Does Hypoxia Conditioning Improve Physical Fitness In Middle-aged And Older Adults? - Meta-Analysis

Aging is a primary risk factor for chronic diseases and impair physical and cognitive functions, leading to muscle atrophy. The loss of muscle strength, oxygen uptake, and decline in physical function will further reducing the quality of life. PURPOSE: Hypoxic conditioning has gained attention as a method to improve physical fitness in the middle-aged and older adults. A systematic review and meta-analysis of randomized controlled trials was performed to evaluate the effects of hypoxia in addition to exercise on physical fitness outcomes. METHODS: Embase, PubMed, Cochrane Library, and Web of Science were searched from inception to October 2023 (Prospero registration: CRD42023474570). Articles were eligible if the interventions consisted of exercise training approaches that were combined with hypoxia and if they reported measures of physical fitness. The Cochrane Evaluation Tool was used for risk of bias assessment with analysis were performed using the Review Manager. Subgroup analysis was performed to explore possible associations between the study characteristics and the effectiveness of the interventions. RESULTS: A total of 13 RCTs were included in the meta-analysis, with the mean (SD) age of subjects ranging from 42.1 (1.7) to 72.56 (3.57) years. Hypoxic conditioning have not induced greater changes on functional outcomes (SMD = −0.21, 95%CI, −0.66 to 0.24; p﹥0.05), maximal power output (SMD = 0.29, 95%CI, -0.17 to 0.76; p﹥0.05), VO2max (SMD = −0.39, 95%CI, −1.12 to 1.90; p﹥0.05). CONCLUSIONS: This study suggests that additional hypoxia may not improve physical fitness outcomes in the middle-aged and older adults comparing to equivalent training in normoxia.China Scholarship Council