RESUMEN
The aim of the study was to determine which agility training program (low, moderate or high contextual interference) was more effective in first-grade primary school students to provide reliable information to physical education teachers for designing more effective agility programs. A total of 57 first-grade elementary school students participated in the present study. They were randomized into three groups to compare the effects of three different agility training programs based on contextual interference: low contextual interference (N = 19), moderate contextual interference (N = 19), and high contextual interference (N = 19). Contextual interference refers to the relative amount of interference created when integrating two or more tasks into a particular aspect of a training session. Significant improvements in agility were found in the low (p < 0.01, ES = 1.79) and moderate (p < 0.05, ES = 0.61) contextual interference groups after a 4-week training period. These improvements were higher in the low contextual interference group. The high contextual interference group showed no improvements (p > 0.05, ES = 0.28) after the intervention program. Our results suggested that the low contextual interference program is still more effective than the moderate contextual interference program in this group of primary school students.