Influence of the MCT1-T1470A polymorphism (rs1049434) on blood lactate accumulation during different circuit weight trainings in men and women

Objectives: To analyze the effect of the MCT1 T1470A polymorphism (rs1049434) on venous blood lactate levels in men and women, during three different circuit weight training protocols. Design: Cross-sectional laboratory study. Methods: 14 women and 15 men, all caucasian and moderately active, performed three circuit training sessions (Weight Machine Protocol, Free Weight Protocol and Combined Protocol) at 70% of the 15 repetition maximum and 70% of the heart rate reserve, in non-consecutive days. The sessions included three sets of a circuit of eight exercises. Venous lactate measurements were obtained after each set and during the recoveries between sets (i.e. in min 3, 5, 7 and 9). One-way analysis of covariance and one-way analysis of covariance with repeated measures were used to determine differences among genotypes (AA, TA and TT) in lactate levels. Results: In men, the AA group had higher lactate values than the TT group in all the measures (p <= 0.03) except for the average lactate during the Weight Machine Protocol, in which a borderline significant difference was found (p=0.07). We did not observe differences across genotypes in females. Conclusions: Our data suggest an influence of the MCT1 polymorphism on lactate transport across sarcolemma in males. Future studies on lactate transport and metabolism should take into account the gender-specific results. (C) 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.