TY  -  JOUR
AU  -  Li, Caiyan
AU  -  Hurr, Chansol
AU  -  Lee, Seung-ro
AU  -  Hahn, Dongwoo
AU  -  Wang, Anjie
T1  -  The sympathetic response to hypoxic exercise: 
elevated but not prolonged
PY  -  2025
Y1  -  2025-04-01
DO  -  10.1728/4594.46014
JO  -  Medicina dello Sport
JA  -  Med Sport
VL  -  78
IS  -  2
SP  -  91
EP  -  97
PB  -  Il Pensiero Scientifico Editore
SN  -  1827-1863
Y2  -  2026/04/15
UR  -  http://dx.doi.org/10.1728/4594.46014
N2  -  Summary. Background. Hypoxic exercise has become an innovative approach to enhancing athletic performance and cardiovascular health. The response of sympathetic nerve activity (SNA) to hypoxia may offer unique benefits, although prolonged activation is associated with increased cardiovascular strain and delayed recovery. This study examined the effects of moderate-intensity aerobic exercise under normoxic (FiO2 = 20.9%) and hypoxic (FiO2 = 14%) conditions on SNA and physiological responses in healthy adults. Methods. This study employed a randomized crossover design. Eleven participants (eight males and three females) performed two 60-minute sessions of moderate-intensity aerobic exercise under normoxic and hypoxic conditions. SNA, mean arterial pressure (MAP), and heart rate (HR) were measured pre-exercise, immediately post-exercise, and during a 90-minute recovery period. Low-frequency (LF) and the LF/high -frequency (HF) ratio served as indicators of sympathetic activation. Results. After exercise, both LF and the LF/HF ratio were significantly higher in the hypoxic condition compared to the normoxic condition (LF: 0.532 ± 0.078 vs 0.461 ± 0.100 Hz, p = 0.021; LF/HF ratio: 0.918 ± 0.368 vs 1.172 ± 0.405, p = 0.018). Additionally, MAP was significantly lower under hypoxia than under normoxia (82.1 ± 7.7 vs 88.2 ± 6.2 mmHg, p = 0.008). No significant differences in these parameters were observed during the recovery period (all p > 0.05 from Post-30 to 90). Conclusions. These findings indicate that moderate-intensity hypoxic exercise transiently increases SNA and decreases MAP compared to normoxic exercise without prolonging recovery.
ER  -