Purpose: To systematically review studies assessing (1) psychometric properties of the maximal oxygen uptake (VO2max) test in PD, (2) VO2max levels in persons with PD (pwPD) compared to healthy controls (HCs), and (3) reported VO2max associations in PD.
Materials and methods: Six databases were searched. Descriptive data synthesis was used to summarize psychometric properties and reported VO2max associations. The VO2max means and test end-criteria were calculated using linear mixed models. Simple linear regression was used for associations.
Results: The review included 25 studies. Psychometric properties of the VO2max test, reported in one study, showed intraclass correlations of 0.90-0.94 for VO2max. Thirteen studies reported test end-criteria, with only mean respiratory exchange ratio (on medication) and percentage of predicted maximal heart rate (off medication) fulfilling standardized minimum values for the VO2max test. The VO2max was comparable between pwPD and HC as well as between different PD-medication states. Associations between VO2max and age, sex, and fatigue were reported.
Conclusions: In mildly to moderately affected pwPD, limited evidence exists on the psychometric properties of the VO2max test and end-criteria were sparsely reported. Surprisingly, VO2max was comparable between pwPD and HC as well as between different PD-medication states, and only age, sex, and fatigue were associated with VO2max. Implications for rehabilitationIn mildly to moderately affected persons with PD (pwPD), only one study has examined psychometric properties of the VO2max test, reporting excellent test-retest reliability.A general lack of consistency on how to measure and report VO2max end-criteria was observed, but when reported, the end-criteria were most often not met.No difference was found in VO2max between mildly to moderately affected pwPD and HC, or between pwPD across different medication states.The identified negative association between VO2max and fatigue suggests aerobic exercise as a potential symptomatic treatment of fatigue when rehabilitation professionals are treating pwPD.
Keywords: Clinical exercise physiology; exercise therapy; kinesiology; neurological disorder; physical activity; training.