Sage

I think that getting bigger muscles has more to do with the weight you're lifting than what you're sitting on. I just recommended it as a subsititute weight bench, because while you're doing your reps with the dumbbells, you're using stabilizing muscles in your body that don't normally get used- it's like swimming kinda, it hits all those little muscles that help your body along on a day to day basis.

I know that pilates uses just the ball and body weight to be "toned," but seeing as how you want to bulk up a bit I suggest dumbbells and sitting on the ball.

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