Many chronic diseases and illnesses are caused by the lifestyle, including the physical activity habits, of an individual. As such, consistent high levels of exercise should be encouraged across the lifespan, to limit the risk of developing one of these conditions and allowing for healthy aging to occur. Exercise prescriptions that encourage high completion and adherence rates in an independent manner and improve health related outcomes should be provided to individuals. To date, no review has identified optimal prescriptions of exercise to achieve this in sedentary middle-aged adults and this is important, given the higher risk of developing illnesses in this population as they age. This review examines the effects prescriptions of self-directed (SD) exercise has on adherence and health related outcomes in sedentary middle-aged individuals in good general health currently and aims to identify the most suitable forms of planned SD exercise that can be carried out independently. A systematic search of the electronic database PubMed was conducted. Randomised controlled trials published in English between February 2007 and February 2017 examining healthy, sedentary middle-aged participants only were included. Studies were critically appraised using the PEDro scale and data were presented on standardised tables. Twenty-one articles examining different aerobic activities, combined training and non-traditional exercise prescriptions were included. This review summarised in detail the effects SD exercise interventions had on sedentary middle-aged individuals alongside the adherence to the prescriptions. SD exercise was seen to be beneficial for improving metabolic outcomes physical characteristics, cardiorespiratory fitness and functional measures.