Is Tensiomyography-Derived Velocity Of Contraction A Sensitive Marker To Detect Acute Performance Changes In Elite Team-Sport Athletes?

Purpose: To examine the variations in the velocity of contraction (V-c) assessed using tensiomyography, vertical jumping ability, and sprinting speed induced by 4 different exercise protocols (ie, strength, sprint, plyometric, and technical training sessions) in 14 male national-team rugby players (age 21.8 [2.6] y, weight 83.6 [8.5] kg, and height 177.4 [6.7] cm). Methods: Physical tests were conducted immediately before and after 4 distinct workouts in the following order: tensiomyography in the rectus femoris and biceps femoris muscles, squat and countermovement jumps, and 30-m sprint velocity. To analyze the differences in the assessed variables before and after each training session, the differences based on magnitudes were calculated. Results: After strength and plyometric workouts, the players presented possible to almost certain impairments in sprint and jump performance and in the V-c of the rectus femoris (effect sizes 0.26-0.64). After the sprint-training session, possible to very likely decreases were observed in the squat jump. 30-m sprint, and V-c of the biceps femoris (effect sizes 0.21-0.44). By contrast, after the technical training, athletes demonstrated a possible increase in the squat jump and V-c in both muscles examined (effect sizes 0.13-0.20). Conclusions: The main finding of this research is that, for the vast majority of results, the direction of changes observed in V-c were the same as those observed in performance assessments. This suggests that V-c might be used as a sensitive marker of acute variations in speed and power performance of elite team-sport athletes.