Effect of Concurrent Training on Middle-Distance Running Performances in Trained Athletes

This study investigated the impact of concurrent training on middle-distance running performance using a quasi-experimental pre-test/post-test design. Thirty middle-distance runners (age 17.30±0.59years, height 1.71±0.04m, and weight 63.09±2.09kg) were selected via simple random sampling from a pool of eligible athletes to ensure a representative sample. Following this selection, participants were assigned to one of three groups: Endurance Training Group (ETG), Strength Training Group (STG), or Concurrent Training Group (CTG) based on their baseline 2-km running performance. The intervention lasted 12 weeks, with each group training three times per week. Performance was assessed through local muscular endurance tests (squats and push-ups), estimated VO2max using the field-based Cooper test, and a 2-km time trial. Results indicated that the STG achieved significantly greater enhancements in squats and push-ups compared to both the ETG and CTG. While the ETG outperformed the STG in VO2max and time trial performance, the CTG demonstrated significant improvements over the ETG across all variables: squats, push-ups, VO2max, and time trials. Furthermore, significant time-group interaction effects were observed for nearly all metrics (p < 0.05). While the results yielded exceptionally large effect sizes, these should be interpreted with caution, as the values may be inflated by the small sample size (n = 10 per group) and the low within-group variability characteristic of a highly homogeneous, trained athletic cohort. This study concludes that a 12-week concurrent training program effectively improves a broad range of performance variables, successfully integrating the adaptations typically associated with exclusive strength and endurance modalities in trained middle-distance runners.