An exemplary exercise device includes a deck, a track, and a ball. Opposing ends of the deck include foot supports. The track bulges upwardly from the deck to form a dome that receives the ball. With the ball and deck on the floor, a user balances herself on the foot supports and may move along multiple axes as the ball rolls on the floor. The user may (for example) pivot and rock the exercise device (as she balances herself), rolling the ball along the track while alternately touching the ends of the deck to the floor, or the user may twist the exercise device clockwise and/or counterclockwise. The exercise device allows for enhanced strength and cardiac training, in addition to balance training, as the user engages in motions and repetitions that may include rolling the ball in the track and contacting different portions of the deck with the floor.