The relationship between plasma potassium, muscle membrane excitability and force following quadriceps fatigue

To examine the simultaneous changes in plasma [K+], muscle excitability and force during fatigue, ten male adults (mean age = 22 ± 0.5 years) held an isometric contraction of their right quadriceps muscle at an intensity of 30% maximum voluntary contraction (MVC) for 3 min. Femoral venous and brachial arterial [K+] were determined from serial samples drawn before, during, and for 15 min following the 3-min contraction. Each blood sample was …