Can the Effects of Exercise Therapy on Achilles Tendinopathy Be Enhanced by Adding Nutritional Advice—A Randomized Controlled Pilot Study

Background: The progression of orthopedic diseases such as rheumatism and tendinopathies can be affected by metabolic conditions. Recent research suggests that changes in nutrition may affect symptom severity and recovery in orthopedic diseases. This study aims to explore whether the therapeutic efficacy of exercise therapy can be enhanced by adding nutritional advice in Achilles tendinopathy. Method: This 12-week randomized controlled pilot trial enrolled 16 adult patients (age 39.38 ± 9.46 years) suffering from chronic Achilles tendinopathy (≥3 months of symptoms, Victorian Institute of Sport Assessment—Achilles (VISA-A) scores below 80). Participants were randomly assigned to either the experimental group, receiving nutritional advice combined with home-based high-load tendon exercise training, or the control group, receiving exercise training alone. Outcomes included VISA-A scores, visual analog scale (VAS) pain assessments, body composition, and blood markers, analyzed through both intention-to-treat and per-protocol approaches. Results: Baseline characteristics showed no significant intergroup differences. From pre to post VISA-A scores increased from 58.06 ± 12.06 to 74.51 ± 17.81 points (p = 0.005) and VAS decreased from 3.19 ± 2.32 to 1.55 ± 1.66 points (p = 0.048) across all participants. Within-group analysis demonstrated a significant VISA-A improvement (63.13 ± 10.08 to 81.39 ± 13.13 points) (p = 0.013) in the experimental group only. The control group experienced a significant increase of 6.74 ± 12.26 mmHg in diastolic blood pressure (p = 0.046). Conclusions: The exercise intervention improved functional and pain outcomes in all participants, with better VISA-A outcomes in the experimental group. However, a clearly superior effect of the combined strategy compared with exercise alone could not be detected in this pilot study with a limited sample size.