The skeletal muscle consists of two types of fibers - fast twitch and slow twitch. The slow-twitch fibers work efficiently for a long period of time while the fast-twitch fibers are responsible for the short and sudden burst of power necessary for sprinting or weightlifting. The ACTN3 gene is associated with the synthesis of alpha-actinin 3 protein present in the fast-twitch fibers (Type II) of skeletal muscle. The alpha-actinin 3 protein is found almost exclusively in the fast-twitch fibers. Specific alleles of this gene are known to either increase or decrease the extent of muscle power based on the synthesis of the alpha-actinin 3 protein. People with the C variant of the gene are associated with higher muscle power due to the presence of active alpha-actinin 3 protein while people with the T variant of the gene are associated with lower muscle power due to the presence of inactive alpha-actinin 3 protein. As a result, sprint or power athletes tend to have at least one copy of the C allele. Both the C and the T allele carriers have selective advantages in different environmental conditions.
[Limitation] Absence of active form of alpha-actinin 3 protein [Limitation] More likely to have lower muscle power [Advantage] Better suited for endurance-based activities
[Advantage] Presence of the active form of alpha-actinin 3 protein [Advantage] More likely to have moderate muscle power [Advantage] Better suited for sprinting
[Advantage] Presence of the active form of alpha-actinin 3 protein [Advantage] More likely to have higher muscle power [Advantage] Better suited for sprinting and power activities
For people with C variant (High Muscle Power), Greater power due to the presence of the active alpha-actinin 3 protein allows you to perform a variety of power-based activities like sprinting and weightlifting High-intensity workouts will yield better results Most elite sprinters and power athletes have at least one copy of this gene
For people with T variant (Low Muscle Power) Lower muscle power due to absence of the active alpha-actinin 3 protein Slow and efficient muscle performance will aid in endurance activities like long-distance running, playing tennis, basketball, and dancing. Low to mid-intensity workouts for longer durations will yield better results
Nan Yang, Daniel G. MacArthur, Jason P. Gulbin, Allan G. Hahn, Alan H. Beggs, Simon Easteal,and Kathryn North; “ACTN3 Genotype Is Associated with Human Elite Athletic Performance”; Am J Hum Genet. 2003
Seok-Ki Min, Seung-Taek Lim, and Chang-Sun Kim; “Association of ACTN3 polymorphisms with BMD, and physical fitness of elderly women”; J Phys Ther Sci. 2016 Oct
Find out which variation of the gene you carry and more at www.xcode.life
Nutrigenetics, fitness genetics, health genetics are all nascent but rapidly growing areas within human genetics. The information provided herein is based on preliminary scientific studies and it is to be read and understood in that context.