High-intensity interval versus moderate-intensity continuous cycling training in Parkinson's disease: a randomized trial.

Exercise training is recommended to improve the quality of life in those living with Parkinson's disease (PD); however, the optimal prescription to improve cardiorespiratory fitness and disease-related motor symptoms remains unknown. Twenty-nine participants with PD were randomly allocated to either 10 wk of high-intensity interval training (HIIT) ( = 15; 6 female) or moderate-intensity continuous training (MICT) ( = 14; 5 female). The primary outcome was the change in maximal oxygen consumption (V̇o). Secondary outcomes included changes in the Unified Parkinson's Disease Rating Scale (UPDRS) Part III motor score, Parkinson's Fatigue Scale (PFS)-16, resting and exercise cardiovascular measures, gait, balance, and knee extensor strength and fatigability. Exercise training increased V̇o (main effect of time, < 0.01), with a clinically meaningful difference in the change following HIIT versus MICT (Δ3.7 ± 3.7 vs. 1.7 ± 3.2 mL·kg·min, = 0.099). The UPDRS motor score improved over time ( < 0.001) but without any differences between HIIT versus MICT (Δ-9.7 ± 1.3 vs. -8.4 ± 1.4, = 0.51). Self-reported subjective fatigue (PFS-16) decreased over time ( < 0.01) but was similar between HIIT and MICT groups ( = 0.6). Gait, balance, blood pressure (BP), and heart rate (HR) were unchanged with training (all > 0.09). Knee extensor strength increased over time ( = 0.03) but did not differ between HIIT versus MICT (Δ8.2 ± 5.9 vs. 11.7 ± 6.2 Nm, = 0.69). HIIT alone increased the muscular endurance of the knee extensors during an isotonic fatigue task to failure ( = 0.04). In participants with PD, HIIT and MICT both increased V̇o and led to improvements in motor symptoms and perceived fatigue; HIIT may offer the potential for larger changes in V̇o and reduced knee extensor fatigability. The optimal exercise prescription to improve cardiorespiratory fitness and disease-related motor symptoms in adults with Parkinson's disease remains unknown. In a single-center randomized trial consisting of either 10 wk of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT), we found that both training modes increased V̇o, with a larger clinically meaningful difference following HIIT. Both exercise modes improved motor symptoms and subjective fatigue, whereas HIIT increased the muscular endurance of the knee extensors.