TY - JOUR
T1 - Hypoxic ventilatory response is correlated with increased submaximal exercise ventilation after live high, train low
AU - Townsend, Nathan E.
AU - Gore, Christopher J.
AU - Hahn, Allan G.
AU - Aughey, Robert J.
AU - Clark, Sally A.
AU - Kinsman, Tahnee A.
AU - McKenna, Michael J.
AU - Hawley, John A.
AU - Chow, Chin Moi
PY - 2005/5
Y1 - 2005/5
N2 - This study tested the hypothesis that live high, train low (LHTL) would increase submaximal exercise ventilation (V̇E) in normoxia, and the increase would be related to enhanced hypoxic ventilatory response (HVR). Thirty-three cyclists/triathletes were divided into three groups: 20 consecutive nights of hypoxia (LHTLc, n =12), 20 nights of intermittent hypoxia (4x5-night 'blocks' of hypoxia interspersed by two nights of normoxia, LHTLi, n =10), or control (CON, n =11). LHTLc and LHTLi slept 8-10 h per night in normobaric hypoxia (2,650 m), and CON slept under ambient conditions (600 m). Resting, isocapnic HVR (ΔV̇E/Δblood oxygen saturation) was measured in normoxia before (PRE) and after 15 nights (N15) hypoxia. Submaximal cycle ergometry was conducted PRE and after 4, 10, and 19 nights of hypoxia (N4, N10, and N19 respectively). Mean submaximal exercise V̇E was increased (P<0.05) from PRE to N4 in LHTLc [74.4 (5.1) vs 80.0 (8.4) l min-1; mean (SD)] and in LHTLi [69.0 (7.5) vs 76.9 (7.3) l min-1] and remained elevated in both groups thereafter, with no changes observed in CON at any time. Prior to LHTL, submaximal V̇E was not correlated with HVR, but this relationship was significant at N4 (r=0.49, P=0.03) and N19 (r=0.77, P <0.0001). Additionally, the increases in submaximal V̇E and HVR from PRE to N15-N19 were correlated (r=0.51, P=0.02) for the pooled data of LHTLc and LHTLi. These results suggest that enhanced hypoxic chemosensitivity contributes to increased exercise V̇E in normoxia following LHTL.
AB - This study tested the hypothesis that live high, train low (LHTL) would increase submaximal exercise ventilation (V̇E) in normoxia, and the increase would be related to enhanced hypoxic ventilatory response (HVR). Thirty-three cyclists/triathletes were divided into three groups: 20 consecutive nights of hypoxia (LHTLc, n =12), 20 nights of intermittent hypoxia (4x5-night 'blocks' of hypoxia interspersed by two nights of normoxia, LHTLi, n =10), or control (CON, n =11). LHTLc and LHTLi slept 8-10 h per night in normobaric hypoxia (2,650 m), and CON slept under ambient conditions (600 m). Resting, isocapnic HVR (ΔV̇E/Δblood oxygen saturation) was measured in normoxia before (PRE) and after 15 nights (N15) hypoxia. Submaximal cycle ergometry was conducted PRE and after 4, 10, and 19 nights of hypoxia (N4, N10, and N19 respectively). Mean submaximal exercise V̇E was increased (P<0.05) from PRE to N4 in LHTLc [74.4 (5.1) vs 80.0 (8.4) l min-1; mean (SD)] and in LHTLi [69.0 (7.5) vs 76.9 (7.3) l min-1] and remained elevated in both groups thereafter, with no changes observed in CON at any time. Prior to LHTL, submaximal V̇E was not correlated with HVR, but this relationship was significant at N4 (r=0.49, P=0.03) and N19 (r=0.77, P <0.0001). Additionally, the increases in submaximal V̇E and HVR from PRE to N15-N19 were correlated (r=0.51, P=0.02) for the pooled data of LHTLc and LHTLi. These results suggest that enhanced hypoxic chemosensitivity contributes to increased exercise V̇E in normoxia following LHTL.
KW - Endurance athlete
KW - Peripheral chemosensitivity
KW - Simulated altitude
UR - http://www.scopus.com/inward/record.url?scp=23244462811&partnerID=8YFLogxK
U2 - 10.1007/s00421-004-1252-9
DO - 10.1007/s00421-004-1252-9
M3 - Article
C2 - 15609029
AN - SCOPUS:23244462811
SN - 1439-6319
VL - 94
SP - 207
EP - 215
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
IS - 1-2
ER -