If youre doing a bowling or tennis game, then you need enough space to turn sideways, swing your imaginary backswing and then have enough room in front too so you can step forward. imagine yourself taking a somewhat modified motion that copies whatever imaginary sport you might be playing (WII SPORT DVD). If you're staying on the balance board, its a smaller circumference. But you don't want any sharp corners close by or a rug to trip over, etc. Tripping over furniture might help the young & agile, but for the rest of us, it'd be best to have no nearby obstacles that would leave bruises, break a rib, poke out the 'ole eye, you got it I believe. Note: There's a small raised platform sold by WII-related shops, on which you set the Balance Board, and that Step exercise (which you can do to any music, etc) takes less room. Just make sure you won't fall in any direction on something that will poke or break you. Good luck.