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Effects of Varying Type of Exertion on Children’s Attention Capacity

GALLOTTA, MARIA CHIARA; GUIDETTI, LAURA; FRANCIOSI, EMANUELE; EMERENZIANI, GIAN PIETRO; BONAVOLONTÀ, VALERIO; BALDARI, CARLO

Medicine & Science in Sports & Exercise: March 2012 - Volume 44 - Issue 3 - p 550–555
doi: 10.1249/MSS.0b013e3182305552
Applied Sciences

Purpose The aim of this investigation was to examine the potential influence of varying types of exertion on immediate attentional performance on 138 primary school boys and girls.

Methods Subjects performed three different types of exertion [cognitive exertion (school curricular lesson), physical exertion (traditional physical education lesson), and mixed cognitive and physical exertion (coordinative physical education lesson)] at the same time of the school day for 3 wk. Before and immediately after each exertion session, subjects were administered the d2 Test of Attention.

Results Results showed that participants’ attentional performances were significantly affected by exertion type (cognitive exertion vs physical exertion vs mixed cognitive and physical exertion; P < 0.05), by intervention (before vs after; P < 0.05), and by exertion type × intervention interactions (P < 0.01).

Conclusions Our findings suggest that varying types of exertion have different beneficial influences on schoolchildren’s immediate cognitive performance.

Department of Health Sciences, University of Rome “Foro Italico,” Rome, ITALY

Address for correspondence: Carlo Baldari, Ph.D., University of Rome “Foro Italico,” Piazza Lauro De Bosis, 15, I-00135 Rome, Italy; E-mail: carlo.baldari@uniroma4.it.

Submitted for publication December 2010.

Accepted for publication July 2011.

It is well known that physical exercise could have positive effects on mental cognition (33). Many studies were conducted to investigate the short-term effects of acute, single bouts of exercise (3,6,20,22,35) on cognitive functions. Memory, speed of reaction, attention, and concentration are different and specific components of cognition (12,27,33). Attention and concentration are two aspects of cognitive function that assume particular relevance during development because they are key elements in the learning process (40). Research findings have shown that acute exercise of different duration (16,17,24), different intensities (3,6,21,35), and different types (5,9,27,29,37) can positively influence cognitive functions. Several researches suggest that bouts of physical exercise improve cognitive function in adults (3,35), but little is known about the possible differential effects of acute exercise on cognition during development (15,36), although recently, studies focusing on exercise in a school setting have been published (4–7,19). The effects of different types of acute exercise on cognitive functions, especially in attentional performance, are infrequently studied in children and adolescents. There is a lack of studies focusing on the qualitative aspects of PA (type of physical activity) in childhood, although the quality of motor experiences might contribute not only to physical and lifestyle development (1,23) but also to cognitive development (34). Physical education should be the primary context for such kind of research.

Many school teachers frequently claim that pupils who undergo prolonged periods of academic instruction often reduce their attention and concentration across school time (5,26). Therefore, physical education could represent an indispensable instrument to offer a quality experience of PA that can have a positive effect on these components of cognitive function, facilitating the learning process.

The aim of this study was to evaluate the potential influence of varying types of exertion on children’s attentional performances. Budde et al. (5) have already demonstrated that acute bouts of coordinative exercises improved attentional performance in adolescents. This improvement was probably due to the activation of some specific neuronal structures common to cognition and motor coordination. According to the theoretical background and partially to the design of this previous study, in the present one, we compared the level and quality of primary schoolchildren’s attention immediately before (PRE) and after (POST) three different types of school lessons. These school lessons were as follows: traditional physical education lesson, corresponding to physical exertion (PE); coordinative physical education lesson, corresponding to a mixed cognitive and physical exertion (CPE); and finally school curricular lesson, corresponding to cognitive exertion (CE), respectively. By proposing the same exercise intensity in both physical education lessons, according to the guidelines for school health PA programs to promote healthy behavior among children (10), we hypothesized that their different qualitative type might induce significant differences on immediate children’s attention. In fact, whereas the HR was controlled to impose the same exercise intensity, the main difference between the two physical education lessons was induced by the manipulation of qualitative aspects of a PA intervention concerning the level and variety of coordinative demands of the teaching contents (25). Specifically, PE was structured to focus on endurance exercises for cardiovascular health, whereas CPE was structured to focus on the high variability of motor coordination and skill learning demands.

The hypotheses to be tested were as follows: the level of attention will be higher at the end of physical education lessons than at the beginning because of the physiological arousal induced by acute bouts of exercise (3) and the level of attention will be lower at the end of CE lesson than at the beginning as frequently claimed by school teachers. We hypothesized that mental operations conducted in the process of learning in class cause a depletion of attentional capacity (29). And finally, the increase in attention will be higher after a CPE lesson than after a PE lesson as previously demonstrated for adolescents (5).

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METHODS

Participants

The sample was composed of 212 schoolchildren, ages 8--11 yr, who volunteered to participate in this study. They were selected from 13 classes of a primary school in Rome, Italy. These classes were as follows: four classes of grade 3, with a total of 79 children (8–9 yr); four classes of grade 4, with a total of 55 children (9–10 yr); and five classes of grade 5, with a total of 78 children (10–11 yr).

Children were eligible if they had no learning and academic difficulties, attention-deficit disorders, neurological and developmental disorders, dyslexia, or medical conditions that would affect study results or limit PA. The final sample consisted of 138 students. Reasons for missing data included not meeting the inclusion criteria or absence in at least one of the three experimental sessions.

The institutional review board of the University of Rome “Foro Italico” approved this investigation. Informed consent forms were obtained from both parents and children before study participation.

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Procedures

All children participated in three experimental sessions corresponding to the three different types of exertion (CE, PE, and CPE). Children completed the same attentional test before and after all three experimental sessions. The sequential order of these sessions for each class was counterbalanced and randomized according to a predetermined plan to control for the potential learning effects due to test repetition.

Experimental sessions occurred at the same time (in the morning) of the same school day for 3 wk. The school day was planned to have the same schedule every day during the experimental intervention.

The CE consisted of a 50-min academic class about humanistic subject matters (14).

The PE and CPE were equivalent in structure, total duration (50 min), and intensity. Both lessons started with 15 min of warm-up, followed with 30 min of continuous moderate to vigorous PA (MVPA), and ended with 5 min of cool down and stretching. The exercise intensity of both lessons was monitored by recording HR using an HR monitor (S610i; Polar Electro Oy, Kempele, Finland) to establish exertion in the MVPA range of an HR >139 bpm (38). To control HR trend, we defined preset HR target zones (MVPA) before exercise: an alarm sounded if the child’s HR was below the MVPA zone. This was to respect the continuous MVPA range and to avoid possible differences between lessons (Fig. 1). The CE and CPE differed only in type of PA that the children were engaged in.

FIGURE 1

FIGURE 1

The PE consisted of continuous aerobic circuit training (39) followed by a shuttle run exercise. This lesson was focused on the improvement of cardiovascular endurance by performing different types of gaits (e.g., fast walking, running, skipping) without any specific coordinative request (14). The PE provided changes in executive modalities and some variations of intensity (Fig. 1) but not rest periods.

The CPE consisted of the sport-unspecific use of basketballs in the context of mini games. The basketballs were used in unconventional ways with varying game rules (e.g., use of foot–eye coordination techniques with basketballs) (18,19). This lesson was geared toward the development of both motor control and perceptual motor adaptation abilities. These highly varied activities aimed to contribute to a multilateral development of coordinative abilities (30). This lesson was focused on the psychomotor competence and on the expertise in movement-based problem solving with functional use of a common tool (e.g., basketball), considering various tasks that involved decision-making motor tasks and manipulative ball handling skills (e.g., bouncing, throwing, receiving a ball, and their combination). Thus, accurate timing, temporal estimations, temporal production, and spatial adjustments were essential parts of the cognitive requirements to perform such kinds of activities (8). The CPE was aimed to develop both motor control abilities and perceptual motor adaptation abilities by combining demands on gross motor and manipulative control abilities and perceptual motor adaptation abilities (particularly kinesthetic differentiation and response orientation).

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Experimental measures

Immediately before and after each exertion session, children completed the d2 Test of Attention (2). It was developed to measure sustained attention and concentration under stress induced by a completion time. The d2 test is a paper-and-pencil letter cancellation test that consists of 14 different lines, each one composed of 47 randomly mixed letters (p, d), with one to four single and/or double quotation marks either over and/or under each letter. Children were required to mark, within 20 s for each line, only the letters “d” that have double quotation marks either above or below them. The test lasted 4.67 min. Each child’s score was determined by the total number of items processed (TN) within the d2 test, by the number of letters correctly marked minus errors of commission (CP), and by the percentage of errors (E%) made within all items processed. TN was a measure of processing speed and amount of work completed, CP was a measure of concentration performance, and E% was a measure of performance quality. A low error rate indicated high-quality performance. The range of the test reliability was between 0.95 and 0.98, and the validity coefficient was 0.47 (2).

The d2 test determines the capacity to focus on one stimulus/fact, while suppressing awareness to competing distractors (2). Processes of selective attention are also required for successful completion because not only the letter “d” is orthographically similar to the letter “p” but also there are many distractor letters “d” with more than two dashes (2). The performance on this test reflects visual perceptual speed and concentrative capacities.

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Statistical analysis

All results were expressed as mean ± SD. Individual scores (TN, E%, CP) were analyzed using a 3 × 2 × 2 mixed ANCOVA with exertion type (CE vs PE vs CPE) and intervention (POST vs PRE) as within factors, gender (male vs female) as between factor, and data from the first intervention (baseline) as covariate. Effect size was also calculated using Cohen’s definition of small, medium, and large effect size (as partial η 2 = 0.01, 0.06, 0.14). Significant interactions were further analyzed using planned pairwise comparisons. Within the gender factor, differences in the baseline attentional variable scores of males and females were verified using an unpaired comparison t-test. Moreover, for each attentional variable score evaluated after the intervention, we calculated the absolute variation (Δ) and the percentage of variation (Δ%) with respect to its preintervention value (postintervention value − preintervention value). ANOVA was then performed to examine the effect of exertion type (CE vs PE vs CPE) and gender (male vs female) on absolute variation in each attentional variable, followed by post hoc analysis (Bonferroni adjustment) to determine effects within the three exertion types.

Significant differences between PE and CPE exercise intensity were verified using planned pairwise comparison (t-test). Statistical significance was defined as P ≤ 0.05.

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RESULTS

Table 1 reports only significant results that are relevant for the present study: main effects of exertion type, intervention, and exertion type × intervention interactions. Differences in the baseline attentional variable scores of males and females were verified (P < 0.05), but no significant effects of gender were revealed. Children significantly improved their TN and CP individual values after intervention (P ≤ 0.01), whereas no significant differences were reported for the number of errors (E%) across intervention. Moreover, exertion type × intervention interactions indicate the likely presence of differential effects of the exertion type on both attentional variables development after intervention. Table 2 shows preintervention and postintervention individual scores and indicates that children improved their performances from before to after intervention to a lower degree when exerted in CPE condition compared with both CE and PE conditions. Improvement across intervention was analyzed using absolute variation (Δ) and percentage of variation (Δ%). ANOVA revealed a significant main effect of exertion type on ΔTN (F 2,282 = 11.64, P < 0.0001, η 2 = 0.07) and on ΔCP (F 2,282 = 7.26, P = 0.001, η 2 = 0.05), and on Δ%TN (F 2,282 = 12.07, P < 0.0001, η 2 = 0.07) and on Δ%CP (F 2,282 = 7.63, P = 0.001, η 2 = 0.05). These results revealed that CPE exertion type led to a lower improvement of TN and CP values (Figs. 2 and 3).

TABLE 1

TABLE 1

FIGURE 2

FIGURE 2

FIGURE 3

FIGURE 3

The HR verified that both physical education lessons (PE and CPE) had similar exercise intensity (146.56 ± 14.09 and 147.25 ± 15.50 bpm, respectively).

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DISCUSSION

This study investigated the potential influence of varying types of exertion on a pupil’s immediate attentional performance. In all three experimental sessions, TN and CP scores significantly changed at the end of the lessons. Specifically, schoolchildren showed higher working speed and concentration scores at the end of lesson rather than at the beginning (Table 2). Both values could be subject to learning effects; however, the internal test–retest reliability of the d2 Test of Attention was verified to be high (2). Because of the improvement in TN and CP over time in all three lessons, we cannot separate a general effect of exertion from a learning effect, which might interfere with the effect of varying types of exertion on attentional performance. However, the effect of practice was controlled and eliminated by using data from the first intervention (baseline) as covariate, and therefore, the statistical analysis showed a selective effect of the proposed lessons. Our findings revealed that the type of exertion had significantly different effects on the attentional variables measured. In particular, results revealed that CPE exertion type led to a lower improvement of TN and CP values compared with both CE and PE conditions (Figs. 2 and 3).

TABLE 2

TABLE 2

Our first hypothesis was supported because children showed a higher level of attention at the end of both physical education lessons than at the beginning. The facilitating effect of PE and CPE exertions on attentional performance could be justified by the physiological arousal induced by acute bouts of exercise (3) because they positively affect the brain’s neurochemistry (15), increase cerebral blood flow (15,35), excite the cerebellum and frontal cortex (5,13,31,32), improve brain function, and, finally, increase the steroid hormones’ concentration (6).

Our second hypothesis was that the level of attention and concentration could be lower at the end of the CE lesson than at the beginning. We hypothesized a reduction of attentional capacity because of the mental operations performed during the learning process. However, results did not support our hypothesis. Our results revealed that the level of attention was higher at the end of the CE lesson than at the beginning. As stated by Davies (11), a variety of stressors and/or motivational factors could influence the level of arousal, facilitating cognitive responses. Therefore, motivational factors, such as perceived self-efficacy, interest for the subject of the lesson, enjoyment, and teacher’s encouragement, could have positively affected attentional performance, then justifying this unexpected result. Previous studies (9,29) reported that the amelioration in concentration after a physical education class was not different from that observed after classroom activities. In fact, physical education could induce an increase of arousal level and then an improvement of attentional performance, whereas classroom activities could induce an increase in the attentional test because they could reflect the relative ease of transfer of the perceptual set from an academic class to a pen-and-paper test (29). Moreover, it has been shown that the level and quality of concentration and attention late in the school day were lower than those earlier in the day because of the effort required by the learning process (29). Therefore, the scheduling of school days should be organized considering the role of PA in the improvement of children’s attention. Physical education could be a valid help for children to concentrate on academic/cognitive tasks.

Finally, we hypothesized that the increase of attention will be higher after the CPE lesson than after the PE lesson. This difference could be induced by the different characteristics of PE lessons because the exercise intensity was the same. Specifically, we hypothesized that a mixed exertion (CPE) could induce a higher increase of attention capacity than a single type of exertion thanks to the combination of the positive effects on arousal increment induced by CE or PE alone. Moreover, Budde et al. (5) demonstrated that 10 min of coordinative exercises had a significantly positive effect on attentional performance in adolescents. These positive effects were hypothesized to be due to the activation of some specific neuronal structures (cerebellum and frontal cortex) common to cognition and motor coordination. In fact, some studies revealed the close relationship between coordinative abilities and cognitive performance because it seems that they depend on the same neuronal structures (5,28). Therefore, increasing the excitation of these structures by a CPE, we would expect a more pronounced increase in arousal level than would be reflected in a better attentional performance. This study’s hypothesis was not supported; in fact, the increase of attention was higher after both PE and CE lessons than after the CPE lesson. Referring to studies (36) that assume an inverted U-shaped function between arousal and performance, the lower improvement of cognitive performance after the CPE lesson could be due to an excessive stress/load induced by the mixed exertion. In fact, it was possible that the combination of the CE with the PE has moved the arousal increase toward the right side of the inverted U-shaped, with a consequent reduced increase of the cognitive performance. Moreover, the overall cognitive load due to the decision-making motor tasks and movement-based problem-solving contents of a 50-min CPE lesson was higher than that of 10-min coordinative exercises (5) and then resulting in the lower enhancement of attention and concentration performance after our CPE lesson.

Finally, our results revealed that reported baseline gender differences for TN and CP values did not interact with both intervention and exertion type, so that these differences disappeared with ANCOVA and in the absolute and percentage variation of both attentional variables.

The lack of statistically significant differences in E% after all three experimental sessions suggested that the enhancement in processing speed (TN) was not detrimental for the test’s accuracy. However, our results are inconsistent with the ones expressed by Budde et al. (5), which revealed a significant improvement in the performance quality across time. Specifically, these authors showed a significant decrease in the number of errors in adolescents after 10 min of coordinative exercise or after a normal sport lesson. Differences in intensity (122.13 ± 24.49 vs 146.90 ± 14.80 bpm, respectively) and duration of physical exercise proposed and differences in participants’ characteristics (e.g., age) could possibly account for the disparate findings.

Limitations of the study result from the lack of assessment of further neuropsychological functions beyond performance on the d2 test or the lack of a control group without any intervention that could limit the interpretation of the results.

In conclusion, our findings suggest that varying types of exertion have different beneficial influences on schoolchildren’s immediate cognitive performance. However, the present work does not allow us to verify the duration of the reported effects. Further research is needed to investigate the effects of different types of exertion on the function of attention maintenance in pupils.

This research was partially supported by funds from the Department of Health Sciences, University of Rome “Foro Italico,” Rome, Italy (M.C.G., main investigator).

The authors have no conflict of interest to declare.

The authors are very grateful to the Primary School G.B. Basile and to all children involved in the study, as without them this project could not be achieved. In addition, the authors thank Giorgio Pes and Serena Quartu for the achievement of the project.

The results of the present study do not constitute endorsement by the American College of Sports Medicine.

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Keywords:

PHYSICAL ACTIVITY; MVPA; COGNITIVE PERFORMANCE; SCHOOL CONTEXT

©2012The American College of Sports Medicine