Intermittent hypoxic exposure with or without exercise improved cardiopulmonary functions in people with cardiovascular risk factors

Abstract

This research aimed to explore the effects of intermittent hypoxic exposure (IH) with or without exercise on lung function, lipid profile, and a 6-min walk in people with three cardiovascular risk factors (hypertension stage I, hyperlipidemia, and obesity). Thirty participants were randomly allocated into 3 groups: a control group (CON, n=11) received no training, an intermittent hypoxic exposure during rest group (IHR, n=9), and an intermittent hypoxic training group (IHT, n=10) who combined IH with walking. Both IHR and IHT performed 8 sessions of 3-min of hypoxic breathing (14% O2) alternated with 3-min of normoxic breathing (21% O2) for 48-min per day, twice a week, for 6 consecutive weeks. All participants were measured before and after 6 weeks of theexperimental period. After training, IHR group significantly increased vital capacity (p=0.038) and forced vital capacity (p=0.025) compared to baseline. Similarly, compared to baseline, participants in the IHT group revealed significantly increased vital capacity (p=0.030), forced vital capacity (p=0.031), and forced expiratory volume in 1 second (p=0.042). Compared to CON, only IHT showed a significant increase in forced vital capacity of 8.6 ±4.5% (p=0.034) and forced expiratory volume in 1 second of 7.0 ± 3.9%, (p=0.033) after 6 weeks. Both the IHR and IHT participants demonstrated a significantly increased 6-min walk distance (p=0.048 and p=0.004, respectively) compared to CON. The study demonstrated that IH programs can improve lung function and cardiopulmonary fitness which indicates that IH with or without exercise improves some cardiopulmonary functions in at risk patients.