Boyd Swinburn, MB, ChB, FRACP, MD, Professor, Centre for Physical Activity and Nutrition, Deakin University, Melbourne, Victoria, Australia.
Richard Sager, BHlthSc (N&D), APD, Public Health Research Fellow, Greater Green Triangle University, Department of Rural Health, Deakin University, Warrnambool, Victoria, Australia.

Regular physical activity in older populations reduces the risks of cardiovascular diseases, diabetes, osteoporosis and falls and also improves mental health. Some programs of written exercise prescriptions by general practitioners have been shown to significantly increase physical activity levels over the medium-term (six to 12 months). Increasing the confidence and skills of general practitioners to prescribe and monitor exercise programs is important. However, the more challenging barriers to the widespread uptake of exercise prescription programs are the structural and economic constraints within general practice, as well as the competing promotion of prescribing pharmaceutical products. Implementation research on overcoming these barriers is urgently needed.
Key words: exercise prescriptions, general practitioner, health gains, training, barriers, health promotion.