A randomized controlled pilot trial assigned 24 people with mild-to-moderate Parkinson's disease to either moderate-intensity cycling or seated rest immediately after practicing a novel balance task across six weekly sessions. The cycling group showed 49% improvement from first to last session versus 29% in the rest group. Statistically significant group differences emerged in sessions 4 and 5, suggesting cumulative benefits of pairing cardiovascular exercise with skill practice. Exploratory analyses revealed that individuals with higher cardiorespiratory fitness (VO2peak) benefited most. The effect appeared driven by enhanced within-session online learning rather than between-session offline consolidation, contrary to the researchers' secondary hypothesis. These findings position post-practice cardiovascular exercise as a practical, low-cost tool for enhancing motor rehabilitation in Parkinson's disease.