Author(s): KALVA-FILHO, C., FARIA, M., ANDRADE, A.X., CURSIOL, J.A., QUEIROZ, V.O., BARBIERI, F.A., Institution: UNESP, Country: BRAZIL, Abstract-ID: 2534

INTRODUCTION:
Inter-effort recovery hypoxia (IEH) consists of the application of reduced oxygen availability during recovery periods within exercise sessions. This approach may combine the well-established benefits of exercise with hypoxia-induced adaptations (e.g., improvements on dopamine metabolism), representing a promising adjunctive strategy for people with Parkinson’s disease (PwPD). Previously, we investigated the acute effects of IEH during treadmill sessions, demonstrating that the gait improvements are maintained, without any negative effects on postural stability, hand dexterity and functional mobility in PwPD. However, no studies have investigated i) the cumulative effects of repeated IEH exposure over time, such as three sessions per week (i.e., a typical microcycle applied in PD rehabilitation), or ii) its effects on gait asymmetry – a factor related to an increased fall risk. Thus, our objective was to investigate the cumulative effects of three consecutive IEH sessions on gait asymmetry in PwPD.
METHODS:
This study used a randomized, counterbalanced, placebo-controlled design. Twenty-one individuals with PD (Hoehn & Yahr = 2 ± 1; UPDRS-III = 22 ± 8 points) completed two microcycles, each consisting of three multimodal training sessions. Participants were exposed to hypoxia (TM-IEH) or placebo (TM-PLA) during the recovery periods between exercise stimuli (i.e., 10 min exposure + 10 min balance exercises; 5 min exposure + 10 min strength exercises; 5 min exposure + 10 min resistance exercises). During exposure periods, participants wore bidirectional masks connected to hypoxia generators (Sierra-100; Hypoxico), allowing different oxygen fractions (TM-IEH = 12.5%; TM-PLA = 20.9%). Spatiotemporal gait parameters were assessed before the first session and immediately after the third session using the GAITRite system (200 Hz). The asymmetry index (percentage difference between lower limbs) was analyzed using Friedman’s test, considering condition (TM-IEH vs. TM-PLA) and time (baseline vs. post) (p < 0.05).
RESULTS:
No significant effects were observed for step length, step time, swing time, or single support time asymmetry (p > 0.230). Although a significant main effect was detected for stance time asymmetry (p = 0.037), post hoc comparisons did not reveal significant pairwise differences. Double support time asymmetry after TM-PLA was significantly higher than the values observed before TM-IEH (p = 0.026).
CONCLUSION:
These findings suggest that IEH may mitigate the increase in double support asymmetry observed after a multimodal training microcycle in PwPD. However, gait asymmetry was assessed immediately after the microcycle, which includes the acute effects of the third session. Therefore, future studies should investigate whether the effects of IEH persist after a longer recovery period (e.g., 24 h). FAPESP (nº 23/06865-5 and 22/02971-2)