Have you always had a lot of mass, but the body fat is pretty high? Like 16 or 17 percent, even as a football player back in the day? Would you need to cut down and start to build up muscle from there. Also having trouble getting leg stronger.What is the best way to go about gaining muscle mass and strengthening muscles?
Most importantly, cutting down before attempting to gain any more size is the best route to go. First it will make much easier to see your exact shape and what you need to improve. Secondly, when trying to gain mass, the amount of calories you will need to grow efficiently will put a small amount of water and body fat on you. Meaning, you might grow, but you're only going to become fatter. This will make it much harder to eventually lean out, if you ever choose to do so. If bodybuilding is what you love right now, you will want to do this.Leaning out is easy if you add a fat burning pill or legal steroid made for weight loss.
As far as legs, believing it is the football background that makes us desire to squat and lift large amounts of weight. Keeping in mind though, it is not always the best way to gain muscle size and muscle strength. Try really working on your form and upping your reps. Dropping the weight quite a bit and really cranking up the reps, as in 15, 20 and even 30. You'll have more growth out of your legs training this way. Because of the athletic background, you legs have a higher endurance than the average person. Therefore, you really have to work them hard to get some muscle growth.