Altitude training masks (ATMs) are frequently used during exercise to enhance physiologic adaptations, yet few studies have examined the effects of ATMS when used during recovery periods.
PURPOSE: To examine the effects of ATMs used only during low-intensity recovery intervals in a high-intensity interval training (HIIT) program in healthy young adults.
METHODS: Participants engaged in 18 HIIT over a 6-week period using a treadmill. HIIT sessions were comprised of 6-8, 60-second high-intensity bouts at a relative work rate corresponding to 95% of participants’ maximal heart rates, alternating with 90-second low-intensity recovery bouts at a relative work rate corresponding to 20% VO2max. Participants were randomly assigned to an experimental group (EXP) which wore an ATM only during the low-intensity bouts or to a control group (CON) which did not use an ATM. Cardiopulmonary exercise tests (CPET) were performed before and after the HIIT.
RESULTS: 10 participants completed the study in the EXP group (6 females; 26±4.1 years; BMI: 24.2±1.6 kg/m2) and 10 in the CON group (7 females; 24.3±3.5 years; BMI: 22.8±2.1 kg/m2). Both groups experienced improvements in VO2max (EXP: 39.9±4.6 vs. 42.8±6.0 ml/kg/min, p=0.02; CON: 39.7±6.1 vs. 43.9±8.3 ml/kg/min, p=0.01; baseline vs. follow-up, mean±SD). The EXP group alone saw improvements after training in time to anaerobic threshold (169±31.2 vs. 213±56.2 sec, p=0.04), increased peak work rate during CPET (44±26.9 vs. 88+54.3 Watts, p=0.03), and increased minute ventilation during peak exercise (108±15.5 to 113.64±19.6 L/min, p=0.04). No other changes were observed in the CON group.
CONCLUSIONS: Using ATMs only during the low-intensity bouts of HIIT appears to have afforded participants with unique training adaptations not observed in standard HIIT. Conventional use of ATMs employs the masks during exertional portions of exercise training, not solely during recovery periods. These findings suggest that ATMs may serve as a valuable training adjunct even if used only during recovery periods in HIIT. Supported by: GWU SMHS Emerging Scholars Award 2016-2018