Sport performance requires a multitude of contextual, movement-related cognitive demands for athletes [1], making cognitive processes essential to optimal sports performance [2]. At the same time, cognitive abilities developed by the sports practice may transfer to performance on everyday multitasking abilities [3-5]. This seems to be particularly relevant, especially during childhood, since children may benefit from higher cognitive abilities because of sport transfer skills to tasks of everyday living such as paying attention in class. Attention and concentration are two relevant aspects of the cognitive abilities during child development because they play a key role in the learning process [6], and in sports performances [2].

Regular participation in physical activity and sport leads to neurobiological adaptations that facilitate selected cognitive functions [7, 8]. Physical exercise arouses two types of neurophysiological changes: (a) a transient modulation of neural network involved in the cognitive task that underlies transitory behavioral and psychological changes; and (b) durable neurophysiological changes in brain structure that underlies stable behavioral and psychological changes [9, 10].

Acute exercise-induced modifications on cognitive performances are determined by the interactive effects between acute and chronic exercise [7]. Previous researchers reported that acute exercise produced beneficial effects on children’s and adolescents’ accuracy and speed of response [11], memory [12], attention and concentration capacity [13, 14], mental functioning [15], and executive functioning [16].

The impact of acute bouts of exercise on perceptual cognitive performance varies with the specific exercise and targeted perceptual cognitive process [17]. Mann et al. [18] asserted that the type of sport exercise or stimulus presentation affected the relationship between the athletes’ perceptual cognitive processing and their level of expertise. Pesce et al. [19] demonstrated that a 40-minute intervention, including team games and a circuit training benefited memory recall, also suggesting that task conditions promote mental engagement. Moreover, Voss et al. [20] reported that different sports experiences could influence mechanisms of brain plasticity due to the different mental demands of different sport types, thus moderating the sport-cognition relationship.

In closed skill sports, the environment is stable, more predictable, and self-paced by athletes who can plan their responses (e.g., running, swimming) [21]. In open skill sports, athletes react within continuously changing conditions, unpredictable and externally-paced environments (e.g., basketball, tennis, fencing) [22].

Previous studies reported that coordinative and game-based activities that characterized open skill sports, such as racquet sports or team sports, are beneficial for executive functions since they require high effortful cognitive processing continually changing task demands and, therefore, due to the necessity do adapt movements to these demands. In contrast, repetitive activities (e.g., running, swimming) require less such cognitive activities [23-25].

Although, in a recent meta-analysis, de Greeff et al. [26] reported no significant effects of acute cognitively engaging physical activity on cognitive functions, little is known about whether children’s mental functions can be modulated differentially through participation in different sport types (e.g., open skill and closed skill) [20] because of differences in required both cognitive and motor demands.

The last survey conducted by the National Institute of Statistics (Italy) revealed that the most popular sports among Italian youth were soccer, swimming, track and field (running, footing, and jogging) and racket sports [27]. However, football was almost exclusively practiced by boys, while swimming was mostly practiced by girls [27].

Therefore, the first aim of this study was to examine the attentional performance of children who practiced two different sport disciplines: open skill sport – racket and closed skill sport – running and to investigate the acute effects of these two specific training sessions on children’s immediate and delayed attentional performance. The second aim of the present study was to verify gender differences in attentional performance.

Attentional variable scores for girls and boys of open and closed skill sports are reported in (Table 1). No significant differences in age and anthropometric data between children of open and closed skill sports were revealed (p > 0.05). For each training session, differences in the baseline attentional scores were verified, revealing better attentional performances (higher TN, higher CP and lower E%; p < 0.01) in open vs closed skill sport. Moreover, no significant differences in the baseline attentional variable scores between boys and girls were revealed (p > 0.05).

Table 2 reports the ANOVA results on attentional variable scores: main effects of Time, Sport, Gender, and Time x Sport, Time x Gender, Time x Sport x Gender, Sport x Gender interactions. Children of open skill sport revealed better attentional performances than children of closed skill sport (p < 0.001). The ANOVA revealed differential effects of Sport on CP and E% change after experimental sessions. Specifically, the Bonferroni adjusted post-hoc analysis revealed that children of open skill sport significantly improved their CP from pre to 0’ post intervention (p = 0.01) and maintained this improved performance at 50’ post intervention (50’ post vs pre; p < 0.01). Children of closed skill sport did not change their CP from pre to 0’ post intervention and significantly decreased their performance at 50’ post intervention (50’ post vs pre; p = 0.001 and 50’ post vs 0’ post; p < 0.0001) Fig. (1A). Moreover, children of open skill sport significantly improved their E% from pre to 0’ post intervention (p = 0.01) and maintained this improvement at 50’ post intervention (50’ post vs pre; p < 0.001). Children of closed skill sport did not change their E% from pre to 0’ post intervention and significantly worsened their performance at 50’ post intervention (50’ post vs pre; p = 0.001 and 50’ post vs 0’ post; p < 0.0001) Fig. (1B).

Fig (1). Pre intervention, 0’ post intervention, and 50’ post intervention CP (concentration performance) (1A) and E% (percentage of errors) (1B) scores for open and closed skill sports.

Boys showed significantly higher TN values than girls only in closed skill sport (p = 0.023) Fig. (2). Finally, all girls of both open and closed skill sports significantly improved their CP from pre to 0’ post intervention (p = 0.04) Fig. (3).

Fig. (2). TN (total number of items processed) score in girls and boys of open and closed skill sports.

Fig. (3). Pre intervention, 0’ post intervention, and 50’ post intervention CP (concentration performance) score of girls and boys. * p < 0.05 vs pre (only for girls).

Open skill sports practice may advantage athletes with a greater improvement in the development of executive processes respect to closed skill sports practice [32]. In open skill sports, accurate timing, temporal estimations, temporal production, and spatial adjustments were required to provide improved cognitive performances [33]. In our study, children engaging in racket sport showed higher attentional performances in all attentional variables than their peers engaging in running. Voss et al. [20] argued that sports training leads to more efficient brain networks and brain plasticity, enhancing cognitive processing. Davis et al. [34] hypothesized that exercise-related cognitive benefits might be due to neural stimulation by the coordinative and cognitive complexity of the open-skill intervention, which enhances the efficiency of the brain. They also proposed the existence of a link between exercise and cognitive performance as a direct result of neural stimulation by movement [34]. The biological mechanisms due to exercise induce brain activity changes facilitating children’s cognitive functions. Racket sports, categorized as open skill sports, providing more competition, reaction to multiple different stimuli, varied scenarios/conditions and social interaction than running, positively affected children’s attentional performance. Our results agree with previous researches revealing that athletes from open skill sports performed better in cognitive tasks than those practicing closed skill sports [18, 20] and the practice of open skill sports was associated with the improvement of the executive functions [32]. The sensorimotor learning in sports plays a key role in linking training experiences with an enhancement of attentional performance [35]. The more cognitively demanding is the sports training, the greater are the cognitive effects that occur [35]. Therefore, training background in sports that require complex bodily movements and skill learning (e.g. tennis) could lead to better attentional performance than simpler and repetitive exercises (e.g. running).

The second aim of the present study was to investigate the acute effects of an open or a closed skill sport training session on children’s immediate and delayed attentional performance. Our study highlighted differences across sport types. Children of open skill sport significantly improved their attentional performance after the experimental session. Specifically, they improved their CP with a lower E% immediately after the experimental session and retained these effects until 50’ post. Conversely, children of closed skill sport did not change their concentration performance and accuracy (CP and E%) immediately after the experimental session but decreased their concentration performance and accuracy at 50’ post. In our study, children of racket sport completed a complex number of movements in relation to spatio-temporal dimensions (succession reversibility, simultaneity) with another player. The movements (integrating different stimuli, timing strategy, temporal accuracy, reaction time and coordination) resulted to be effective to induce an improvement of attentional performances.

Our results are in line with the previous findings by Budde et al. [36] who observed that 10 min of acute exercise with high coordinative and attentional requests produced higher benefits on 13–16-year-old adolescents’ attentional performance and concentration than aerobic exercise. These authors hypothesized the existence of a possible relation between concentration performance and coordinative exercise. Acute bouts of exercise of high complexity induced beneficial effects on attentional performance and concentration due to the activation of specific brain regions. Specifically, the activation of the prefrontal cortex during movement of high complexity seemed to be the possible mechanism responsible for this relationship between acute exercise and attention. The complex coordination exercises in racket sport required frontal-dependent cognitive processes enhancing prefrontal neural functioning. The mental switching process from internal to external, from narrow to broad during performance, could induce an improvement of attentional functions, such as visual perceptual speed and concentration performance. Previous research reported that children who are involved in the play and structured games that involved learning and group cooperation might adapt differently than children who are involved in individual physical activities [37]. Moreover, repetitive exercise did not rely on frontal circuitry to induce an improvement of attentional variables, explaining our results of the running group. The greater is the cognitive engagement of exercise, the stronger is the effect on attentional performance [38]. Our results are inconsistent with those of our two previous studies [13, 14], showing that coordinative exertion type led to a lower improvement of concentration performance over time than cognitive exertion and physical exertion types. The different context where the experimental sessions were conducted (sport club vs school setting) and participants’ age (8–11-year-old primary school students vs 8–13-year-old athletes) may be the reason for the disparate findings.

Finally, our results revealed gender differences in attentional performance. Previous studies showed higher performances in mathematical and spatial abilities and working memory in males respect to females who outperform males in fine motor skills, verbal fluency, perceptual speed, and accuracy [39, 40]. Even our study showed differences between girls and boys for processing speed (TN) only in closed skill sport. Specifically, boys showed higher values than girls. We hypothesized that running exercises proposed during the closed skill experimental session were more effective in boys to induce a quantitative improvement of the amount of work completed but not inaccuracy or concentration performance of the attentional test. Moreover, our study showed differences between girls’ and boys’ acute exercise response. Specifically, all girls of both open and closed skill sports benefitted from intervention improving their CP after experimental sessions. These results confirmed general findings supporting the idea that girls are more able in focusing their attention on a target, ignoring distractors, and executing a quick response [39]. Maturity could also play an important role in the gender differences in attentional performances. In particular, gender differences in cognitive abilities are more pronounced at puberty. During puberty, behavioral, hormonal, and neuroanatomical changes occur. Moreover, in this period there is the reorganization of the prefrontal cortex. It seems that pubertal onset is a critical transition for neural development and consequently for the cognitive functions [41, 42]. Boys mature later than girls [43], thus this delayed degree of development could differently affect cognitive performance and attentional responses to physical exercise. Therefore, in our study, it is not possible to exclude a potential influence of pubertal stage on boys’ and girls’ attentional response.

Finally, although most of the methods used to determine exercise intensity are based on heart rate (HR), in our study the exercise intensity of each training session was controlled using the OMNI scale [30]. A study reported significant relationship between heart rate and RPE using the OMNI (r = .69–.93) scale with children age 9 to 13 years involved in running activities [44]. However, this HR method was not a good indicator of the intensity of open skill sports characterized by certain circumstances such as motivational status, intermittent nature of training and cognitive demands [45]. A previous study showed that the RPE method was the better indicator of both physical and psychological stress of open skill sports, which also included technical and tactical objectives [45]. Moreover, the construct validity for the OMNI scale to control open skill exercise demands was previously demonstrated [45].

There are some limitations to the present study. First, it is difficult to generalize the change of attentional performances without the assessment of other neuropsychological functions beyond the performance on the d2 test of attention. The lack of a study of the relationship between sports experience and attentional capacity while controlling for physical fitness reduces the amount of causal evidence since fitness level may moderate the sport–cognition relationship. The association of attention data with racket sports and running could limit the generalizability of the study for all open and closed skill sports.

Further research is needed to investigate the effects of different open and closed skill sports on the function of attention maintenance in children with different levels of fitness.

In conclusion, our findings suggest the beneficial effect of racket (open) sport on children’s function of immediate and delayed attention when compared to running (closed). Therefore, we suggest including multilateral activities and varying type of exercises in closed skill sports training program, to favour not only physical and technical acquisition but also to improve cognitive functioning in these sports. Moreover, a multi-sport approach to children sports training, balancing open and closed skill activities, could be beneficial for the long-term athlete's physical and cognitive development. Further investigations are needed to verify if children’s attentional improvements due to sports practice may be transferred to performance on everyday abilities, including school learning.