Sport i Turystyka | 2026
Authors: Fentaw S.; Tadesse T.; Birhanu Z.
DOI: 10.16926/sit.2026.01.04
Journal: Sport i Turystyka
Year: 2026
Publisher: Stanislaw Podobinski Publishing House of the Jan Dlugosz University
Document Type: Article
Open Access: All Open Access; Gold Open Access; Green Open Access
Cited by: 0
High-intensity interval training (HIIT) under hypoxia has been demonstrated to increase sea-level athletes’ performance, but limited evidence exists regarding moderate-altitude runners. This study aimed to examine 8-week HIIT at low (~1,220 m) and moderate (~2,850 m) altitudes on physiological (maximal aerobic capacity (VO2max) and velocity associated with VO2max (vVO2max)) and functional (5,000 m running time (5kRT)) adaptations. Forty-two trained long-distance runners were randomly assigned to one of three groups: HIIT at 1,220 m (HIIT1220m, n=14), HIIT at 2,850 m (HIIT2850m, n=14) or control group at 2,850 m (CG2850m, n=14). While all participants maintained regular training at ~2,850 m, the HIIT groups completed two weekly sessions (4x4-minute work interval at 100% vVO2max, 3-minute recovery at 70% vVO2max). Both interventions had significant improvements over time (p < 0.05) in vVO2max, VO2max, and 5kRT, with greater gains in the HIIT1220m (+1.2%, +1%, –1.8%) than HIIT2850m (+0.6%, +0.8%, –1.4%), respectively. In addition, a strong correlation was observed in the HIIT2850m between changes in 5kRT and vVO2max (r=-0.64, p=0.013) and VO2max (r=0.74, p=0.002). In conclusion, HIIT at low altitudes induced greater functional improvements than it did at moderate altitudes. Thus, mod-erate-altitude long-distance athletes and coaches may benefit more when HIIT is strategically managed at lower altitudes. © 2026, Stanislaw Podobinski Publishing House of the Jan Dlugosz University. All rights reserved.
altitude residence; endurance training capacity; hypoxia; quality training; running success; sport performance