The Phase III SPARX3 trial (NCT04284436) is investigating the effects of moderate- and high-intensity aerobic exercise on disease progression in untreated patients with Parkinson’s disease (PD). Principle investigator, Daniel Corcos, PhD, Northwestern University, Chicago, IL, shares details of the multicenter randomized controlled trial. A total of 370 patients from 29 sites across the US and Canada will be randomized to moderate intensity (60-65% HRmax) or high intensity (80-85% HRmax) exercise 4 times per week for 18 months. Changes in the Movement Disorder Society-Unified Parkinson Disease Rating Scale (MDS-UPDRS) Part III score at 12 months will be assessed as the study’s primary endpoint. Striatal specific binding ratio, cognition, quality of life, and blood-based biomarkers of inflammation and neurotrophic factors will also be assessed. Adherence following study completion will also be investigated. It is hoped the trial will provide strong evidence to support the benefit of endurance exercise in PD, prompting better uptake in patients. This interview took place during the 2021 International Congress of Parkinson’s Disease and Movement Disorders.