Figure 1

Study design. The figure details the dates in which participants are assessed or receive intervention. After screening at baseline, participants pass three visits (Visits 1a-c) at the respective departments; that is, the Institute of General Practice for psychometric testing, the Department of Sports Medicine for movement-related testing and the Institute of Neuroradiology for the conduction of the magnetic resonance (MR) protocol. Participants fulfilling all inclusion criteria are than randomly allocated to two groups: the intervention group (INT) or the waiting control group (CON). In the INT group, participants start a 12-week individualised aerobic exercise programme on a bicycle ergometer whereas in the CON group they continue their used daily activity for another 12 weeks. After 12 weeks, participants are reassessed at the above mentioned departments (Visits 2a-c). Participants in the CON group can now decide to perform the exercise programme too. Follow-up ends at 24 weeks (Visits 3a-c).