Effects of Short-Term Normobaric Hypoxic Walking Training on Energetics and Mechanics of Gait in Adults with Obesity.

The aim of this study was to compare the effects of short-term hypoxic versus normoxic training at preferred walking speed (PWS) on energetics, mechanics, efficiency, and metabolic risk markers in individuals with obesity. Twenty-three subjects with obesity performed nine 1-hour sessions at PWS under hypoxia (3,000 m, n = 12; BMI: 34.0 ± 0.8 kg/m <sup>2</sup> ) or normoxia (360 m, n = 11; BMI: 32.9 ± 0.8 kg/m <sup>2</sup> ). Participants performed six 5-minute walking trials at different speeds (PWS, 0.56, 0.83, 1.11, 1.39, and 1.67 m/s). The net energy cost, external mechanical work, and rated perceived exertion (RPE) were measured at these speeds. Body composition and blood samples were collected. PWS tended to be slower under hypoxia than normoxia (-6.7%; P = 0.092) during the training, and this difference reached significance the third week (-8.9%; P = 0.05). After training, PWS significantly increased (+ 8.2%; P ≤ 0.001), while RPE decreased (P = 0.005). Ankle range of motion (P = 0.03) and vertical displacement of the center of mass (P = 0.02) significantly increased in both groups. A walking training program under hypoxia at slower PWS than in normoxia elicited similar responses in metabolic risk factors, energetics, and mechanics of walking in individuals with obesity. Both programs increased PWS, decreased RPE, and induced gait-pattern adaptations, which protected against orthopedic injury in these individuals