TY - JOUR
T1 - Living high-training low increases hypoxic ventilatory response of well-trained endurance athletes
AU - Townsend, Nathan E.
AU - Gore, Christopher J.
AU - Hahn, Allan G.
AU - McKenna, Michael J.
AU - Aughey, Robert J.
AU - Clark, Sally A.
AU - Kinsman, Tahnee
AU - Hawley, John A.
AU - Chow, Chin Moi
PY - 2002/10
Y1 - 2002/10
N2 - This study determined whether "living high-training low" (LHTL)-simulated altitude exposure increased the hypoxic ventilatory response (HVR) in well-trained endurance athletes. Thirty-three cyclists/triathletes were divided into three groups: 20 consecutive nights of hypoxic exposure (LHTLc, n = 12), 20 nights of intermittent hypoxic exposure (four 5-night blocks of hypoxia, each interspersed with 2 nights of normoxia, LHTLi, n = 10), or control (Con, n = 11). LHTLc and LHTLi slept 8-10 h/day overnight in normobaric hypoxia (∼2,650 m); Con slept under ambient conditions (600 m). Resting, isocapnic HVR (ΔVE/ΔSpO2, where VE is minute ventilation and SpO2 is blood O2 saturation) was measured in normoxia before hypoxia (Pre), after 1, 3, 10, and 15 nights of exposure (N1, N3, N10, and N15, respectively), and 2 nights after the exposure night 20 (Post). Before each HVR test, end-tidal PCO2 (PETCO2) and VE were measured during room air breathing at rest. HVR (l·min-1·%-1 was higher (P < 0.05) in LHTLc than in Con at N1 (0.56 ± 0.32 vs. 0.28 ± 0.16), N3 (0.69 ± 0.30 vs. 0.36 ± 0.24), N10 (0.79 ± 0.36 vs. 0.34 ± 0.14), N15 (1.00 ± 0.38 vs. 0.36 ± 0.23), and Post (0.79 ± 0.37 vs. 0.36 ± 0.26). HVR at N15 was higher (P < 0.05) in LHTLi (0.67 ± 0.33) than in Con and in LHTLc than in LHTLi. PETCO2 was depressed in LHTLc and LHTLi compared with Con at all points after hypoxia (P < 0.05). No significant differences were observed for VE at any point. We conclude that LHTL increases HVR in endurance athletes in a time-dependent manner and decreases PETCO2 in normoxia, without change in VE. Thus endurance athletes sleeping in mild hypoxia may experience changes to the respiratory control system.
AB - This study determined whether "living high-training low" (LHTL)-simulated altitude exposure increased the hypoxic ventilatory response (HVR) in well-trained endurance athletes. Thirty-three cyclists/triathletes were divided into three groups: 20 consecutive nights of hypoxic exposure (LHTLc, n = 12), 20 nights of intermittent hypoxic exposure (four 5-night blocks of hypoxia, each interspersed with 2 nights of normoxia, LHTLi, n = 10), or control (Con, n = 11). LHTLc and LHTLi slept 8-10 h/day overnight in normobaric hypoxia (∼2,650 m); Con slept under ambient conditions (600 m). Resting, isocapnic HVR (ΔVE/ΔSpO2, where VE is minute ventilation and SpO2 is blood O2 saturation) was measured in normoxia before hypoxia (Pre), after 1, 3, 10, and 15 nights of exposure (N1, N3, N10, and N15, respectively), and 2 nights after the exposure night 20 (Post). Before each HVR test, end-tidal PCO2 (PETCO2) and VE were measured during room air breathing at rest. HVR (l·min-1·%-1 was higher (P < 0.05) in LHTLc than in Con at N1 (0.56 ± 0.32 vs. 0.28 ± 0.16), N3 (0.69 ± 0.30 vs. 0.36 ± 0.24), N10 (0.79 ± 0.36 vs. 0.34 ± 0.14), N15 (1.00 ± 0.38 vs. 0.36 ± 0.23), and Post (0.79 ± 0.37 vs. 0.36 ± 0.26). HVR at N15 was higher (P < 0.05) in LHTLi (0.67 ± 0.33) than in Con and in LHTLc than in LHTLi. PETCO2 was depressed in LHTLc and LHTLi compared with Con at all points after hypoxia (P < 0.05). No significant differences were observed for VE at any point. We conclude that LHTL increases HVR in endurance athletes in a time-dependent manner and decreases PETCO2 in normoxia, without change in VE. Thus endurance athletes sleeping in mild hypoxia may experience changes to the respiratory control system.
KW - Altitude training
KW - Chemoresponsiveness
KW - Cyclists
KW - Triathletes
KW - Ventilatory acclimatization
UR - http://www.scopus.com/inward/record.url?scp=0036784927&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00381.2002
DO - 10.1152/japplphysiol.00381.2002
M3 - Article
C2 - 12235052
AN - SCOPUS:0036784927
SN - 8750-7587
VL - 93
SP - 1498
EP - 1505
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 4
ER -