Effects of Exercise Intervention on Executive Function in 90-day Head-Down Bed Rest

Exercise is commonly used as an intervention strategy to enhance individual executive function. However, its effectiveness in improving executive function under prolonged head-down bed rest (HDBR) conditions remains unclear. The objective of this research is to examine whether physical exercise can improve executive function under HDBR conditions. We conducted a 135-day HDBR study involving 36 participants randomly allocated to five groups: control group (C), aerobic exercise combined with low-intensity resistance training (E1), aerobic exercise combined with high-intensity resistance training (E2), aerobic exercise alone (E3), and resistance training alone (E4). These exercise interventions were conducted during HDBR conditions. Additionally, we assessed working memory and cognitive flexibility throughout the study, including baseline (-3d), three intervention period assessments (30d, 60d, 90d), and a post-assessment (+30d). Findings revealed that during the early stage (30d) of HDBR, the intervention combining higher intensity resistance and aerobic exercises (E2) significantly enhanced cognitive flexibility. Conversely, in the mid-stage (60d) of HDBR, resistance training alone (E4) demonstrated superior improvement in cognitive flexibility compared to other intervention modalities. In conclusion, this study provides experimental evidence on the alterations in individual executive function under simulated long-term weightlessness conditions and offers guidance on the implementation of exercise interventions at various stages of HDBR conditions.