Kinetics of plasma potassium concentrations during exhausting exercise in trained and untrained men
- 53 Downloads
The purpose of this study was to examine the time course of changes in plasma potassium concentration during high intensity exercise and recovery in trained and untrained men. The subjects performed two exercise protocols, an incremental test and a sprint, on a cycle ergometer. A polyethylene catheter was inserted into the antecubital vein to obtain blood samples for the analysis of plasma electrolyte concentrations and acid-base parameters, during and after exercise. During both tests, venous plasma sodium, potassium and chloride concentrations increased in all the subjects, although the largest relative increase was detected in potassium concentration - 35% and 31% over rest in the progressive test and 61% and 37.7% in the sprint test, for cyclists and controls, respectively. After exercise plasma potassium concentration decreased exponentially to below resting values. There was a linear correlation between the amount of potassium accumulated in plasma during exercise and the amount eliminated from plasma when the exercise ceased. We found that, although plasma potassium accumulation occurred in both forms of exercise in the trained and nontrained subjects, the time constant of potassium decrease following exercise was shorter in the trained subjects. Thus, the trained subjects exhibited a better capacity to recover to resting concentrations of plasma potassium. We propose that the extracellular potassium accumulation acts as a negative feedback signal for sarcolemma excitability depending on the muscle metabolic rate.
Key wordsPlasma potassium Exhaustion Exercise pH Lactate
Unable to display preview. Download preview PDF.
- Ballanyi K, Grate P (1988) Changes in intracellular ion activities induced by adrenaline in human and rat skeletal muscle. Pflügers Arch 411: 283–288Google Scholar
- Blake GJ, Paterson DJ (1992) Effect of noradrenaline on systolic blood pressure and mean aortic flow in the anaesthetized rabbit during hyperkaliaemia. J Physiol 446: 216PGoogle Scholar
- Brenner BM, Berliner RW (1973) The transport of potassium. In: Handbook of Physiology, section 8. Renal physiology. American Physiology Society, Washington, DCGoogle Scholar
- Clausen T (1986) Regulation of active Na+-K+ transport in skeletal muscle. Physiol Rev 66: 554–580Google Scholar
- Clausen T, Everts ME, Kjeldsen K (1987) Quantification of the maximum capacity for active sodium-potassium transport in rat skeletal muscle. J Physiol 338: 163–181Google Scholar
- Everts ME, Retterstøl K, Clausen T (1988) Effects of adrenaline on excitation-induced stimulation of the sodium-potasium pump in rat skeletal muscle. Acta Physiol Scand 143: 189–198Google Scholar
- Fosha-Dolezal SR, Avery TB, Wagner WC, Fedde MR (1988) Changes in serum potassium concentration with exercise in Hereford calves: effects of adrenalectomy. Comp Biochem Physiol 91: 135–139Google Scholar
- Kiens B, Saltin B, (1986) Endurance training of man decrease muscle potassium loss during exercise. Acta Physiol Scand 126:20AGoogle Scholar
- Sneyd JR, Linton RAF, Band DM (1992) Intravenous infusion of adrenaline during exercise in man. J Physiol 446: 210PGoogle Scholar
- Viru A (1985) Hormones in muscular activity, vol.II. Adaptative effects of hormones in exercise. CRC Press, Boca Raton, Fla.Google Scholar