The Difference in Muscle Quality and Torque Production Between Sprinters and Jumpers in NCAA Division I Track Athletes

Jumping and sprinting events place mechanical demand on the neuromuscular system, which may result in event-specific differences in muscle quality and strength. Purpose: This study investigated differences in muscle quality, measured by echo intensity (EI), and strength, measured by peak torque (PT), between NCAA Division I jumpers and sprinters. Methods: Twenty-three NCAA Division I jumpers and short sprinters (15 females, 8 males; mean±SD, age: 20±1.5 years, body mass 64.3±10.4 kg, height 172.9±9.0 cm) completed the assessment of EI for the rectus femoris (RF) and hamstrings using ultrasound and isometric maximal voluntary contraction to measure PT for knee extensor and flexor. Linear mixed models were used to investigate the different between jumpers and sprinters with a Tuckey post-hoc analysis. Data were presented as emmean±standard error. Results: EI in left hamstring for sprinter (85.3±3.1) was lower jumpers (74.8±2.7, p=0.019) while there were no differences in right hamstring and right and left RF (P>0.05). Jumper had greater right knee extensor (211±14 N·m) and flexor (100±9 N·m) compared to sprinters (extensor, 155±13 N·m, p=0.008; flexor, 72±8 N·m, p=0.033) while there were no differences in left extensor and flexor (p>0.05). Conclusion: The jumpers demonstrated greater right knee extensor and flexor PT while muscle quality was better in left hamstring for sprinters. This information can be used to structure their training regimen.