Revista Brasileira de Medicina do Esporte
Print version ISSN 1517-8692
CERQUEIRA, Lucenildo S; NOGUEIRA, Fernando S; CARVALHO, Joyce and POMPEU, Fernando A.M.S. Oxygen uptake kinetics and delta mechanical efficiency response of men and women at different exercise intensities. Rev Bras Med Esporte [online]. 2011, vol.17, n.4, pp. 274-278. ISSN 1517-8692. http://dx.doi.org/10.1590/S1517-86922011000400013.
ABSTRACT INTRODUCTION AND OBJECTIVE:Delta efficiency (DE) and oxygen uptake kinetics (K2) are influenced by muscle metabolic parameters and oxygen transport. The aim of this study was to determine the difference in DE and K2 in three effort intensities in both genders. METHODS: Fifty-six subjects (26 women) were submitted to a graded maximal exercise test (GXT) on cycle ergometer to determine the maximum oxygen uptake ( 2max ), maximal power output (Wmax), anaerobic threshold (AT) and respiratory compensation point (RCP). The AT and RCP were determined using the V-slope and E / 2 methods; the RCP using the relationship 2versus E both by two investigators. The DE and K2 have been considered as a slope between 2versus Watts and 2versus time (s), respectively, from the beginning of test until AT (S1), from AT to RCP (S2) and from RCP to 2max (S3), determined by linear regression analysis. RESULTS: Regarding DE, significant differences were observed between S1 versus S2 (p = 0.001), S1 versus S3 (p = 0.001) and S2 versus S3 (p = 0.006). There was no significant difference (p = 0.060) or interaction (p = 0.062) between men and women. For K2, significant differences were observed between S1 versus S3 (p = 0.001) and S2 versus S3 (p = 0.001) in both genders. Significant differences (p = 0.001) and interaction (p = 0.006) were observed between men and women, in the last parameter. CONCLUSIONS: DE decreases with increasing intensity of power output, but there are no differences when comparing men and women. On the other hand, women present faster K2than men
Keywords : ergospirometry; effort test; 2 e 2máx slow component.