In:
Journal of Applied Physiology, American Physiological Society, Vol. 99, No. 2 ( 2005-08), p. 499-504
Abstract:
Whether age-related differences in blood lactate concentrations (BLC) reflect specific BLC kinetics was analyzed in 15 prepubescent boys (age 12.0 ± 0.6 yr, height 1.54 ± 0.06 m, body mass 40.0 ± 5.2 kg), 12 adolescents (16.3 ± 0.7 yr, 1.83 ± 0.07 m, 68.2 ± 7.5 kg), and 12 adults (27.2 ± 4.5 yr, 1.83 ± 0.06 m, 81.6 ± 6.9 kg) by use of a biexponential four-parameter kinetics model under Wingate Anaerobic Test conditions. The model predicts the lactate generated in the extravasal compartment (A), invasion ( k 1 ), and evasion ( k 2 ) of lactate into and out of the blood compartment, the BLC maximum (BLC max ), and corresponding time (TBLC max ). BLC max and TBLC max were lower ( P 〈 0.05) in boys (BLC max 10.2 ± 1.3 mmol/l, TBLC max 4.1 ± 0.4 min) than in adolescents (12.7 ± 1.0 mmol/l, 5.5 ± 0.7 min) and adults (13.7 ± 1.4 mmol/l, 5.7 ± 1.1 min). No differences were found in A related to the muscle mass (A MM ) and k 1 between boys (A MM : 22.8 ± 2.7 mmol/l, k 1 : 0.865 ± 0.115 min −1 ), adolescents (22.7 ± 1.3 mmol/l, 0.692 ± 0.221 min −1 ), and adults (24.7 ± 2.8 mmol/l, 0.687 ± 0.287 min −1 ). The k 2 was higher ( P 〈 0.01) in boys (2.87 10 −2 ± 0.75 10 −2 min −1 ) than in adolescents (2.03 × 10 −2 ± 0.89 × 10 −2 min −1 ) and adults (1.99 × 10 −2 ± 0.93 × 10 −2 min −1 ). Age-related differences in the BLC kinetics are unlikely to reflect differences in muscular lactate or lactate invasion but partly faster elimination out of the blood compartment.
Type of Medium:
Online Resource
ISSN:
8750-7587
,
1522-1601
DOI:
10.1152/japplphysiol.00062.2005
Language:
English
Publisher:
American Physiological Society
Publication Date:
2005
detail.hit.zdb_id:
1404365-8
SSG:
12
SSG:
31
