ABSTRACT
During strenuous exercise in adults several of the cytokines and inflammatory cells increase, with increases in leukocytes and IL-6 preceding the other cells (Ostrowski et al., 1999). These changes in immune cells are proposed to be related to increases in the catecholamines (Steensberg et al., 2001; Ortega et al., 2005). Also, the exercise-induced increase in IL-6 is hypothesized to cause elevations of cortisol and cortisol causes the elevations of circulating leukocytes (Steensberg et al., 2003). Strenuous exercise has consistently increased growth hormone (hGH) in both adults (Zaldivar et al., 2006) and children (Eliakim et al., 2006). Further, the increase in hGHhas been linked to increases in neutrophils (Zaldivar et al., 2006). The exercise-induced increase of hGH appears to be related to the andrenergic response to exercise (Vettor et al., 1997; Eliakim et al., 2006). Thus, in adults there appear to be relationships between the exercise-induced inflammatory responses and the stress hormone responses (Kappell et al., 1991b; Gabriel et al., 1992; Pedersen et al., 1997). These relationships have not been examined systematically in youth; thus, the purpose of this study was to examine these relationships in youth.
