Blood lactate disappearance dynamics in boys and men following exercise of similar and dissimilar peak-lactate concentrations.

Characteristically, children recover faster than adults from various types of exercise. The purpose of the present study was to explain the children's faster recovery, in part, by addressing lactate (La) removal and comparing La disappearance dynamics in the two age groups following exercise of both similar and dissimilar peak blood-lactate concentration values ([La]pk). The subjects were 14 prepubertal boys and 12 men of similar peak oxygen consumption, normalized for body mass. All subjects performed 30 s supra-maximal cycling (Wingate anaerobic test [WAnT]). [La]pk was 10.7 +/- 1.9 and 14.7 +/- 1.7 mmol x l(-1) for the boys and men, respectively (p < 0.001). The men were later retested in shortened versions of the WAnT so as to attain [La]pk values (10.5 +/- 0.7 mmol x l(-1)) comparable to those achieved by the boys. [La]pk lag time following the boys' standard WAnT was similar to that found in the men following the shortened WAnT (5.0 +/- 2.6 vs 5.7 +/- 1.3 min, respectively), but considerably shorter than that following the men's 30s-WAnT (7.6 +/- 2.1 min; p < 0.05). The La disappearance dynamics were closely matched between groups following the matched [La]pk WAnTs. [La] half-life was similar under all conditions (ca. 20 min). It is concluded that prepubertal boys are characterized by a lower [La]pk and a shorter time lag before reaching it, following 30-s supra-maximal cycling exercise. However, boys' La disappearance dynamics are not different from that of men.