Effect of combined plyometric and eccentric strength training on fascicle length, pennation angle and sprint performance in male sprinters

Background and Study Aim. Neuromuscular, biomechanical, and anatomical features interact in a complicated way to determine sprint performance. Characteristics of muscle architecture, such as fascicle length and pennation angle, are important structural predictors of an individual’s capacity to sprint due to their direct effects on force production, contraction velocity, and stretch-shortening cycle efficiency. The purpose of this study was to assess the effects of a 16-week combined plyometric and eccentric strength training program on fascicle length, pennation angle, and sprint performance in competitive male sprinters. Material and Methods. Thirty male sprinters aged 18–25 years from the Lakshmibai National Institute of Physical Education (Gwalior, Madhya Pradesh, India), were randomly assigned to an experimental group (n = 15) and a control group (n = 15). The experimental group underwent a sixteen-week combined plyometric and eccentric strength training intervention in addition to regular sprint training, while the control group continued routine sprint training. Muscle architectural variables of the dominant leg Vastus Lateralis were assessed using B-mode ultrasonography at Shaksam Diagnostics (Gwalior, Madhya Pradesh, India). Sprint performance was measured through a standardized 30-m sprint test. Results. Significant improvements were observed in fascicle length, pennation angle, and sprint performance in the experimental group compared to the control group (p < .001). ANCOVA analysis revealed statistically significant between-group differences in all dependent variables. Conclusions. Combined plyometric and eccentric strength training is an effective strategy for inducing favourable muscle architectural adaptations and improving sprint performance among competitive sprinters.