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Know Your Genes: MCT1 – “The Muscle Fatigue Gene”

Lactate Threshold
Muscle Injury
Endurance and Power

The MCT1 gene is associated with the synthesis of MCT1, a molecule that transports lactic acid across the muscle cell membrane. Specific alleles of this gene are known to either increase or decrease the risk for fatigue and muscle injury after intense exercises. People with the T variant of the gene are associated with lower transport of lactic acid due to lower levels of MCT1, implying that they could experience earlier fatigue onset on exercising.

Association with Running:

A study conducted on sprint/power athletes showed that those with the TT genotype of MCT1 were associated with power athletes when compared to people with the A variant. Conversely, in a study conducted on rowers, the AA genotype was associated with greater frequency among endurance athletes.

Association with Muscle Injury:

People with the AA genotype are at a higher risk of muscle injury while the T variant of the gene may have a protective effect due to lowered transport of lactic acid into muscles for oxidation.





  • [Limitation] Lower lactate threshold, hence early fatigue onset
  • [Advantage] More likely to have lower risk of muscle injury
  • [Advantage] Better sprint running performance
  • Higher risk of fatigue- Mild to moderate intensity exercises will aid in lowering risk of fatigue
  • Better sprint running performance
  • Lower risk of muscle injury- Strength training results in low lactate accumulation for people with T variant.
  • Increasing the intake of magnesium rich foods in the diet like kidney beans, navy beans and pinto beans lower accumulation of lactic acid.
  • Moderate risk of fatigue
  • Better at endurance activities, such as long distance running, playing tennis, basketball, dancing and aerobics.
  • Increased risk for muscle injuries- Carrying out mild to moderate intensity exercises will lower risk of injuries. Strength training should be carried out with lower weight and more repetitions
  • [Advantage] Higher lactate threshold, hence later fatigue onset
  • [Limitation] More likely to have higher risk of muscle injury
  • [Advantage] Better endurance running performance


  1. Sawczuk M, Banting LK, Cięszczyk P, Maciejewska-Karłowska A, Zarębska A, Leońska-Duniec A, Jastrzębski Z, Bishop DJ, Eynon N. “MCT1 A1470T: a novel polymorphism for sprint performance?”; J Sci Med Sport. 2015 Jan
  2. Myosotis Massidda, Nir Eynon, Valeria Bachis, Laura Corrias, Claudia Culigioni, Francesco Piras, Paolo Cugia, Marco Scorcu and Carla M. Calò; “Influence of the MCT1 rs1049434 on Indirect Muscle Disorders/Injuries in Elite Football Players”; Sports Medicine – 2015
  3. Fedotovskaya ON1, Mustafina LJ, Popov DV, Vinogradova OL, Ahmetov II.; “A common polymorphism of the MCT1 gene and athletic performance.”; Int J Sports Physiol Perform. 2014 Jan

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