LAUSR

AbstractThis study aimed to determine the neuromuscular changes in muscle contractile properties and CMJ performance after a Long Distance (LD) triathlon, inquiring to what extent it is influenced by gender and the evaluated muscle, and to explore for response differences. Four elite (2 females and 2 males) and eighteen well-trained triathletes (3 females and 15 males) who competed in the 2019 LD Triathlon World Championship undergone, prior and post-race, a Countermovement Jump (CMJ) and a muscle contractile properties assessment in Vastus Lateralis (VL) and Biceps Femoris (BF) using Tensiomyography. A mixed ANOVA was carried out to detect triathletes' neuromuscular changes after the competition. A large decrease in jump height and flight time was found in CMJ (p = 0.001, ηp2= 0.767) with gender differences (η2p = 0.308). Contraction (Tc), delay (Td) and sustain times (Ts) also showed a large decrease (p = 0.001, η2p = 0.174-0.413). However, maximum radial muscle belly displacement was not altered by the competition, but did greatly increase radial displacement velocity (p = 0.031; η2p = 0.212). No gender differences were found in contractile properties. Correlation analysis between race performance and the jumping and Tensiomyography parameters only showed a moderate negative correlation with Tc of the BF in pre- and post-competition (r = -0.44; -0.43; p = 0.05). In conclusion, triathletes after a LD World Championship suffer a sharp drop in jump performance and variations in VL's and BF's contractile properties, showing decreases in Tc, Td and Ts without gender differences. The regular use of these parameters can allow monitoring the triathlete's neuromuscular fatigue and aid in the distribution of more efficient loads in their training cycles.