Somebody told you your DNA might not allow you to improve your physique? Ahahaha, oh man please slap them and tell them to pull their head out their ass lol. ANYONE can improve their physique, and certainly everyone can get fitter, as that’s what the human body is built to do. Even if you’re a ‘hardgainer’ (thats what bodybuilder’s call skinny guys basically) you can definitely improve your physique through boxing training, I know this because I am one myself and it’s had a huge impact on me