CARDIORESPIRATORY RESPONSES AND CIRCULATING METABOLITE CONCENTRATIONSIN MALE AND FEMALE ADOLESCENTS DURING A SIMULATED DUATHLON

This study compared markers of the metabolic processes occurring in ma le and female adolescent triathletes from two age groups (over 15 year s of age [O15] and under 15 years of age [U15]) during a laboratory ba sed duathlon. Participants were tested on three separate occasions; tw o peak (V) over dot O-2 tests on a treadmill and cycle ergometer, and a third session involved a simulated duathlon (2 km run, 12 km ride an d 4 km run for the O15 groupo or 1 km run, 8 km ride and 2 km run for the U15). Data collection included performance speed, cardiorespirator y responses and blood borne markers of exercise metabolism. The perfor mance speeds selected by the two age groups did not differ. The mean r elative percentage of (V) over dot O-2 peak at which subjects particip ated were 79 +/- 3, 77 +/- 4%, for the O15 males and females, and 71 /- 5 and 82 +/- 2%, for the U15 males and females, respectively. While the plasma metabolites of ammonia [NH3] and lactate [La] were not dif ferent between age groups and sex (p>0.05) there were however, higher concentrations recorded during the cycling phase when compared with th e Funning phases (p<0.05). The respective mean concentrations for NH3 and La were 80.5 +/- 5.6 mu M, and 4.9 +/- 0.3 mu M for cycling, and 5 6.3 +/- 2.7 mu M, and 2.7 +/- 0.2 mu M for the combined running phases .