The 800-m event, which is middle-distance running in athletics, is a type of racing based on aerobic and anaerobic characteristics [1]. Athletes usually reach running speeds near their maximum velocity in the first 200 m of the 800-m race [2]. Maintaining the optimal race speed in middle-distance races also depends on optimal neuromuscular and aerobic, anaerobic characteristics, running mechanics, and economy [3]. So physical performance characteristics such as muscle power and strength, speed, aerobic power, anaerobic power, and explosive power are essential factors determining success in the 800-m running events [4]. Therefore, coaches and athletes tend to deal with other training regimens, such as plyometrics, outside the traditional training model to improve 800-m race performance [5].

Plyometric training is considered to be one of the best methods to simultaneously improve physical performance characteristics based on neuromuscular activation, such as sprinting and jumping ability, explosive power, and muscle force [6]. During plyometric training, the neuromuscular system is overloaded, affecting the motor unit function, leg firing stiffness, muscle-tendon structure, and intramuscular coordination [7], [8]. This development potentially provides distance runners with a strategy to improve their running economy and neuromuscular function [9], [10]. Plyometric exercise has also provided an advantage in preventing lower extremity injuries, particularly in female athletes [11], [12]. Because of their larger Q angles, female athletes are more at risk of lower extremities, particularly knee injuries, than male athletes. In addition, young female athletes are more prone to lower extremity injuries than adults [13]. Studies have shown that plyometric training is a convenient method for improving physical fitness and reducing the risk of lower extremity injuries, particularly in young athletes [7].

Systematic and meta-analysis studies have shown on the effectiveness of plyometric training on the physical performance characteristics of athletes related to neuromuscular function, especially jumping, speed, and muscle strength. However, these review studies pointed out that most plyometric training research was related to male athletes. Additionally, studies on plyometric training in middle-distance runners are limited [14], [15], [16]. As regards, it was reported in a study that plyometric training had a significant effect on the improvement of 2.4 km endurance running time, sprint speed, drop jumping, and vertical jump abilities of both highly trained adult male and female middle-distance runners [1].

It was stated that middle-distance runners, especially young female athletes (age 12–18), have little experience with the effectiveness of plyometric training on physical fitness and reducing the risk of injury [16]. Although plyometric training is effective in improving the physical performance characteristics of athletes, its effectiveness on middle-distance runners is not yet apparent due to the limited number of studies. In addition, no analysis has yet been found on the effects of plyometric training on both the physical and running performance of young female middle-distance runners. Therefore, this study examined the effects of plyometric exercises, which were interspersed in two seasons of weekly traditional training programs, on the selected physical performance characteristics and race scores of 800-m young female runners.