caa a22 4500 469054514 CHVBK 20180323132839.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF00868138 doi (NATIONALLICENCE)springer-10.1007/BF00868138 Plasma potassium and ventilation during incremental exercise in humans: modulation by sodium bicarbonate and substrate availability [Elektronische Daten] [M. Busse, J. Scholz, N. Maassen] Summary: It has recently been demonstrated that, compared to normal conditions, ventilation ( $$\dot V_E $$ ) was increased during exercise after glycogen depletion, in spite of a marked increase in plasma pH (pHP). It was further demonstrated that $$\dot V_E $$ in patients with McArdle's syndrome was reduced when substrate availability was improved. In the present experiments, six endurance trained men performed two successive cyclo-ergometric incremental exercise tests (tests A, B) after normal nutrition (N) and after a fatty meal in conjunction with a sodium bicarbonate (NaHCO3) solution (FSB) or without NaHCO3 (F), and the relationship between $$\dot V_E $$ , plasma potassium concentration ([K+]P), and pHP was checked. Plasma free fatty acid concentration ([FFA]P) was markedly increased in the F and FSB trials (P<0.001). In FSB pHP was significantly increased, compared to N and F (P<0.001). In all the B tests, pHP increased during moderate and intense exercise and in FSB, remained alkalotic even during maximal exercise intensity. In contrast, $$\dot V_E $$ and [K+]P changes were almost equal in all the trials and in tests A and B. It was found that exercise-induced changes of $$\dot V_E $$ and [K+]P in the present experiments were not markedly affected by [FFA]P or pHP values and that these changes also occurred independently of changes in pHP or plasma bicarbonate concentration. The often used glycogen depletion strategy may have slightly increased $$\dot V_E $$ but apparently did not overcompensate for a possible decrease in $$\dot V_E $$ due to increased pHP. The close relationship between $$\dot V_E $$ and [K+]P was not affected by acid-base or substrate changes; this would further confirm the hypothesis that K+ may act as a stimulus for exercise $$\dot V_E $$ . Springer-Verlag, 1992 Exercise nationallicence Ventilation nationallicence Acid-base status nationallicence Nutrition nationallicence Potassium nationallicence Busse M. Department of Sports and Exercise Physiology (4251), Centre of Physiology, Medizinische Hochschule Hannover, W-3000, Hannover, Germany aut Scholz J. Department of Sports and Exercise Physiology (4251), Centre of Physiology, Medizinische Hochschule Hannover, W-3000, Hannover, Germany aut Maassen N. Department of Sports and Exercise Physiology (4251), Centre of Physiology, Medizinische Hochschule Hannover, W-3000, Hannover, Germany aut European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/4(1992-07-01), 340-346 0301-5548 65:4<340 1992 65 421 https://doi.org/10.1007/BF00868138 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00868138 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Busse M. Department of Sports and Exercise Physiology (4251), Centre of Physiology, Medizinische Hochschule Hannover, W-3000, Hannover, Germany aut NATIONALLICENCE 700 1- Scholz J. Department of Sports and Exercise Physiology (4251), Centre of Physiology, Medizinische Hochschule Hannover, W-3000, Hannover, Germany aut NATIONALLICENCE 700 1- Maassen N. Department of Sports and Exercise Physiology (4251), Centre of Physiology, Medizinische Hochschule Hannover, W-3000, Hannover, Germany aut NATIONALLICENCE 773 0- European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/4(1992-07-01), 340-346 0301-5548 65:4<340 1992 65 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer