Effect of hyperventilation and prior heavy exercise on O2 uptake and muscle deoxygenation kinetics during transitions to moderate exercise
In: European Journal of Applied Physiology, Jg. 108 (2009-11-28), S. 913-925
Online
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Zugriff:
The effect of hyperventilation-induced hypocapnic alkalosis (HYPO) and prior heavy-intensity exercise (HVY) on pulmonary O2 uptake $$ (\dot{V}{\text{O}}_{{ 2 {\text{p}}}}) $$ kinetics were examined in young adults (n = 7) during moderate-intensity exercise (MOD). Subjects completed leg cycling exercise during (1) normal breathing (CON, PETCO2 ~ 40 mmHg) and (2) controlled hyperventilation (HYPO, PETCO2 ~ 20 mmHg) throughout the protocol, with each condition repeated on four occasions. The protocol consisted of two MOD transitions (MOD1, MOD2) to 80% estimated lactate threshold with MOD2 preceded by HVY (Δ50%); each transition lasted 6 min and was preceded by 20 W cycling. $$ \dot{V}{\text{O}}_{{ 2 {\text{p}}}} $$ was measured breath-by-breath and concentration changes in oxy- and deoxy-hemoglobin/myoglobin (Δ[HHb]) of the vastus lateralis muscle were measured by near-infrared spectroscopy. Adjustment of $$ \dot{V}{\text{O}}_{{ 2 {\text{p}}}} $$ and Δ[HHb] were modeled using a mono-exponential equation by non-linear regression. During MOD1, the phase 2 time constant (τ) for $$ \dot{V}{\text{O}}_{{ 2 {\text{p}}}} \,(\tau \dot{V}{\text{O}}_{{ 2 {\text{p}}}} ) $$ was greater (P
Titel: |
Effect of hyperventilation and prior heavy exercise on O2 uptake and muscle deoxygenation kinetics during transitions to moderate exercise
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Autor/in / Beteiligte Person: | Heigenhauser, George J. F. ; Kowalchuk, John M. ; Lisa M.K. Chin ; Paterson, Donald H. |
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Zeitschrift: | European Journal of Applied Physiology, Jg. 108 (2009-11-28), S. 913-925 |
Veröffentlichung: | Springer Science and Business Media LLC, 2009 |
Medientyp: | unknown |
ISSN: | 1439-6327 (print) ; 1439-6319 (print) |
DOI: | 10.1007/s00421-009-1293-1 |
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