Comparative Analysis of Concentric Variables during unloaded and loaded Depth Jumps

Abstract: This study explores the influence of external loading on concentric performance variables during depth jumps, a widely used plyometric exercise to enhance explosive power. Ten male athletes (mean age 22 ± 1 years) performed depth jumps from a standardized 75 cm height under three conditions: unloaded, with 5% of body weight, and with 10% of body weight added via weighted vests. Performance measures included jump height, take-off force, impact force, maximum concentric power, average concentric speed, and peak speed, recorded using a tri-axial G-sensor. Results revealed significant differences across conditions, with the 5% load producing notable improvements in force production and neuromuscular activation without compromising movement efficiency. Although the 10% load further altered performance, excessive resistance tended to reduce jump height and efficiency. These findings highlight the importance of optimizing external load in plyometric training, suggesting that moderate resistance (around 5% body weight) enhances concentric output while maintaining effective technique. The study provides valuable insights for strength and conditioning professionals in refining training prescriptions to maximize explosive strength, and it underscores the need for future research on long-term adaptations to incremental loading strategies.