Variations in this gene will alter the expression of MCT1 which allows the clearance of lactic acid. This determines the onset of fatigue when exercising. Your FitnessGenes result tells you whether you carry the fast version, slow version or both versions of the lactic acid clearing gene. This will determine how quickly lactic acid accumulates during exercise.
Also referred to as SLC16A1, this gene codes for the level of MCT1, a molecule involved in the transport of lactic acid across the muscle cell membrane (sarcolemma). The more MCT1 present, the quicker lactic acid is removed. Variations in this gene will alter the levels of MCT1, influencing the rate of lactic acid removal and onset of fatigue when exercising. This gene difference involves an A and T allele; producing three different genotypes: AA, AT and TT. The T allele has been shown to be linked to slower lactic acid processing due to lower MCT1 levels. This genotype difference is only noted in males and is more evident at high intensities (~80% of 15RM).