I'm 33 years old and I've trained lightly on and off for several years. I boxed not long ago - and I liked to stay light - so I haven't done much heavy lifting.. I broke my foot in March and I'll never box again. So.. At my age, approximately how much muscle could I put on in a year, naturally? I'm guessing 10 pounds.. I've never had trouble gaining weight. I don't have the greatest genetics, but I can gain weight easily.