T2-weighted MR imaging of thigh muscle response in male distance runners wearing advanced footwear technology.

BACKGROUND

Advanced footwear technology shoes (AFTs) combine highly resilient midsoles with embedded carbon-fiber plates and are known to alter knee joint kinetics and perceived stability. Whether these biomechanical and perceptual differences translate into altered muscle metabolic responses at the thigh in running remains unclear.

OBJECTIVE

This study aimed to clarify whether AFTs elicited greater exercise-induced transverse relaxation times (T2) shifts (an MR imaging index of metabolic responses in activated muscles) in quadriceps and hamstrings compared with traditional running shoes (TRADs) during overground running in competitive male distance runners.

METHODS

Twelve trained male distance runners completed two sessions (randomized crossover) of 10-min overground running at 3'20″/km (18 km·h⁻¹) in AFTs or TRADs, separated by at least 6 days. T2-weighted MR images of the right thigh were obtained immediately before and after each run. T2 values were obtained and calculated for rectus femoris, vastus lateralis, vastus medialis, vastus intermedius, sartorius, adductors, biceps femoris, semitendinosus, and semimembranosus.

RESULTS

No significant Shoe × Time interactions were observed for the quadriceps, hamstrings, or other measured thigh muscles. A main effect of Time was observed in the biceps femoris, semitendinosus, semimembranosus and adductors in both AFTs and TRADs conditions. Running speed, heart rate, and perceived exertion did not differ between shoe conditions.

CONCLUSION

These findings suggest that exercise-induced T2 shifts in the thigh were not influenced by the interaction between the carbon-fiber plate and the highly resilient midsole in AFTs.