Changes in Plasma Potassium During Graded Aerobic Exercise and Two Hours of Recovery

Plasma potassium increases with exercise intensity. Subjects (n=8) were monitored for changes in plasma potassium while exercising at progressively increasing steady-state intensities and for two hours of recovery. Plasma potassium was significantly increased at 100% of VO2peak compared to 20% and 40% (p<0.01). Plasma potassium at 60 and 120 minutes of recovery from exercise was significantly higher than 6 minutes post exercise (p<0.015). These results support the supposition that high-intensity exercise may lead to hyperkalemia, and also indicates that increases in [K+] occur up to two hours after the cessation of exercise, a newly reported phenomenon. Although, high levels of plasma potassium are known to cause cardiac abnormalities and related events, exercise induced changes in normal healthy adults are not currently believed to have clinical implications.