AIH: acute intermittent hypoxia; AV O2: arteriovenous oxygen difference; BBS: Berg balance scale; BDNF: brain-derived neurotrophic factor; DGI: dynamic gait index; EQ-5D: EuroQol 5 Dimension; FIM: functional independence measure; HIGT: high-intensity gait training; HIIT: high-intensity interval training; HR: heart rate; MICT: moderate-intensity continuous training; NIHSS: National Institutes of Health Stroke Scale; RCT: randomized control trial; TMT-B: Trail Making Test-B; VO2: oxygen consumption. Here, BDNF is linked to stroke disorder.