title: Potassium kinetics and its relationship with ventilation during repeated bouts of exercise in women.
abstract: The purpose of this study was to determine the electrolyte concentration changes in arterial plasma from high-intensity repeated bouts of cycling exercise in well-trained females and to determine the relationships between arterial plasma lactate, potassium (K+), bicarbonate (HCO3(-)), and pH with minute ventilation. Fourteen female subjects (mean age = 27 +/- 4 years; mean height = 170 +/- 7 cm; mean weight = 62 +/- 7 kg; maximal oxygen uptake = 50 +/- 6 ml/kg/min) were recruited to perform 3 x 5 min bouts of exercise at 236 +/- 27 W with 10 min recovery between each set. Minute ventilation, arterial plasma lactate, potassium, calcium, chloride, and sodium ion concentrations were measured a minute 0, 1, 2, 3, 4, 5 of each set and midway through recovery (21 sampling points total per subject). The results showed that the strongest relationship was between arterial plasma K+ concentration and minute ventilation (r2 = 0.91), and, that arterial plasma lactate mirrored both arterial plasma HCO3(-) and pH. In conclusion, this study demonstrates that women exhibit similar electrolyte responses as reported elsewhere in men, and support the idea that K+ may partly contribute to controlling ventilation during high-intensity exercise and recovery.
authors.affiliation: Department of Anesthesia, McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, Room D10-144, H3G 1A4, Montreal, QC, Canada. gerald.zavorsky@mcgill.ca
authors.forename: Gerald S
authors.initials: GS
authors.lastname: Zavorsky
authors.forename: Jennifer
authors.initials: J
authors.lastname: Gow
authors.forename: Juan M
authors.initials: JM
authors.lastname: Murias
mesh_terms: D000328:Adult; D001639:Bicarbonates / Q000097:blood; D001642:Bicycling / Q000502:physiology*; D002118:Calcium / Q000097:blood; D002712:Chlorides / Q000097:blood; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019344:Lactic Acid / Q000097:blood; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D011188:Potassium / Q000097:blood*; D012123:Pulmonary Ventilation; D012964:Sodium / Q000097:blood; D013997:Time Factors
chemical_list: D001639:Bicarbonates; D002712:Chlorides; D019344:Lactic Acid; D012964:Sodium; D011188:Potassium; D002118:Calcium