Exercise for patients with osteoarthritis should be divided into two categories. Proper and appropriate exercise can prevent, delay and slow down the process of osteoarthritis. Beneficial exercises include swimming, walking, bicycling, supine straight leg raises or resistance training and non-weight bearing joint flexion and extension activities. Incorrect excessive exercise can aggravate osteoarthritis. Harmful exercises are those that increase joint torsion or overload the joint surfaces, such as climbing hills, stairs or squatting and standing activities.