I am curious if anyone who has knowledge on this can answer this.

Bob, who trains 5 days a week, has a maintenance of 3,000 calories and remains at 10% bodyfat.

If Bob wanted to put on muscle mass, he would need to eat more carbohydrates and protein, correct? As this fuels the growth? Let’s say he is now at 3,300 calories per day

However if Bob started to eat more, he would be in a surpluss and whilst gaining muscle, put on bodyfat.

If Bob decided to include cardio into his program and now burnt 300 calories more per day, bringing him back at a maintenance for energy consumption and out put, would Bob still get the benefits of the extra protein and carbs to build muscle mass he is now having and stay at 10% bodyfat? Or would he be in exactly the same situation as he was before just at a higher maintenance?