Physical activity of children ages 6-8: the beginning of school attendance.

Fromel, Karel ; Stelzer, Jiri ; Groffik, Dorota 等

Abstract. This study investigated the physical activity (PA) levels of 6- to 8-yearold children over a seven-day period. The participants consisted of 35 girls and 36 boys in kindergarten and 113 girls and 131 boys in 1st grade. Physical activity (PA) is defined as "any body movement produced by skeletal muscles resulting in energy expenditure" and measured in this study using a Caltrac accelerometer. In addition to the data produced by the accelerometer, a detailed activity log was kept for each participant. The results revealed no statistically significant difference in PA levels between kindergarten and 1st-grade participants, F(1, 311) = 1.16, p = .282. However, boys were more physically active than girls F(1, 311) = 66.10, p < .001, [[omega].sup.2] = .17, and the level of PA was higher on school days than on free days for both sexes, F(1, 311) = 20.45, p < .001, [[omega].sup.2] = .06. Finally, the data on the children's PA at school strongly supports the importance of physical education lessons (PE lessons) and recess periods in the daily school routine.

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Reliable research data clearly show both the increasing incidence of corpulence and obesity among adult populations of developed countries and the alarming spread of the problem to very young age groups. For example, data from a nationally representative sample of 2,630 British children showed overweight incidence levels ranging from 22% at age 6 to 31% at age 15. The levels of obesity ranged from 10% at age 6 to 17% at age 15 (Reilly & Dorosty, 1999). Similarly, the obesity rate among U.S. school-age children has tripled from approximately 5% to 15% in the past 20 years (Lemonick, 2005).

In the same way, the obesity rate among 52 countries in the European region is rising and excess body weight is the most commonly found childhood disorder. The World Health Organization's European Health Report for 2005 points out that corpulence among children in Western Europe rose from 10% in the early 1980s to around 20% by the end of the 1990s. In Southern Europe, one child in three is overweight. Likewise, an international obesity task force (European Association for the Study of Obesity, 2005) found the obesity rate among children in Poland, the target country for this study, to be increasing as well. From 1995 to 2003, obesity among Polish children ranging in age from 7 to 11 increased from 7% to 18%.

The causes of this growing epidemic are the well-known combination of improper diet and sedentary lifestyle. As Thompson (1998) made patently clear:

Humans are designed and constructed for one thing--movement. Yet our society does everything it can to prevent movement. Our children have access to every "labor-saving" device that exists. They are not being saved at all, however, but rather being exposed to potential overweight, illness, and physiological deterioration. (Thompson, 1998, p. 69-70)

Although a solution that reverses this trend is straightforward--a nutritional diet and regular physical activity--implementation presents a formidable challenge. Gaining widespread adoption of these diet and exercise practices requires changing individual perceptions and attitudes toward the benefits of a healthy lifestyle. As suggested by Bandura (1986), Dewey (1933), and Pajares (1992), attitudes and underlying belief systems are considered the best indicators of the decisions people will make throughout their lives. Stelzer, Ernest, Fenster, and Langford (2004) recommended that the extent to which a healthy lifestyle is emphasized by teachers, media, and family determines how children will view these benefits. The greater the importance attached to healthy lifestyle choices, the more likely it is that children will develop positive attitudes toward them.

The likelihood of changing attitudes and perceptions is much higher with young people, whose predilections are still in the formative stage, than with adults, whose habits tend to be more firmly entrenched. Research suggests, however, that a successful strategy aimed at children and adolescents requires diligent planning around the following three key elements:

Creativity. Schools must design and generate interest in activity programs that provide attractive alternatives to options that encourage such sedentary habits as television viewing and video-game play. Many researchers are convinced that overindulgence in these potentially harmful choices is an important causal factor in childhood and teenage obesity. Data from studies by Crespo et al. (2001); Crespo and Arbesman (2003); Dennison, Erb, and Jenkins (2002); Dietz and Gortmaker (1985); Gortmaker et al. (1996); and MacKenzie (2000) reveal a strong positive correlation between time spent watching television or playing video games and obesity. Childhood obesity, in turn, has important consequences for adult health. Available data show that the increased incidence of obesity among children and adolescents leads to an increase in adult obesity (Flegal et al., 2002; Katzmarzyk, 2002; World Health Organization, 2005).

Combined Effort. The challenging task of inspiring young people to adopt healthy lifestyle habits is believed by many experts too important to be the sole responsibility of schools. For example, Sidentop (1999) argues that although the attitude of young people toward physical activity can be modified, that modification cannot be accomplished through the efforts of any single counseling group. He recommends a comprehensive three-prong strategy, one that coordinates the efforts of family, school, and community, to achieve a significant degree of success. Likewise, Gill (1997) suggests that prevention programs aimed at childhood and adolescent obesity should begin in early childhood, continue through adolescence into adulthood, and involve the efforts of the individual, the family, the school, and the community. Such programs should allow supporting groups to integrate with and build on the classroom efforts of physical educators.

Reliable Data. The importance placed by experts on reducing sedentary behavior toward the prevention of obesity and related illnesses has produced practical physical-activity guidelines for young people (Malina, 1996; NASPE, 2003; Pate, Baranowski, Dowda, & Trost, 1996; Sallis et al., 1994; U.S. Department of Health and Human Services, 2000). These guidelines, although useful for establishing minimum standards for periodic activity, provide little help in developing fitness programs sufficiently attractive to young people to entice behavior changes. Sirard and Pate (2001) indicated that a first step with these types of initiatives is to require a body of reliable data that clearly delineates the nature and extent of the activity or inactivity in which children of all age ranges are engaged. Research efforts along these lines can provide useful insights into the association between physical activity and health, and the means for monitoring secular trends in behavior. Equally important, having this information allows physical educators to more effectively channel their creative energy into designing appealing alternatives to sedentary activities for young people.

Although there have been studies on the physical activity levels of young people, the emphasis has been on older childhood through adolescence. Some consider that the strongest need for research is for the very young age groups, yet there is a dearth of information about that age range (Pate, Pfeiffer, Trost, Ziegler, & Dowda, 2004). The absence of a concentrated research effort here is surprising, because younger age groups offer mentors the greatest opportunity for planting the seeds of positive attitude development. In this regard, Sirard and Pate (2001) argued that an assessment of young children's activity interests would help determine the type of programs that will work well in community-based settings.

Scarcity is not the only problem surrounding research in this area. Early studies on the physical activity levels of young people suffered procedural problems. Researchers often relied on self-reporting tools, and the error rate associated with such techniques has been estimated to be as high as 35% to 50% (Welk, 2002). More recently, researchers have used more reliable and valid scientific measurement devices; the most commonly used among these is the accelerometer-based activity monitor. This powerful tool provides real-time estimates of the frequency, intensity, and duration of free-living physical activity (Freedson & Miller, 2000).

The purpose of this study was to examine physical activity levels of 6- to 8-year-old children over a seven-day period. The sample consisted of 315 Polish kindergarten and 1st-grade schoolchildren (35 girls and 36 boys from the kindergarten class and 113 girls and 131 boys from the 1st-grade class). Physical activity levels were defined, monitored, and recorded as "any body movement produced by skeletal muscles that results in energy expenditure," and this variable was measured using a Caltrac accelerometer. The research sought to determine whether significant differences in activity levels exist between 1) kindergarten children (6-7 years of age) and 1st-grade children (7-8 years of age), 2) boys and girls, 3) weekday and weekend activity, and 4) physical education classes and school recess periods.

Method

Participants

Three kindergartens and three elementary schools from the Katowice region in Poland participated in this research. The schools were selected with the criteria that 1) the local area included kindergarten programs and a nearby elementary school, and 2) the schools were from cities of different sizes. Children in the kindergarten programs did not receive any formal physical education (PE) lessons during the week. Roughly 30 minutes a day was scheduled for dancing, gymnastics, or some other health-related physical activity. At each elementary school, children in 1st grade received one 20-minute and three 10-minute recess periods throughout the day. In addition, they participated in three PE lessons a week, taught by a licensed general education teacher, rather than by a PE specialist.

Parents of all children were informed of the nature of the research, the project goals, and the contribution their cooperation would make to the children and the school. Written parental approval for participation in the research project was required, and parents were also asked to monitor and record the daily activity data for their children. Three parents declined participation in the study and nine parents failed to maintain data monitoring and recording to the completion date. The partial results for these children were not included in the analysis. Following completion of the study, parents received their child's individual results, and the participating schools were provided with aggregated data for that institution.

Measurements

Physical activity levels were determined using Caltrac accelerometers that provide an estimation of the number of kilocalories (kcal--often referred to as calories expended) that a person uses over a period of time. This device measures active energy expenditure (AEE--kcal-[kg.sup.-1].[day.sup.-1]) and total energy expenditure (TEE--kcal). Each child wore the Caltrac accelerometer in a covered, belted waist attachment positioned over the left hip. The attachment and positioning are consistent with that used in previous studies (Ekelund et al., 2001; Nilsson, Ekelund, Yngve, & Sjostrom, 2002). With the exception of periods of sleep, swimming, or personal hygiene, the accelerometer was worn the entire day for seven consecutive days.

Parents recorded physical activity data from the Caltrac accelerometer following morning hygiene and in the evening prior to bedtime. Parents were instructed to log data as closely as possible to the same time each day during the seven-day monitoring period. In addition to logging data from the Caltrac accelerometer, detailed information on physical activity that lasted more than 10 continuous minutes was recorded by parents or teachers. The record sheets for recording data were a modification of those used in the Sports, Play and Active Recreation for Kids (SPARK) project (Sallis et al., 1994). Children also recorded their arrival times at school and home as well as the times of the beginning and end of each lesson.

Design and Procedure

The study was part of a long-term, semi-longitudinal project. Data for the kindergarten sample were gathered in the fall of 2005 and in the fall of 2006 for 1st-graders. The collection of data for this study followed the general agreed-upon recommendations that objective, reliable measures of activity level and energy expenditure can only be obtained by:

* Continuous, daily monitoring of at least three to seven days (Loucaides, Chedzoy, & Bennett, 2003)

* Monitoring during both weekdays and weekends (Rowlands, Eston, & Ingledew, 1999)

* Monitoring activity during both structured physical education lessons as well as recess periods while at school and during free time when not at school (Gavarry, Giacomoni, Bernard, Seymat, & Falgairette, 2003; Mota, Santos, Guerra, Ribeirao, & Duarte, 2003).

The total amount of data collected for the participants represented 315 weeks or 2,205 days worth of data.

Physical activity data were analyzed and evaluated using a combination of descriptive statistics, bivariate correlation analysis, and Analysis of Variance (ANOVA) results. Two 2 x 2 x 2 (Gender x Class x Day) ANOVAs (one for energy expenditure and one for physical activity) were run with the following independent variable levels: gender (girls, boys), class (children from kindergarten, children from the 1st grade), and day (school day, free day). All statistics were calculated by the STATISTICA 6 software package.

Results

The Analysis of Variance test indicated no statistical significant difference ([F.sub.(1,311)] = 1.16, p = .282) between the active energy expenditure (AEE) levels (Table 2) of children in kindergarten (girls M = 8.80 kcal x [kg.sup.-1] x [day.sup.-1]; boys M = 12.15 kcal x [kg.sup.-1] x [day.sup.-1]) and children in 1st grade (girls 8.63 kcal x [kg.sup.-1] x [day.sup.-1]; boys 13.47 kcal x [kg.sup.-1] x [day.sup.-1]). However, the boys in both kindergarten and 1st grade were physically more active (AEE levels) than girls in those grades ([F.sub.(1, 311)] = 66.10,p < .001, [[omega].sup.2] = .17). No significant differences were found between the interaction effects of the Gender x Class variables [F.sub.(1, 311)] = 2.00, p = .158 or the interaction effects of Gender x Class x Day [F.sub.(1, 311)] = 1.21, p = .271. When looking at "Number of Minutes Per Day" of exercise (Table 2 - Total Recorded PA), although there was no statistical significant difference ([F.sub.(3, 311)] = 6.69, p = .083) between kindergarten children (girls 128.01 min/day; boys 118.49 min/day) and 1st-grade children (girls 109.05 min/day; boys 109.29 min/day), girls in kindergarten exercised for an average of 10 minutes more than boys in kindergarten and 20 minutes more than boys or girls in 1st grade.

Girls and boys in kindergarten and 1st grade reached a higher level of PA (AEE levels) on school days than on the weekend [F.sub.(1, 311)] = 20.45, p < .001, [[omega].sup.2] = .06. A statistical significant difference between school days and the weekend and between boys and girls was found only in 1st grade (p = .021), with the lowest average levels of AEE for girls on the weekend. This represents an average 24% reduction from their AEE levels on school days compared to the average 7% reduction for boys.

Figure 1 shows the average caloric expenditure between boys and girls during their lessons, PE lessons, a single recess period, and all recess periods combined. The children at school expended more calories during their recess times (an average of 194.84 kcal each day) than they expended during their scheduled PE lesson (144.74 kcal; taught three times a week by the general educator). Whereas the girls expended more energy during lessons, the greatest difference was the boys exerting almost 15% more energy than the girls during all the recesses combined.

Figures 2 and 3 indicate grade differences in the number of minutes engaged in a variety of activities for boys and girls. Although girls were engaged in PA for more minutes per day than the boys in kindergarten, boys exerted almost 50% more energy than girls (Table 2). A comparison of the minutes of activity in Figures 2 and 3 indicate that girls spent more time in sports games, outdoor PA, aerobics-dance, home PA, and fitness; boys, however, spent more time walking, playing games with PA, and swimming. The greatest disparity was between kindergarten girls (201 min a week) and boys (158 min a week) in how much time was spent engaged in sports games.

In 1st grade, girls and boys are engaged in physical activity for the same amount of time (boys = 109 min a week and girls = 109 min a week), but boys expended 56% more energy than girls (Table 2). Figure 2 indicates that the girls decreased their time spent in the top four activities (walking, sports games, outdoor PA, and aerobics-dance) between kindergarten and 1st grade.

In contrast, boys increased (although not statistically significant) their AEE between kindergarten and 1st grade (Table 2), but also decreased their time in sports games, outdoor PA, and aerobics-dance. They did, however, increase their walking and home PA and tripled their time swimming (one of the most energy-depleting activities). Finally, the graphs underscore the predominance of walking as an activity. Girls in both grades walked a total of 280 min/week and 241 min/week, respectively (Figure 2), and boys in both grades walked a total of 298 min/week and a total of 302 min/week, respectively (Figure 3).

Discussion

Grade Comparisons

The use of scientific tools, such as the accelerometer and pedometer, has allowed researchers to amass a repository of reliable physical-activity measurements on children in a wide range of age groups. Although there is a relative shortage of measurement data on very young children, previous studies clearly show an inverse relationship in which activity levels decrease with an increase in age (Lee, 2002; Strauss, Rodzilsky, Burack, & Colin, 2001), and excessive weight and obesity tend to track from childhood into adulthood (Guo, Wu, Chumlea, & Reche, 2002). Trost et al. (2002) found that this decline can began as early as the 1st- to 3rd-grade age ranges.

Somewhat contrary to Trost's findings, the data from this study show no statistically significant differences between the activity levels of the younger kindergarten boys and girls (6-7 years of age) and the older 1st-grade genders (7-8 years of age). Even though no statistical difference emerged, there was a consistent trend in the data from year to year. As Table 2 shows, girls consistently exerted less energy for AEE, AEESD, AEEFD, and had less Total Recorded PA in 1st grade than in kindergarten. Thus, it might be that it is during the kindergarten to 1st-grade years that we start to see a decline in the number of minutes that girls participate in physical activity. Of particular note, even in kindergarten, boys exerted an average of 38% more energy a day than girls, with a 64% difference between boys and girls on the weekend (Table 2). As there was considerably more teacher-led PA in kindergarten (a daily average of 39.34 minutes) than in 1st grade (a daily average of 27.03 minutes), this might help mediate the gender differences (only a 30% increase over girls during school time).

The Total Recorded PA levels for girls (128.01 and 109 min/day) and boys (109 min/day) shown on Table 2 are considerably higher than the 60 min/day minimum recommended by Biddle, Sallis, and Cavill (1998), the Food and Nutrition Board of the National Academies of Sciences (2002), the National Association for Sport and Physical Education (NASPE, 2003), and the U.S. Department of Health and Human Services (2005). Figures 1, 2, and 3 indicate that the activity most responsible for the above-standard PA levels for our participants was walking, followed by sports games. Herein the lies paradox: This finding supports the view that these activities are the logical building blocks for creative programs designed to entice children to substitute a healthy lifestyle for such sedentary activities as television watching and video-game playing. However, as the data indicate, although girls engage in a greater amount of exercise than boys in kindergarten (time), boys expend a greater degree of energy (intensity). As the data suggest, it isn't really a question of more or less walking, but rather of the intensity of walking, if walking is to be used as an activity that leads to a healthier lifestyle. Similarly, it isn't whether young children engage in group games, but whether the teachers/instructors engage young children in cooperative small groups that emphasize participation and consider the "size, confidence, and skill levels of the children" (NASPE, 2003, p. 16).

Gender Comparisons

As measured by both AEE and Total Recorded PA values for kindergarten and 1st grade (Table 2), boys reached higher levels of physical activity than girls, both on school days and free days. More surprising, however, is the number of girls in kindergarten and 1st grade who did not reach the recommended AEE levels. Eight and one-half percent of kindergarten girls and 26.3% of the 1st grade girls did not reach the AEE levels of 6 kcal.[kg-.sup.1].[day-.sup.1] and 9 kcal.[kg-.sup.1].[day-.sup.1], respectively, recommended by Fromel, Novosad, and Svozil (1999).

Our data on male and female activity levels is consistent with that of numerous studies, such as those by Eaton and Ennis (1986); Metcalf, Voss, and Wilkin (2002); Molnar and Livingstone (2000); Mota, Santos, Guerra, Ribeirao, & Duarte (2002); Pate et al. (2002); and Thomas and French (1985). An often espoused view identifies environmental factors (socio-cultural and socio-economic) as the primary influence on physical-activity behavior during the prepuberty period, and the interaction of biological and environment factors following puberty (Thomas & Thomas, 1988). Trost et al. (2002) found environmental factors accounting for some of the differences in physical activity in a sample of 365 fifth-graders, and Thomas and Thomas (1988) found that pre-puberty differences in motor performance, physical activity, and health-related physical fitness are most likely attributed to societal expectations and treatment of girls and women. Based on their findings, Thomas and Thomas (1988, p. 227) warned that establishing lower fitness standards for female children often results in a "self-fulfilling prophecy: girls participate, perform, practice, compete and behave exactly as society expects."

A seminal study of over 9,500 four- to eight-year-olds in England (Williams, Wetton, & Moon, 1987) found that from the age of 5 (kindergarten in the United States), when boys and girls were asked to match pictures to the question "What do you do that makes you healthy?", boys were most likely to choose exercise. Girls chose food as the major theme until the age of 7, when the primary answer became exercise. The authors' list of possible reasons focused heavily on media and family influences. It therefore seems highly plausible that children as young as kindergarten are differentially influenced by their observations, and that these are already affecting their physical activity behavior.

Weekday and Weekend Comparisons

The decline in physical activity levels on weekends implies the strong presence of family and socio-cultural influences contributing to sedentary behavior. More research is needed to glean a better understanding of the environmental and cultural factors giving rise to the decline in weekend activity levels as well as the increasing trend of obesity rates among Polish children. However, two points are clear: First, the development of favorable attitudes and perceptions toward physical activity must begin with young children, or else the obesity problem compounds with age. For example, Magarey, Daniels, Boulton, and Cockington (2003) suggests that corpulence carries over into adulthood for 70% of overweight children. Second, the challenge of inspiring children to adopt healthy lifestyle habits extends beyond the school setting, and the physical educator should be the catalyst for designing and organizing creative extracurricular and community programs that meet the needs of young people.

Recess and Physical Education

The findings from this study support the widely held view that recess and teacher-led physical education classes are key components of any physical activity initiative for young schoolchildren. Policies from professional organizations and researchers (e.g., Council on Physical Education for Children, 2001; Jarret et al., 2001; Pellegrini, Davis-Huberty, & Jones, 1995; Ridgers, Stratton, Fairclough, & Twisk, 2007) recommend the school as the logical starting point for promoting healthy lifestyle habits and recess and physical education as valuable opportunities to engage in moderate to vigorous physical activity. Recess is also considered an occasion for developing social skills and an aid to staying alert and attentive in class (Jarrett et al., 2001).

Consistent with the findings of Ridgers et al. (2007), our data show higher levels of activity during recess periods than during physical education class. Participants expended 194.84 kcal in combined daily recess periods versus 144.74 kcal in one physical education class. Verstraete, Cardon, De Clercq, & De Bourdeaudhuij (2006) and Ridgers et al. (2007) also found that introducing environmental and structural interventions into the recess period increased physical activity levels. Verstraete et al. tested the use of game equipment on activity levels during recess and found that its use significantly increased activity levels of the intervention group over the control group. Ridgers et al. measured physical activity levels at selected playgrounds before and after those sites were newly equipped and redesigned. Although the impact of the new equipment and design increased the absolute levels of both moderate and vigorous physical activity of the sample, the increases were not statistically significant.

The decline in overall physical activity levels of our participants on the weekend also underscores the importance of teacher-led physical education classes. For young children, these classes serve a dual purpose: providing the health benefits associated with physical activity as well as providing the opportunity to experience different forms of exercise, develop complex motor skills, and integrate movement with learning.

Our data showing the increase in activity levels associated with teacher-led PE classes are consistent with those of other studies. For example, Datar and Sturm (2004) found that having one additional hour of PE in 1st grade over kindergarten significantly reduced the body mass index (BMI) of female children. Likewise, Sallis, McKenzie, Kolody, Faucette, and Hovell (1997) examined the difference in physical activity levels of 4th- and 5th-grade girls in health-related PE classes taught by a trained PE specialist (the experimental group) versus a trained classroom teacher (the control group) and found the experimental group to be significantly more active and to possess superior physical-condition attributes, such as abdominal strength and endurance.

Conclusions

Studies such as this provide insight into overall activity levels of young Polish children and, equally important, suggest questions for further research. For example, is declining activity the result of choosing sedentary alternatives such as watching television and playing video games over physical activity? In which activities are children in these age ranges engaging? How do we get young children engaged in activities that are culturally appropriate and lead to better health outcomes? Are appealing community-based programs available in sufficient numbers? Do parents customarily encourage physical activity? Answers to questions such as these are needed if physical educators are to design creative programs sufficiently attractive to young children to entice behavior changes.

Acknowledgment: This research was funded by the state research grant: "Physical activity in human life No. CEZ: J14/98:155100015."

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Karel Fromel

Academy of Physical Education, Katowice, Poland

Jiri Stelzer

Valdosta State University, GA, USA

Dorota Groffik

Academy of Physical Education, Katowice, Poland

James Ernest

Valdosta State University, GA, USA

Table 1
Physical Characteristics of the Participants

Groups      N    Age (years)   Weight (kg)

                  M      SD      M      SD

Girls-KG    35   6.49   0.35   23.84   4.99
Boys-KG     36   6.48   0.45   23.74   4.11
Girls--I   113   7.57   0.34   25.88   4.99
Boys--I    131   7.64   0.33   26.52   5.67

                            BMI (kg x
Groups     Height (cm)     [m.sup.-2])

             M       SD      M      SD

Girls-KG   122.63   5.66   15.74   2.39
Boys-KG    122.78   4.58   15.68   2.07
Girls--I   125.94   5.75   16.21   2.21
Boys--I    126.39   6.28   16.46   2.43

Note. M = mean; SD = standard deviation, KG--Kindergarten, I--1st grade

Table 2
Active Energy Expenditure (kcal x [kg.sup.-1] x [day.sup.-1]) and
Recorded PA (min/day) of Girls and Boys in the Last Year of
Kindergarten and in the 1st Grade

Variable             Kindergarten

              G (n = 35)       B (n = 36)

              M       SD       M       SD

AEE          8.80    2.07    12.15    3.35

AEESD        9.37    2.26    12.18    3.73

AEEFD        7.38    3.14    12.08    4.54

Total      128.01   54.49   118.49   50.76
recorded
PA

Variable              1st Grade

             G (n = 113)      B (n = 131)

              M       SD       M       SD

AEE          8.63    3.33    13.47    4.45

AEESD        9.25    4.02    13.90    4.72

AEEFD        7.08    3.96    12.14    5.61

Total      109.05   53.88   109.29   60.47
recorded
PA

Note. G = Girls; B= Boys, M = mean; SD = standard deviation,
AEE = active energy expenditure, AEESD = active energy expenditure
on school days, AEEFD = active energy expenditure on free days,
Recorded PA = number of minutes per day.

Figure 1
Total Energy Expenditures (kcal) of Different PA of Girls and Boys
in the 1st Grade of Elementary School

Kcal               Girls       Boys

Lesson               36          31
Lesson PE            70          76
Recess               24          26
Recess-summary       91         104

Note.

Lesson--average calories expenditure (seven days) in one lesson
(except PE).

Lesson PE--average calories expenditure (seven days) in one PE
lesson.

Recess--average calories expenditure (seven days) during one break.

Recess--summary--average calories expenditure (seven days) during
all breaks in one day.

Note: Table made from bar graph.

Figure 2
Recorded PA of Girls (min x [week.sup.-1])

                   kindergarten     first grade

walking            280              241
sport games        201              60
outdoor PA         182              82
aerobic-dance      107              68
home PA            85               89
fitness            46               54
games with PA      15               44
swimming           0                20

Note: Table made from bar graph.

Figure 3
Recorded PA of Boys (min x [week.sup.-1])

                   kindergarten     first grade

walking            298              302
sport games        158              76
outdoor PA         155              81
aerobic-dance      75               29
home PA            43               96
fitness            30               47
games with PA      40               52
swimming           8                24

Note: Table made from bar graph.