these people had top-of-the-line, very expensive personal trainers, chefs, and dietitians, but Christian Bale gained about 100 pounds for Batman (of course, in his previous role, he was anorexic-looking), Adam Sandler gained about 20 pounds for You Don’t Mess with the Zohan, Matt Damon gained quite a bit of muscle for Invictus, there are tons of stories about pro athletes gaining a ton of muscle in one off-season, etc. Just make sure you’re eating right and pushing yourself enough but not too much and getting enough rest. I suggest you look at a good weightlifting site, like bodybuilding.com for more specific advice. Good luck!