Exertional Dyspnea During Exercise Training in Hypoxia in Overweight Women

Overweight is long-acting issue worldwide. Exercise in hypoxia is a novel method used nowadays to increase the benefits of exercise. Some studies demonstrated that hypoxic exposure can be detrimental for people with elevated body weight and can stimulate exertional dyspnea. Previous studies investigated the effect of overweight on exertional dyspnea in normoxia or investigated the benefits and limitation of training in hypoxia on athletes or clinical population. However, there are no studies looking into whether if training in hypoxia for healthy overweight women could stimulate exertional dyspnea or not. This study aimed to investigate whether training in hypoxia for overweight women can exacerbate exertional dyspnea or improve it. Eleven sedentary overweight females participated in this single-blind crossover design study (mean ± SD; BMI 31.2 ± 3 kg/m², age 24.8 ± 4.2 years, body mass 79.6 ± 7 kg). The participants completed two ramp test (VO_2max) sessions and two constant load interval session (3x10 session; 3x10 min walking at an intensity above GET; 3 min active rest below GET either in hypoxia (FiO₂ ≈ 14%) once in normoxia and once in normobaric hypoxia. The velocity of the treadmill was normalized for the given VO_2max in HYPO. Dyspnea-12, RPE, RPB, RPU and physiological variables were determined during the sessions. PANAS, negative feeling debriefing, and standard respiratory debriefing were conducted after the session. There was no significant difference between conditions in dypsnea-12, RPE, RPB, and RPU for both exercise intensity setting. Similarly, IRV, ERV, VT and VT/IC showed no significant main effect between conditions for the two-exercise intensity setting. Heart rate was similar across conditions for 3x10 session, and it was significantly higher during VO_2max. Based on that exercise in hypoxia is safe and beneficial for overweight women.