Dear Priya,
My dogs use to be like that. Atleast yours is running in and out. I stay in a flat and my dogs use to bring the house down with their playing. But now my Ronnie is 6 and kelly 4, (both poms) they have sobered down. But once in a while they do get into the play mood. I take them to the terrace once in a while and throw the ball and aks them to run.
But I think it is just a phase and once they start growing older they just stop playing.
Regards,
Uma