# Body Height Trajectories in Pediatric Competitive Athletes from 46 Different Sport Types
## 1 Introduction  
The numerous positive effects of physical activity and sports engagement in children and adolescents are well known [1, 2]. However, sports activity might harbor some level of concern from several aspects including growth. Competitive sports frequently involve high energy expenditure and sometimes insufficient energy intake due to the specific sport type's demands. Parents frequently worry that their child's athletic activities might hinder her/his statural growth, as certain athletes might lack the ideal environmental factors required to fulfill their height potential [3]. During the previous decades, several authors examined pediatric growth trajectories during sport training. [PERSON] [4] determined that there was neither a difference in the growth rates of 86 male adolescents from several countries who were moderately active or trained in sports nor in 131 female gymnasts, swimmers, rowers and track athletes from several countries. Yet, in another study, the growth rates of 22 female gymnasts who trained 22 h per week were lower compared with 21 swimmers who trained eight hours per week on average [5]. The authors concluded that heavy gymnastics training was associated with hindered growth rates to such an extent that full adult height would not be reached. Gymnasts from both sexes were the focus of additional studies. In a cohort of 86 male elite artistic gymnasts, their final height was shortercompared to that predicted from mid-parental heights [6]. Conversely, in another study of young female gymnasts, swimmers and tennis players, no significant differences were found in final adult heights in 110 athletes for whom these data were available [7]. A review of this topic in elite female gymnasts summarized that there is attenuated growth during the years of training, with catch up during reduced training periods [8]. Ultimately, in a report by the committee of the International Gymnastics Federation, the members concluded that the height of artistic gymnasts was not compromised by intensive training [9].  
There are very few studies that focused on other sport types. In a study of 50 competitive male wrestlers aged 13-15 years, there was no significant difference in height when compared with sedentary controls [10]. In a study of 82 novice female dancers aged 8-11 years, no difference in growth was seen over 3 years when compared with controls [11]. A study of 36 male and female distance runners aged 8-15 years, who were followed up for 4-5 years, also found no negative effects on growth rates [12]. Collectively, it appears that while some studies identified growth delays in young athletes, mainly female gymnasts, others did not. The previous studies that examined growth trajectories of young athletes were of relatively small sample sizes and focused on only a few selected sports disciplines. Data from additional sport types are needed to further examine the effects of competitive sports training on growth in children.  
The aim of this study was to determine height changes in pediatric competitive athletes from 46 sports types, who were repeatedly measured during annual preparticipation examinations. We hypothesized that there might be a hinderance to statural growth during this period of competitive training in some sport types, hence trajectories in the most common disciplines were examined separately.