I’ve been going to the gym for almost 9 months 3-4 times/week. I am really fit now and my muscles are defined. But how can I build mass?

People don’t actually see that I go to the gym because I don’t have gains. My arms look like a football player’s (soccer) though, which is not that bad. I am 5’8 (177 cm) and 154 lbs (69 kg). Now I have a quite defined jawline. If I gain weight, I have larger arms, but my face looks puffy. Some people actually say I’m in a very good shape, but others say I’m not athletic.

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3 d
Imagine my body kinda looks like Phil Foden’s
I’ve been going to the gym for almost 9 months 3-4 times/week. I am really fit now and my muscles are defined. But how can I build mass?
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