Related Experiment Videos
Plasma potassium and ventilation during incremental exercise in humans: modulation by sodium bicarbonate and
Summary
Exercise ventilation and plasma potassium changes are not significantly affected by plasma free fatty acids or increased plasma pH, even with altered nutrition or sodium bicarbonate intake. These physiological responses during exercise appear independent of these metabolic factors.
Area of Science:
- Exercise Physiology
- Metabolic Regulation
Background:
- Ventilation (VE) increases during exercise post-glycogen depletion, despite higher plasma pH (pHP).
- Reduced VE observed in McArdle's syndrome patients with improved substrate availability.
Purpose of the Study:
- To investigate the relationship between ventilation (VE), plasma potassium ([K+]P), and plasma pH (pHP) during exercise under varied nutritional conditions.
- To determine the impact of increased plasma free fatty acids ([FFA]P) and plasma pH on exercise ventilation and potassium levels.
Main Methods:
- Six endurance-trained men underwent incremental cyclo-ergometric exercise tests.
- Tests were performed after normal nutrition (N), a fatty meal (F), and a fatty meal with sodium bicarbonate (FSB).
- Measurements included VE, [K+]P, pHP, and [FFA]P.
Main Results:
- Plasma free fatty acid concentration ([FFA]P) increased significantly in F and FSB trials.
- Plasma pH (pHP) was significantly higher in FSB trials, remaining alkalotic even at maximal exercise.
- Exercise-induced changes in VE and [K+]P were similar across all trials and were not markedly affected by [FFA]P or pHP.
Conclusions:
- Exercise-induced ventilation and plasma potassium changes are largely independent of plasma free fatty acid levels and plasma pH.
- The findings suggest that these physiological responses during exercise are not significantly influenced by altered substrate availability or induced alkalosis.