[Relationship of physical work capacity, blood pressure and other hypertension risk factors with the rate of erythrocyte Na/Li countertransport].

The relationship of physical working capacity (PWC), blood pressure and other arterial hypertension risk factors to the rate of red blood cell Na+/Li+ countertransport was examined in a representative sample comprising 60 individuals (22 males and 38 females) whose age was 35-54 years. Regression analyses demonstrated that there was no significant relationship between PWC and the rate of red blood cell Na+/Li+ countertransport, but a significant correlation was found between the rate of Na+/Li+ countertransport and "double product" (DP) as an indirect indicator of PWC and heart rate. Thus, there is a heart rate- and DP-mediated correlation between the rate of red blood cell Na+/Li+ countertransport and the level of PWC. The magnitude of a decrease in the rate of red blood cell Na+/Li+ countertransport depends inversely on the dynamics of heart rate in males and females and directly on the dynamics of DP in females. Hence, there is a direct relationship between the magnitude of a reduction in the rate of red blood cell Na+/Li+ countertransport and that of PWC increment during exercise.