High-Intensity Interval And Moderate-Intensity Continuous Training Improve Maximal Oxygen Uptake In Parkinson’S Disease Patients

Parkinson’s disease (PD) is the second most common neurodegenerative disease in the United States. Aerobic exercise training is a recommended lifestyle interventions for people with PD, but it is unclear whether an optimal exercise program exists. High-intensity interval training (HIIT) has been shown to improve 6-min walk performance more than moderate-intensity continuous training (MICT) in PD, but whether this is secondary to improvements in peak oxygen uptake (VO2peak) or gait mechanics was not assessed. PURPOSE: The current study tested the hypothesis that VO2peak would be increased to a greater extent after 10 weeks of HIIT vs MICT. METHODS: Twenty-eight participants with PD (11 females; 67 ± 7 years) were randomly assigned to complete 10 weeks of supervised HIIT (n = 15) or MICT (n = 13) comprising three exercise sessions per week. HIIT involved 10, 1-min bouts of cycling at ~90% peak power output, each separated by 1-min at 10% peak power output. MICT involved 30-50 min of cycling at 60% peak power output. An incremental cycling test to volitional exhaustion was completed pre- and post-training to determine VO2peak, the first ventilatory threshold, and respiratory compensation point. RESULTS: Respiratory exchange ratio at VO2peak pre- and post-training was 1.12 ± 0.13 and 1.11 ± 0.10 for the HIIT group and 1.08 ± 0.15 and 1.12 ± 0.12 for the MICT group, respectively. VO2peak was higher following training (MICT: 1.63 ± 0.59 to 1.75 ± 0.57 L/min; HIIT: 1.79 ± 0.57 to 2.07 ± 0.67 L/min; main effect of time, p < 0.001). The increase in VO2peak per kg body mass was not statistically greater in HIIT vs. MICT (Δ3.7 ± 3.7 vs 1.7 ± 3.2 ml/kg/min, p = 0.10). Power output at VO2peak was 15 ± 5 W higher following training in both groups (p < 0.01). Ventilatory threshold one (MICT, Pre = 1082 ± 372, Post = 1126 ± 331 ml/min, n = 11; HIIT, Pre = 1159 ± 91, Post = 1329 ± 201 ml/min, n = 13) and respiratory compensation point (MICT, 1492 ± 593, Post = 1568 ± 513 ml/min, n = 5; HIIT, 1791 ± 405, Post = 1986 ± 475 ml/min, n = 7) were unaffected by training (p > 0.06) or training x group (p > 0.33 for all). CONCLUSIONS: Ten weeks of exercise training improved VO2peak in PD patients. HIIT may have elicited a larger, clinically meaningful improvement in VO2peak compared to MICT, when considering that a clinically meaningful difference in VO2peak could be as low as 1.5 ml/kg/min. Parkinson Canada Pilot Project Grant (2018-00186)