I am a 19 year old male, 5' 7", 135 pounds. Up until last year I was focused solely on calisthenics as my body training and as a result of that I am extremely toned and lean but I have a skinny body. This year I've decided to start lifting weights and bulk up. The transition was relatively easy because I already had the strength for it but I feel like I haven't been putting all my effort into this new training plan due to a fear that I will gain to much weight (fat weight). My question really boils down to this: how do I gain muscle weight and mass while retaining my "toneness" of my body? (Asking both about the eating aspect and the training aspect) Thank you!
How many calories a day are you taking in now? Let's go with 2000 calories.
If you want to gain some muscle mass, you need to shift your calories to include more proteins (beef, chicken, fish) and good fats (avocados, nuts, olive oil).
But, if you are lean now, that will not be enough.
Add an extra 100 calories to your daily diet. 100 calories is minimal, and focus those calories on protein for muscle growth.
Give yourself time to see how your body responds to the extra calories. You are either going to apply that to muscle or you will be taking in too many and storing some of your total calories as fat.
If you are staying lean the way you want, you can add another 100 calories.
Again, give your body time to see how it responds to the extra intake.
Once you start noticing that your body is adding fat, cut back a little on your calories to a total calorie count that you can maintain.