El objetivo del presente estudio preliminar fue comparar la actividad muscular de los músculos tibial anterior, peroneo lateral largo, gastrocnemio medial y gastrocnemio lateral entre la carrera con y sin calzado, y la influencia de la fatiga. 7 participantes realizaron una carrera de fatiga de 20 minutos al 75% de su velocidad aeróbica máxima en cinta con 1% de pendiente. Se midió la actividad mioeléctrica de los músculos antes mencionados tanto antes como después de la prueba de fatiga en dos condiciones: con calzado y sin calzado. Los resultados mostraron una mayor actividad del tibial anterior durante la carrera en fatiga descalzo respecto a la carrera calzado y una mayor actividad del peroneo lateral largo durante la carrera sin fatiga descalzo. Por otra parte, también se encontró una menor actividad del gastrocnemio medial durante la carrera con zapatillas y en fatiga respecto a la carrera sin fatiga. ABSTRACT The aim of this preliminary study was to compare the influence of footwear and 13 the fatigue state on the muscle activity of the tibialis anterior, peroneus longus, gastrocnemius medialis and gastrocnemius lateralis. For this purpose, 7 participants ran a 20-min fatiguing run on a treadmill at 1% slope at 75% of their individual maximal aerobic speed. Muscle activation was measured twice during 30 seconds before and after the fatiguing run while running shod and barefoot. Before the fatiguing run, running barefoot led to a greater activation of the peroneus longus compared to running shod. When running fatigued, running barefoot also increased the activation of the tibialis anterior compared to running shod. Moreover, the fatigue state decreased the gastrocnemius medialis activity when running shod. The aim of this preliminary study was to compare the influence of footwear and the fatigue state on the muscle activity of the tibialis anterior, peroneus longus, gastrocnemius medialis and gastrocnemius lateralis. For this purpose, 7 participants ran a 20-min fatiguing run on a treadmill at 1% slope at 75% of their individual maximal aerobic speed. Muscle activation was measured twice during 30 seconds before and after the fatiguing run while running shod and barefoot. Before the fatiguing run, running barefoot led to a greater activation of the peroneus longus compared to running shod. When running fatigued, running barefoot also increased the activation of the tibialis anterior compared to running shod. Moreover, the fatigue state decreased the gastrocnemius medialis activity when running shod.