Over the past decade many studies have used plyometric training (PT) to adapt the stretch-shortening cycle (SSC) (7). To date no studies have identified whether certain age groups in young girls are more responsive and susceptible to SSC function adaptation following PT.
During childhood, several physical attributes occur naturally in both sexes (1). Although not outlined in the literature of child performance development, Lloyd et al. (4) suggests that ‘accelerated adaptations’ in SSC function also occurs at different stages of childhood, and that SSC function can be amplified following PT (5). However, the authors identified this in boys only and did not study if this is also true of girls. If girls do demonstrate age-dependent periods of natural SSC development, such findings would have implications for the training of girls, in relation to the correct timing of exposure of PT to coincide with periods of heighten sensitivity to adaptation (1).
In the examination of SSC function in children, leg stiffness and reactive strength index (RSI) has been used as a measure of true SSC function (7). Currently, few studies have investigated leg stiffness and RSI in girls (2, 3), and the ones that have arguably included limitations: leg stiffness and RSI were not explored during pre-pubescence; the impact of leg stiffness and RSI on jumping and linear sprint ability was not measured; menstruation was not considered; and the ability of PT to amplify natural SSC function was not included. Therefore, taking a multifactorial approach to this problem may have implications on the training of girls SSC ability and PT in future.
Currently, no studies have examined whether girls can increase SSC function from a single weekly session of PT in the same way boys can, or whether sprint-only training (ST) increases SSC performance more than traditional PT, as demonstrated by adult males. Such findings might influence how young girls are coached for athletic performance in future. Further, both methods are time efficient and are less likely to result in impairment of performance due to fatigue. Additionally, there has been no examination of effects of different PT frequencies and volume might have in the maximal voluntary contraction (MVC) strength of girls, or whether menstruation will have a negative impact on knee extensor strength and therefore, it is reasonable to suggest more research is necessary in this area.
Despite the growing number PT studies, it remains unclear as to the effects of PT on leg stiffness and RSI in young girls. Therefore, the aim of this project is to the evaluate the effects of age and maturity on the responsiveness to PT of young girls, to determine whether certain age groups are more susceptible to PT adaption than others, and whether frequency and modality significantly alters SSC performance.