The relation of exercise to osteoarthritis is one of great interest and importance. In this paper, we review two recent studies. One reported that older individuals with normal knee and hip joints who jog for recreational activities do not have an increased risk for the development of osteoarthritis in weight-bearing joints. However, in another case-control study of women with hip osteoarthritis, the risk of hip osteoarthritis increased twofold with high levels of participation in recreational activities before the age of 50 years and fourfold for women with high levels of sporting activities and occupational physical loads. Therefore, participation in certain types of sporting activities and occupations that increase loading to the hip joint before the age of 50 years may be associated with an increased risk of hip osteoarthritis. However, recreational jogging in individuals 60 or more years of age with normal knee and hip joints does not increase the risk for the development of osteoarthritis. These studies add to our knowledge base regarding lifetime and current risk factors for the development of knee and hip osteoarthritis from exercise.