The performance of long-distance runners is predicted by the interaction between physical variables, and plyometric and endurance training can change the interaction between these variables. In this way, it becomes necessary to investigate these promoted adaptations and how their transfer to performance occurs.

The study aimed to verify the combined effect of plyometric and endurance training on performance variables in long-distance runners.

The sample consisted of 23 male runners between 18 and 50 years old, athletes of 10km races and divided into two experimental groups: combined training (CT; Plyometric + endurance training; n = 11) and isolated training (ET; endurance training only; n = 12). The volunteers were submitted to two moments of evaluation, performed before and after the experimental protocol, consisting of anthropometric evaluations, muscle power, running economy, biomechanical test, maximum progressive test, and 10-km performance. For the experimental protocol, the volunteers were divided into pairs into the ET or CT groups according to the result obtained in the 10-kilometer test performed before the start of training. At the end of the experimental protocol (8 weeks), the athletes were reassessed, and the tests used were the same as those used in the initial assessment.

In muscle power tests, a significant increase in jumps (CMJ and SJ) was reported at the end of training, regardless of the evaluated group. In the biomechanical variables, an increase in contact time with the ground and vertical oscillation was found, in addition to a decrease in stride frequency and leg stiffness at the end of the training protocol, in both analyzed groups. Regarding the physiological variables, an increase in running economy, respiratory compensation points and peak velocity on treadmill was found, but VO2max remained stable after the experimental protocol. Finally, the final performance in the 10km did not show a significant effect, but the race strategy (initial phase) and peak velocity increased in both groups.

CT (endurance + plyometrics) elicited similar changes in muscle power, biomechanical, physiological and performance variables, when compared to runners who performed ET.

Even with the lowest volume of running in the CT group, the effects were similar to the group that only performed ET, a relevant finding when considering that a high volume of running training can lead to injuries due to stress or repetition. Based on our findings, it is recommended to include neuromuscular training in weekly training routines, with the insertion of activities aimed at improving contact with the ground, technical efficiency and energy use of the muscle stretching-shortening cycle. It is also suggested that the neuromuscular training load is established according to the periodization and is frequently controlled from the optimal height of the vertical jump. Finally, plyometric activities should be included in specific periods of the training routine, in which the main objective is to improve muscular power.