Does Regular Exercise Change Your Achilles Tendon? New Twin Study Finally Has Answers

The calf muscle is connected to the heel bone by the largest tendon in the human body. We know that it works like a spring that stores and releases energy as we move our legs, but what we don't know is how it responds to exercise and training.

Is it possible that the characteristics of our Achilles tendons are set at birth by genetics, or can they adapt to long-term physical activity, thus protecting them from stress and overuse injury? A new study asked 40 pairs of identical twins about their exercise habits over the last few years.

The results of the surveys were compared against the qualities of the tissue with a handheld device. The researchers looked at the mechanical rigidity of the tendon to see if it was able to store more energy.

There is a lot of debate about the adaptation of the Achilles tendon in response to exercise activities.

Most published research is limited to elite athletes. There are no studies that control for genetic variation.

The team found that there was a lot of variation in the characteristics of the Achilles tendons, but not much difference in their strength.

In pairs where one twin was more active than the other, the tendons of the active individual were stiffened by an average of 28 percent. There is a chance that the Achilles tendon can be trained and adapted by regular, non-elite level exercise.

The findings match up with previous research done with elite-level runners that showed they had thicker and stronger Achilles tendons. It has been shown that straining tendons can cause cellular and molecular responses.

The researchers wrote that their study provided the first evidence that the individual's strength is determined by genetics.

The study shows that if you exercise regularly at a recreational level, you can cause the adaptation of the Achilles tendon.

The researchers found that exercises like basketball and running, where the feet completely leave the floor, have more impact on the Achilles tendon than exercises like swimming or cycling.

It seems likely that regular exercise activities with an aerial phase can increase the risk of an injury. The team concludes that individuals who participate in an exercise activity with an aerial phase should slowly increase their training intensity level to allow for the time needed to adapt to the high impact loading.

Scientists should be given more detail on why this is. Twins with different exercise schedules and different types of exercise would benefit from larger sample sizes.

The new study could help athletes tailor their training schedules, casual runners improve their technique, and doctors treat injuries to this important body part.

The new results offer new insights into the impact of genetic variation on individual Achilles tendon stiffness, which should be addressed more closely in future studies, according to the researchers.

The research has been published.