This study examined the influence of the <img border=0 width=32 height=32 id="_x0000_i1078" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2 kinetics on the running strategy adopted during a 10km running race in runners with different performance levels. Twenty-one runners (28.5 ± 5.3 years; 17.6 ± 7.3 cm; 66.3 ± 9.3 kg) performed 1) a test with increments of 1.2 km.h-1every 3 min until exhaustion; 2) one 6-min test of constant velocity at 9 km.h-1 for determination of <img border=0 width=32 height=32 id="_x0000_i1077" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2 kinetics and; 3) a 10 km time trial simulation. The subjects were divided into two groups, Moderated Performance (MP) and Low Perfomance (LP), based on the 10-km running performance. Mean velocity (MP= 16.9 ± 0.8 vs BP= 14.9 ± 1 km.h-1) on the 10km race was significantly different (p<0.05) between groups. There were no differences (p>0.05) between groups in any kinetics parameters analyzed. However, the <img border=0 width=32 height=32 id="_x0000_i1076" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2 increase amplitude (A1 parameter) was inversely correlated with mean velocity (r= -0.48, p < 0.05) and with the partial velocities on time trial (r between -0.44 and -0.48, p < 0.05), except for the last session (r=-0.19, p > 0.05). In conclusion, the correlation of A1 parameter with the partial velocities suggests an influence of running economy on the strategy adopted during the 10 km time trial.
athletic performance; pulmonary gas exchange; physical exertion
