TY - JOUR
T1 - Four weeks of normobaric "live high-train low" do not alter muscular or systemic capacity for maintaining pH and K+ homeostasis during intense exercise
AU - Nordsborg, Nikolai B
AU - Siebenmann, C
AU - Jacobs, R A
AU - Rasmussen, P
AU - Diaz, V
AU - Robach, P
AU - Lundby, Carsten
N1 - CURIS 2012 5200 0067
PY - 2012/6/15
Y1 - 2012/6/15
N2 - It was investigated if athletes subjected to 4 wk of living in normobaric hypoxia (3,000 m; 16 h/day) while training at 800-1,300 m ["live high-train low" (LHTL)] increase muscular and systemic capacity for maintaining pH and K+ homeostasis as well as intense exercise performance. The design was double-blind and placebo controlled. Mean power during 30-s all-out cycling was similar before and immediately after LHTL (650 ± 31 vs. 628 ± 32 W; n = 10) and placebo exposure (658 ± 22 vs. 660 ± 23 W; n = 6). Supporting the performance data, arterial plasma pH, lactate, and K+ during submaximal and maximal exercise were also unaffected by the intervention in both groups. In addition, muscle buffer capacity (in mmol H+·kg dry wt -1·pH-1) was similar before and after in both the LHTL (140 ± 12 vs. 140 ± 16) and placebo group (145 ± 2 vs. 140 ± 3). The expression of sarcolemmal H+ transporters (Na+/H+ exchanger 1, monocarboxylate transporters 1 and 4), as well as expression of Na+-K+ pump subunits-α1, -α2, and -β1 was also similar before and after the intervention. In conclusion, muscular and systemic capacity for maintaining pH and K+ balance during exercise is similar before and after 4 wk of placebo-controlled normobaric LHTL. In accordance, 30-s all-out sprint ability was similar before and after LHTL.
AB - It was investigated if athletes subjected to 4 wk of living in normobaric hypoxia (3,000 m; 16 h/day) while training at 800-1,300 m ["live high-train low" (LHTL)] increase muscular and systemic capacity for maintaining pH and K+ homeostasis as well as intense exercise performance. The design was double-blind and placebo controlled. Mean power during 30-s all-out cycling was similar before and immediately after LHTL (650 ± 31 vs. 628 ± 32 W; n = 10) and placebo exposure (658 ± 22 vs. 660 ± 23 W; n = 6). Supporting the performance data, arterial plasma pH, lactate, and K+ during submaximal and maximal exercise were also unaffected by the intervention in both groups. In addition, muscle buffer capacity (in mmol H+·kg dry wt -1·pH-1) was similar before and after in both the LHTL (140 ± 12 vs. 140 ± 16) and placebo group (145 ± 2 vs. 140 ± 3). The expression of sarcolemmal H+ transporters (Na+/H+ exchanger 1, monocarboxylate transporters 1 and 4), as well as expression of Na+-K+ pump subunits-α1, -α2, and -β1 was also similar before and after the intervention. In conclusion, muscular and systemic capacity for maintaining pH and K+ balance during exercise is similar before and after 4 wk of placebo-controlled normobaric LHTL. In accordance, 30-s all-out sprint ability was similar before and after LHTL.
U2 - 10.1152/japplphysiol.01353.2011
DO - 10.1152/japplphysiol.01353.2011
M3 - Journal article
C2 - 22461443
SN - 8750-7587
VL - 112
SP - 2027
EP - 2036
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 12
ER -