Know your genes: COL5A1-“The Flexibility Gene”


The COL5A1 gene is associated with the synthesis of type V collagen, a key constituent of ligaments and tendons. Specific alleles of this gene are known to either increase or decrease the risk of injury.


Does your 23andme, Ancestry DNA, FTDNA raw data have COL5A1 gene variant information?

23andMe (Use your 23andme raw data to know your COL5A1 Variant)
v1 23andmePresent
v2 23andmePresent
v3 23andmePresent
v4 23andmePresent
V5 23andme (current chip)Present
AncestryDNA  (Use your ancestry DNA raw data to know your COL5A1 Variant)
v1 ancestry DNAPresent
V2 ancestry DNA (current chip)Present
Family Tree DNA  (Use your FTDNA raw data to know your COL5A1 Variant)
OmniExpress microarray chipPresent

Association with Muscle Injury:

A study conducted on people with Achilles tendinopathy showed that those with the CC genotype of COL5A1 were associated with a lowered risk of developing Achilles tendinopathy compared to people with the T variant. Similar results were seen among people with anterior cruciate ligament injuries, again people with the CC genotype were found in lower numbers in a group of people with an ACL injury.

Association with Flexibility:

In terms of flexibility, people with the T variant of the gene are associated with a lower range of motion, implying that they could be less flexible. People with the TT genotype have tendons that are stiffer than those with the CC genotype. The stiff tendons and the lowered range of motion could be the reason behind the potential increase in the risk of injury among people with the TT genotype.  

Association with Endurance:

Stiffer Achilles tendons have an increased capacity to store and return energy thus providing an advantage in endurance running. This would mean that people with stiff Achilles tendons would require a lower amount of energy for every step, making such runners more efficient. This is what makes people with the T variant (less flexible) better suited for long-distance running events. Support for this theory comes from an ultra-marathon running study conducted in 2011. The study reported that people with the T variant had stiffer tendons but finished significantly faster than people with the C variant of the gene Col5A1.

Association with Likelihood of Fatigue:

In a study conducted on people with a self-reported history of exercise-associated muscle cramping, people with the C variant were shown to be over-represented among people with no history of exercise-associated muscle fatigue.





  • [Limitation] More likely to have stiff tendons and increased risk of injuries and tendinopathies.
  • [Limitation] Likely to have decreased range of motion (flexibility)
  • [Advantage] Better endurance
  • [Limitation] More likely to have a higher risk of muscle fatigue/ muscle cramping
  • Likely better at endurance running than the C variant
  • Increased risk for injuries – warm-ups and stretching before workouts are important to avoid injury. Recuperative therapies such as massages can help
  • Moderate range of motion (Flexibility)
  • Moderate risk of muscle fatigue
  • Greater flexibility due to an increased range of motion allows you to perform a variety of different exercises easily.
  • Lower risk of injury allows you to remain active and train often.

  1. Brown JC, Miller CJ, Posthumus M, Schwellnus MP, Collins M “The COL5A1 gene, ultra-marathon running performance, and range of motion.” Int J Sports Physiol Perform. 2011 Dec
  2. Posthumus M, September AV, O’Cuinneagain D, van der Merwe W, Schwellnus MP, Collins M “The COL5A1 gene is associated with increased risk of anterior cruciate ligament ruptures in female participants.” Am J Sports Med. 2009
  3. September AV1, Cook J, Handley CJ, van der Merwe L, Schwellnus MP, Collins M. “Variants within the COL5A1 gene are associated with Achilles tendinopathy in two .populations.” Br J Sports Med. 2009 May


“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.”