The elevation training mask induces modest hypoxaemia but does not affect heart rate variability during cycling in healthy adults

Hyun Chul Jung; Nan Hee Lee; Smith D John; Sukho Lee

doi:10.5114/biolsport.2019.79976

The elevation training mask induces modest hypoxaemia but does not affect heart rate variability during cycling in healthy adults

Biol Sport. 2019 Jun;36(2):105-112. doi: 10.5114/biolsport.2019.79976. Epub 2018 Nov 27.

Authors

Hyun Chul Jung¹, Nan Hee Lee², Smith D John³, Sukho Lee³

Affiliations

¹ Department of Kinesiology, College of Health Sciences, University of Louisiana at Monroe, 700 University Avenue Brown Hall 129, Monroe, LA 71209 USA.
² School of Biological Sciences, College of Sciences, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332 USA.
³ Department of Counseling, Health, and Kinesiology, College of Education and Human Development, Texas A&M University-San Antonio, One University Way, San Antonio, Texas, 78224 USA.

Abstract

This study examined the acute effects of the elevation training mask (ETM) on haemodynamics and heart rate variability (HRV) at rest, during cycling, and during recovery in healthy adults. Fifteen healthy male (N=9) and female (N=6) adults (27.0 ± 1.14 years) completed two trials with the mask (MASK) and without the mask (CON). The 40-minute cycling exercise protocol included 10-minute phases of (1) rest, (2) 50% of VO_2peak cycling, (3) 70% of VO_2peak cycling, and (4) recovery. Blood pressure and pulse oximetry saturation (S_PO₂) were measured at each phase. An Actiwave-Cardio ECG monitor (CamNtech, UK) was used to measure HRV variables including time and frequency domains. A greater response in systolic blood pressure (p=.035) was observed at rest while S_PO₂ (p=.033) was lower during high-intensity cycling (70% of VO_2peak) in the MASK trial. The HRV indices were not different between trials during cycling. However, heart rate (p=.047) was greater while inter-beat interval and sympathovagal balance (the ratio between low-frequency and high-frequency components; ln LF/HF, p=.01) were lower in the MASK than the CON trials during recovery. Wearing an ETM during high-intensity cycling (70% of VO_2peak) induces modest hypoxaemia. Although this device did not affect HRV changes during cycling, it seems to delay the cardiac-autonomic recovery from exercise. Healthy adults may be required to perform high-intensity exercise with an ETM to simulate a hypoxic environment, but future studies are needed to determine whether repeated exposure to this condition provides similar benefits as altitude training.

Keywords: Elevation training mask; Exercise; Haemodynamics; Heart rate variability.