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

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) (n = 15; 6 female) or moderate-intensity continuous training (MICT) (n = 14; 5 female). The primary outcome was the change in maximal oxygen consumption (V̇o_2peak). 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_2peak (main effect of time, P < 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^-1·min^-1, P = 0.099). The UPDRS motor score improved over time (P < 0.001) but without any differences between HIIT versus MICT (Δ-9.7 ± 1.3 vs. -8.4 ± 1.4, P = 0.51). Self-reported subjective fatigue (PFS-16) decreased over time (P < 0.01) but was similar between HIIT and MICT groups (P = 0.6). Gait, balance, blood pressure (BP), and heart rate (HR) were unchanged with training (all P > 0.09). Knee extensor strength increased over time (P = 0.03) but did not differ between HIIT versus MICT (Δ8.2 ± 5.9 vs. 11.7 ± 6.2 Nm, P = 0.69). HIIT alone increased the muscular endurance of the knee extensors during an isotonic fatigue task to failure (P = 0.04). In participants with PD, HIIT and MICT both increased V̇o_2peak and led to improvements in motor symptoms and perceived fatigue; HIIT may offer the potential for larger changes in V̇o_2peak and reduced knee extensor fatigability.NEW & NOTEWORTHY 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_2peak, 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.