
27/09/2025
What is Achilles Tendinopathy?
Achilles tendinopathy is a condition that affects the tendon at the back of your ankle, the thick cord that connects your calf muscles to your heel bone. When the tendon is repeatedly loaded, such as through running/jumping during a Hyrox, it can become painful, swollen, or stiff, especially during or after physical activity.
You might notice:
A dull ache around your heel or lower calf.
Stiffness in the morning or after resting.
Pain when running, jumping, or going up on your toes.
Pain in the tendon usually builds up overtime, but can be made worse by a previous acute traumatic event e.g., Achilles tear.
Why It Occurs in Hyrox
The unique format of Hyrox, repeated 1km runs mixed with functional stations, can be tough on the Achilles.
Here’s why:
Repetitive Running: The repeated bouts of running place continuous load on the Achilles, especially if your form breaks down as fatigue sets in.
Heavy, Explosive Movements: Exercises like sled pushes and burpee broad jumps accumulate stress on the calf muscles, which pull on the Achilles tendon.
Specifically, sled pushing puts the soleus muscle under extra load because of the positive shin angle utilised (i.e., knee over toe). The soleus is a strong muscle and is connected to the Achilles tendon. However, combining sled pushing with repeated running may push the muscle and tendon over the limit.
Surface & Footwear: Competing on hard surfaces or using footwear that doesn’t support your running gait can increase the strain.
Training Volume: A sudden increase in running or high-impact exercises without enough rest or recovery is a major risk factor.
If this sounds familiar, get in touch with the TFD Therapy team to book in your treatment.