how do I keep it?

[cengiz]

OK I gained some mass and look better. But when the lessons begin, I do not have much time to exercise. So how do I keep my current "OK" body mass and shape?

[Gibblets]

keep working out

[samueljrusso]

OK I gained some mass and look better. But when the lessons begin, I do not have much time to exercise. So how do I keep my current "OK" body mass and shape?

work out your maintenance level calories and eat that

and yeah keep working out when you can

[Beast]

Weight lifting provides the stimulus for muscle growth. When you continuously challenge a particular muscles with loads it is unaccustomed to, it will adapt by growing larger or improving neuromuscular (nervous system) efficiency. When you stop working out, your body no longer senses the need to maintain the increased strength or muscle size which was the result or training.

I sounds to me like you just want to maintain what you have and not necessarily grow any bigger. If you do not have a lot of time, you could try 2 full body workout a week, like on Monday and Thursday. Obviously you would have to find the volume that will let you keep your gains.