Characteristic feature of oxygen cost at simulated laboratory triathlon test in trained triathletes

Background. The present study was carried out in order to investigate the r espiratory and circulatory features during a simulated laboratory triathlon test in trained triathletes, Methods. Experimental design: Sixteen male triathletes were divided into su perior (n=8) and slower triathletes (n=8) according to their race time, The se subjects performed both maximal exercise tests and a simulated laborator y triathlon test (ST), The latter test consisted of flume-pool swimming for 30 min, ergometer cycling for 75 min and treadmill running for: 45 min as a continuous task. The exercise intensity was 60% of VO(2)max during swimmi ng, cycling and running, respectively, Results, In slower triathletes, VO2, minute ventilation (VE), heart rate (H R) and temperature of external auditory canal were increased from an earlie r stage compared with those in superior athletes. The percent increase (Del ta) of VO2, VE and HR between een the 10(th) and last min of cycling and ru nning stages in superior triathletes were significantly smaller than those in slower athletes, The oxygen cost (oxygen uptake/running velocity) of run ning stage was significantly lower in superior triathletes (0.220+/-0.020 m l kg(-1) m(-1)) compared with slower athletes (0.264+/-0.014 ml kg(-1) m(-1 )), Conclusions. These results suggest that superior triathletes performed ST m ore economically than slower athletes and had excellent thermoregulatory ad aptation.