Do tendons become thicker with exercise?

AI-generated illustration. Based on a photograph of Prof. Dr. Gürkan Özkoç; it does not depict an actual event or patient consultation.

Tendons transmit muscle-generated force to bones. It is incorrect to think tendons stop changing in adulthood. Tendon tissue can adapt over time to appropriate mechanical loading.

What does research show?

Systematic reviews and meta-analyses show that exercise can change tendon stiffness and mechanical tissue properties. Cross-sectional area, or thickness, may also increase, but this effect is generally smaller and more variable.

Results depend on the tendon studied, training load and duration, measurement method and individual. Tendon adaptation should not be expected to keep pace exactly with gains in muscle strength.

Is a thick tendon always healthy?

No. Thickening can also occur in painful tendon conditions. A thick appearance on ultrasound or MRI is therefore not, by itself, evidence of successful training; pain and function must also be considered.

Tendon adaptation progresses over weeks and months. Gradually increasing load and allowing recovery matter. Persistent focal pain or morning stiffness calls for a review of the programme. Stop exercising and seek medical assessment for a sudden snapping sensation and marked loss of function.

Sources

• Lazarczuk et al.: Tendon adaptations to loading (2022)
• Bohm et al.: Tendon adaptation (2015)

This article provides general information. Individual diagnosis and treatment require a clinical assessment.