Abstract: Portable exercise apparatus adaptable to fit a chair is provided. The apparatus comprises, in combination: (1) a back support removeably attachable to the backrest of a conventional chair; (2) at least one elongate extension member removeably and adjustably affixed to the back support such that the extension member extends through a point of reference located at a desired height on an imaginary vertical line which essentially bisects the backrest of the chair, the extension member extending through the point of reference and outwardly therefrom within a substantially vertical plane containing the line, the plane being parallel to and adjacent to the backrest of the chairs the outward end of the extension member having attached thereto, (3) a resistance mechanism to create resistance against movement, the resistance mechanism being engageable by a limb of a person when sitting in the chair.