The cyclical lower extremity exercise for Parkinson’s trial (CYCLE): methodology for a randomized controlled trial

BACKGROUND: Motor and non-motor impairments affect quality of life in individuals with Parkinson’s disease. Our preliminary research indicates that forced exercise cycling, a mode of exercise in which a participant’s voluntary rate of exercise is augmented on a stationary cycle, results in global improvements in the cardinal symptoms of Parkinson’s disease. The objective of the Cyclical Lower Extremity Exercise (CYCLE) trial for Parkinson’s disease is to determine the effects of forced exercise cycling on motor and non-motor performance when compared to voluntary rate cycling and a non-exercise control group. Additionally, we plan to identify any associated changes in neural activity determined by functional magnetic resonance imaging. METHODS/DESIGN: A total of 100 individuals with mild to moderate idiopathic Parkinson’s disease will participate in a single-center, parallel-group, rater-blind study. Participants will be randomized 2:2:1 into a forced exercise, voluntary exercise, or no-exercise control group, respectively. Both exercise groups will cycle 3 times per week for 8 weeks at identical aerobic intensities for 40 minutes, but participants in the forced exercise group will cycle 30% faster than their voluntary rate by means of an augmented motorized bicycle. Neuroimaging, clinical, and biomechanical assessments of motor and non-motor performance will be made at baseline both ‘on’ and ‘off’ medication, after four weeks of exercise (midpoint), end of treatment, 4 weeks after end of treatment, and 8 weeks after end of treatment. DISCUSSION: CYCLE trial will play a critical role in determining the effectiveness of two different types of aerobic exercise, forced and voluntary, on motor and non-motor performance in individuals with Parkinson’s disease. Additionally, the coupling of clinical, biomechanical, and neuroimaging outcomes has the potential to provide insight into mechanisms underlying change in function as a result of exercise. TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT01636297.