Objectives: There is growing interest in the use of exercise in the treatment of depression. A number of randomized controlled trials (RCTs) have demonstrated a reduction in depressive symptoms with both aerobic and non-aerobic exercise interventions. This has been supported in a number of systematic reviews and meta-analyses. However, the heterogeneous nature of the exercise intervention trials makes determining the appropriate program variables (frequency, intensity, duration and type of exercise) difficult. Design: A systematic review was undertaken on all RCTs reporting a significant treatment effect of exercise in the treatment of depression. Methods: Studies were analyzed for exercise frequency, intensity, session duration, exercise type, exercise mode, intervention duration, delivery of exercise, level and quality of supervision and compliance. Study quality was assessed using the PEDro scale. Results: Five RCTs published since 2007 met the inclusion criteria and were subsequently analyzed. Most programs were performed three times weekly and of moderate intensity. All included trials used aerobic exercise, either treadmill or outdoor walking, stationary cycle or elliptical cross trainer exercise. Intervention duration ranged from four to twelve weeks. Both group and individual programs were shown to be effective in lowering the symptoms of depression. Some level of supervision is recommended. Conclusions: There is evidence for the use supervised aerobic exercise, undertaken three times weekly at moderate intensity for a minimum of nine weeks in the treatment of depression. Further research on the manipulation of program variables is warranted.