A portable exercise device includes a pedal spaced away from and pivotably connected to a base and having a neutral position relative to a pivot axis. The pedal is configured to rotate about the pivot axis in a first direction toward the base and in a second direction, opposite the first direction, toward the base. The device also includes a resistance mechanism configured to exert a force on the pedal about the pivot axis in a direction opposite to the respective direction of rotation of the pedal. The device is movable between an open, in-use configuration, where the pedal is disposed in the neutral position to receive a foot and spaced away from the base, and a closed configuration, where the pedal is adjacent the base.