Life-style modification, particularly exercise and weight reduction, is a core component of the management of osteoarthritis. In this chapter, the evidence for the efficacy of exercise, weight reduction and footwear is reviewed. Caveats to the evidence and the areas where further research is needed are highlighted. Long-term adherence to exercise and weight reduction is a key predictor of response, and strategies for increasing adherence are reviewed. Our discussion focuses predominantly on knee OA, to which most of the evidence relates but refers to other sites where appropriate.