Rehabilitation after total knee arthroplasty (TKA) should consider control of postoperative pain and swelling, protection of the healing graft, restoration of full range of motion symmetric to the contralateral knee, strengthening of the muscles that stabilize the knee, hip, and trunk, enhancing neuromuscular control, and a gradual progression to functional activities that are required for return to the normal daily life. The effects of concomitant injuries and surgical procedures must also be considered in planning an individualized rehabilitation program. However, it is still unclear regarding the optimal exercise prescription after TKA. In the current study, the investigators plan to develop an exercise protocol and evaluate the result in a multidisciplinary approach, i.e. bone mineral density assessment. The exercise prescription consisted of cyclic exercise, aerobic exercise and resistant training exercise for first, second and third year, respectively. Cyclic exercise is advantaged safety and effectiveness of hydraulic resistance equipment, as well as the exercise can be quantitatively determined. Aerobic exercise is privileged by the cardiopulmonary endurance improvement, along with muscle strengthening in the associated muscle groups. Resistance exercise is specified for the indicated muscle groups, especially knee extensors, flexors, ankle plantar flexor and dorsi flexor in TKA reconstructed patients. The investigators hypothesis that using this cyclic exercise process can improve the body composition, muscle strength, bone mass density, level of oxidative damage indicators, gait performance, quality of life, knee joint range of motion, function of cardiopulmonary and fitness. This project will establish the scientific basis for rehabilitation protocol involving knee surgery.