Diagnostic analysis of physical fitness and overweight related to adolescent health: Evaluation criteria for health

Abstract

Objective

The aim of this study was to determine the association between physical fitness, socio-demographic factors and overweight prevalence of adolescent schoolchildren from urban and rural cities.

Methods

The study population was made up of 377 male and female teenagers 14–17 years, enrolled in randomly selected public schools in urban and rural areas the northern Brazil. Socioeconomic status, flexibility, abdominal strength, endurance and cardiorespiratory fitness were measured.

Results

The students from urban areas had a 55% (confidence interval of 95% = 1.12–2.12) more likely inadequacy physical quality and area of residence when compared to the rural area students. There was an association between muscular strength and endurance and area of residence. These odds ratio results demonstrated that the chances the students presented with inadequacy in this variable were 8.99 (confidence interval of 95% = 1.12–72.30) times higher among schoolchildren in rural compared to urban area. It was observed that 25.1% of teenagers found themselves with inadequate body composition, and the proportion of teenagers with inadequate body composition was higher (p < 0.05) for males (32.3%) compared to females (18%).

Conclusion

It was concluded that there was an association between components of health related fitness and area of residence in the current study groups.

Resumen

Objetivo

El objetivo de este estudio fue determinar la asociación entre la condición física, los factores sociodemográficos y la prevalencia de sobrepeso en adolescentes escolares de municipios urbanos y rurales.

Método

La población de estudio estaba compuesta por 377 adolescentes de ambos sexos de 14–17 años, escolarizados en centro públicos seleccionados al azar en zonas urbanas y rurales del norte de Brasil. Se midieron el estatus socioeconómico, la flexibilidad, la fuerza abdominal, la resistencia y la capacidad cardiorrespiratoria.

Resultados

Los estudiantes de zonas urbanas tenían un 55% (intervalo de confianza del 95% = 1.12–2.12) más de probabilidades de contar con una condición física inadecuada y de residir en una zona inapropiada, en comparación con los estudiantes de zonas rurales. Había una asociación entre la fuerza muscular y la resistencia y la zona de residencia. Estos resultados de la odds ratio demostraron que las posibilidades de los estudiantes que presentaron deficiencias en esta variable fueron 8.99 (intervalo de confianza del 95% = 1.12–72.30) veces mayor entre los escolares de las zonas rurales en comparación con los de zonas urbanas. Se observó que el 25.1% de los adolescentes opinaban que tenían una composición corporal inadecuada y que la proporción de adolescentes con composición corporal inadecuada fue mayor (p < 0.05) en los hombres (32.3%) en comparación con las mujeres (18%).

Conclusión

Se concluyó que había una asociación entre los componentes de la condición física relacionada con la salud y el área de residencia en los grupos estudiados.

Resumo

Objetivo

O objetivo deste estudo foi determinar a associação entre aptidão física, fatores socio demográficose prevalência de sobrepeso de escolares adolescentes de cidades urbanas e rurais.

Método

A população do estudo foi composta por 377 adolescentes do sexo masculino e feminino, com idade entre 14–17 anos, que foram selecionados aleatoriamente e estudavam em escolas públicas das zonas urbanas e rurais do norte do Brasil. Foram avaliados o nível socioeconômico, flexibilidade, força abdominal, resistência e aptidão cardiorrespiratória.

Resultados

Os alunos das zonas urbanas tiveram 55% de probabilidade maior em possuir uma aptidão física inadequada, e residir em uma área inadequada quando comparados com os estudantes da zona rural (intervalo de confiança de 95% = 1.12–2.12). Houve uma associação entre força e resistência muscular com a área de residência. Estes resultados da odds ratio demonstram que as chances de os estudantes apresentarem inadequação nesta variável foram de 8.99 (intervalo de confiança de 95% = 1.12–72.30) vezes maiores entre crianças em idade escolar na zona rural, em comparação com as de zona urbana. Observou-se que 25.1% dos adolescentes encontraram-se com a composição corporal inadequada e esta proporçãofoi maior (p < 0.05) para o sexo masculino (32.3%) em relação ao sexo feminino (18%).

Conclusão

Concluiu-se que houve uma associação entre os componentes da aptidão física relacionada com a saúde e área de residência nos grupos estudados no presente estudo.

Introduction

Regular practice of physical activity can contribute to the improvement of various components of health-related physical fitness, such as strength, muscular endurance, cardiorespiratory endurance, flexibility and body composition.¹ These improvements may favor mainly the control of body fat, but also maintain or improve neuromotor function.² These changes facilitate performance in various tasks of everyday life and, consequently, provide better health and quality of life.^1,2

In contrast, reduced levels of physical activity seems to favor the gradual development of many chronic degenerative disorders such as obesity, diabetes, cardiovascular disease, hypertension, and many others, at increasingly earlier ages.^3,4 The high prevalence of obesity in children and adolescents is a serious public health concern. According to the International Obesity Task Force, at least 177 million children and adolescents are overweight or obese worldwide. This number equates to greater than one in ten youth being overweight or obese globally.⁵

A study conducted by Wang et al.⁶ in countries with different stages of socioeconomic development revealed a significant increase in the prevalence of overweight children and adolescents in recent decades. Among adolescents, the observed increases in overweight of significant magnitude were: 62% in the United States (16.8–27.3%) and 240% in Brazil (from 3.7% to 12.6%). However, most studies involving the different components of physical fitness have adopted traditional analytical procedures based on normative data, which greatly limits a more careful analysis of data.⁷

Little is known about the relationship between different elements of physical fitness and overweight or obesity in Brazilian adolescents. For example, we do not know if lack of flexibility, muscular endurance of the abdominal muscles, or aerobic fitness, which are associated with poor physical function and health in adolescents, are related to degree of overweight in this population. Similarly, there are few studies on the interaction between cardiovascular fitness and related indicators of health in adolescents who are obese.⁷

Accordingly, the aim of this study was to determine the association between of physical fitness, socio-demographic factors and overweight prevalence of adolescent schoolchildren ages 14–17 years from urban and rural areas in Tucuruí-Para in northern Brazil.

Method

Sample

The study population was made up of 377 male (n = 210) and female (n = 167) adolescents ages 14–17 years, enrolled in randomly selected public schools in urban and rural areas of the municipality of Tucuruí-Para in Brazil. The volunteers were informed about the study and signed the authorization in accordance with Resolution 466/2012 of the Brazilian National Health Council, in agreement with the ethical principles contained in the Declaration of Helsinki (1964, revised in 2008), the “World Medical Association.” The procedures were approved by the University Center of Triangulo Mineiro Ethics Committee.

The exclusion criteria were: individuals less than 14 years of age or greater than 17 years of age, individuals unable to participate in evaluations for any physical or mental reasons, individuals not residing in the city of Tucuruí, PA, and individuals not having the consent of parents or guardians to participate in the study.

Experimental design

Initially, it was informing all study procedures for the guardians of the participants. Then the questionnaire was applied to analyze the socio-economic classification. After the questionnaire anthropometric and neuromotor tests was carried out in the open gymnasium according to the Cahper.⁸

The socioeconomic rating consisted of two questions from the Economic Classification criterion of Brazil, adopted by the Brazilian Association of Population Studies – BAPS.⁹ The two questions were used in order to classify the economic status of the sample on the number and type of consumer items in the residence and the level of formal education of the heads of the family. The categorization of the subjects was made on an ordinal scale according to the score as follows: A1 (30 –34 points), A2 (25–29 points), B1 (21–24 points), B2 (17–20 points) C (11–16 points), D (6–10 points), E (00–05 points).

To collect anthropometric data of body weight, height, waist circumference, and skinfold thickness, the following procedures were performed: The teenagers were wearing light clothes (shirt and shorts) without shoes. The measurement of height and weight were determined using a balance (Filizola, Brazil). Waist circumference was measured twice at the level midway between the lowest rib margin and the iliac crest. The skinfolds (triceps, biceps, subscapular, suprailiac, and calf) were determined using Sanny calipers (Sanny, Brazil) with a scale of 0.1 mm, following the recommendations of Gordon et al.¹⁰

To obtain the results of the Physical Fitness tests, which served as the basis of health assessment, the Physical Best test battery was used and consisted of the three following tests: flexibility, muscular strength/endurance of the abdomen, and cardiorespiratory fitness.⁸

Flexibility was measured using the Test of Sit-and-Reach modified to record the maximum distance achieved in trunk flexion at the hip in a sitting position. The sit-and-reach results were evaluated with the table, which classifies the results into three categories of health risk: low fitness, recommended range of health, and athleticism. The instrument used was a Bank of Wells with a scale in inches.¹¹

Abdominal test was designed to assess abdominal muscle strength and endurance. The participants were initially in a supine position with knees bent and the soles of the feet facing the ground. Arms were crossed over the anterior chest, with the palms facing the chest at shoulder height. To perform the test, participants raised the trunk until there was contact between the anterior thighs and forearms then immediately returned to the initial position. These movements were repeated for 1 min, with the goal being to achieve the greatest possible number of repetitions in the stipulated time. According to Safrit¹² the validity and reliability coefficient is 0.68–0.94 for this test.

The objective of the test was to determine aerobic endurance, which was assessed using a 1600 m run/walk. It is recommended that twelve individuals run simultaneously for this test. Participants were instructed that walking is allowed, but the goal is to cover the required distance in the shortest time possible (recorded in minutes and seconds).

The components of health-related physical fitness (HRPF) were evaluated against the criteria referenced (CR) by Cahper,⁸ as shown in Tables 1 and 2.

Table 1.

Reference criteria, established by American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD) in 1988 for a desirable health-related physical fitness – girls and boys.

Components of Health-Related Physical Fitness
Years	Girls	Boys	Girls	Boys	Girls	Boys	Girls	Boys
	1600 m (min/seg)		Body Mass Index (kg/m^2)		Sit and reach (cm)		Abdominal (maximum number of repetitions)
14	10:30	7:45	17–24	16–24	25	25	35	40
15	10:30	7:30	17–24	17–24	25	25	35	42
16	10:30	7:30	17–24	18–24	25	25	35	44
17	10:30	7:30	17–25	18–25	25	25	35	44

Table 2.

Determination of body composition suitable for health.

Punctuating the components of body composition
BMI appropriate and the sum of five skinfold appropriate.	8 points
BMI not suitable and sum of five skin folds appropriate.	8 points
BMI appropriate and the sum of five skin folds unsuitable.	3 points
BMI not suitable and sum of five skinfold not appropriate.	0 points
Body Weight appropriate and the sum of two skinfolds appropriate.	8 points
Body Weight appropriate and the sum of two skinfolds unsuitable.	4 points
Body weight not suitable and sum of two skinfolds appropriate.	2 points
Body weight not suitable sum of two skinfolds unsuitable.	0 points

Interpreting the points
16 points	Excellent
12 points	Very good
7–11 points	Good
4–5 points	Regular
0–3 points	Improve

Source: Canadian Society for Exercise Physiology (1998).

Statistical analysis

Data were treated as descriptive statistics (frequency distribution) and inferential statistics (chi-square and logistic regression). We used measures of central tendency: mean (M) and standard deviation (SD). The chi-square test was used to assess differences between proportions. Logistic regression was used to assess the association between inadequate outcomes (flexibility, muscular strength and endurance and cardiorespiratory fitness) and the independent variables (gender, age, body mass index (BMI), area of residence and nutritional status). In the crude analysis, we calculated the odds ratios (OR) and confidence interval of 95% (95% CI) for each independent variable in relation to a reference category. Subsequently, the model was adjusted for all independent variables. To check normality, Kolmogorov–Smirnov was used, in view of the size of the sample. For normally distributed data, we used analysis of variance (two-way ANOVA) for comparisons between gender and age. The post hoc Bonferroni was employed to identify specific differences in those variables, where the F values found were superior to the criterion established for statistical significance (p < 0.05). We used SPSS for Windows 20.0

Results

Table 3 shows the anthropometric characteristics of students (mean, standard deviation, and statistical F) according to gender and chronological age. For the isolated effect of gender (p < 0.05) and the isolated effect of age (p < 0.05) statistical differences were found in body mass and height. Also, the interaction between gender and age on body mass and height was observed (p < 0.05).

Table 3.

Anthropometric characteristics of schoolchildren according to gender and age.

Years	Gender	Body weight (kg)	Stature (cm)	BMI (kg/m^2)
14	Male	47.92 ± 9.72^a	162.43 ± 8.84^a	18.62 ± 3.05^a
	Female	47.50 ± 6.30^A	157.36 ± 6.68^A	18.95 ± 2.27^A
15	Male	56.10 ± 7.96^bc	158.30 ± 7.76^bc	19.63 ± 2.31^ab
	Female	50.82 ± 7.51^B	162.68 ± 6.70^AB	19.95 ± 2.69^AB
16	Male	58.67 ± 7.86^cd	172.87 ± 5.97^cd	19.77 ± 2.37^b
	Female	52.56 ± 6.92^B	160.90 ± 6.70^B	21.04 ± 2.53^BC
17	Male	61.99 ± 10.93^d	171.92 ± 7.99^d	20.76 ± 3.29^b
	Female	54.04 ± 6.02^B	161.04 ± 6.09^AB	21.08 ± 2.32^C
F gender		54.154	210.040	1.145
F years		33.939	27.996	13.948
F gender × years		4.041	9.876	0.197

BMI: Body Mass Index.

a,b,c – comparing ages in males.

A,B,C – comparing ages in females.

AA,BB,CC – no significant difference between the ages (p > 0.05).

AB,BC,ab,bc – significant difference between the ages (p < 0.05).

Table 4 shows the values (M, SD and statistical F) regarding the test of HRPF in adolescents by gender and chronological age. There were only isolated effects of gender (p < 0.05) in the abdominal and cardiorespiratory fitness tests.

Table 4.

Performance of schoolchildren in motor tests according to gender and age.

Years	Gender	Flexibility (cm)	Abdominal (Rep)	T1600 (m)
14	Male	26.37 ± 6.10	25.88 ± 6.80	8.31 ± 2.29
	Female	25.33 ± 7.99	16.67 ± 6.88	11.67 ± 2.48
15	Male	26.97 ± 7.67	26.57 ± 7.36	9.05 ± 2.67
	Female	26.04 ± 8.12	18.77 ± 7.80	12.10 ± 3.60
16	Male	25.77 ± 8.36	25.79 ± 8.10	8.61 ± 2.21
	Female	25.98 ± 8.22	17.39 ± 7.90	11.67 ± 3.12
17	Male	25.53 ± 8.08	25.97 ± 8.69	9.01 ± 2.67
	Female	24.99 ± 7.32	17.87 ± 7.38	11.97 ± 3.07
F gender		0.949	177.373^*	173.036^*
F age		0.529	0.856	1.599
F gender × age		0.239	0.177	0.080

T1600: Test 1600 m. Rep: repetitions; F: statistical F.

*

p < 0.05 comparison between genders.

Table 5 shows the proportion of students with inadequacy in each component of HRPF according to socio-demographic variables (gender, age, socioeconomic status (SS), area of residence and BMI).

Table 5.

Proportion of inadequacy of the components of physical fitness in students based on gender, age, economic level, area of residence, and nutritional status.

	Flexibility (cm)	Muscular Strength/abdominal (Rep)	Cardiorespiratory fitness (ml/(kg × min))
Gender
Male	39.1	97.7	35.3
Female	42.4	99.2	35.5
p	0.409	0.138	0.975
Age group
14–15	37.8	98.8	35.1
16–17	44.5	98.3	35.8
p	0.090	0.634	0.850
Economic level
A + B	37.7	98.7	41.6
C	39.9	98.2	31.8
D + E	44.0	98.8	34.8
p	0.417	0.852	0.147
Area of domicile
Urban	46.5^*	97.3^*	43.1^*
Rural	36.0	99.7	28.4
p	0.008	0.013	<0.001
Body mass index
Normal weight	39.2	98.8	35.5
Underweight	46.2	97.8	38.5
Overweight	49	98	28.6
p	0.231	0.725	0.503

Rep: repetitions; p: p value.

*

p < 0.05 (ANOVA Two Way, Post Hoc Bonferroni).

Association was found between flexibility, muscular strength and endurance, and cardiorespiratory fitness (p < 0.05). In testing flexibility and cardiorespiratory fitness, a higher proportion of inadequacy was found in the urban area schools, while the highest proportion of inadequacy in muscular strength and endurance was found in the rural area schools.

The association between the inadequate flexibility and associated factors are presented in Table 6. Association was found between physical quality and area of residence, in which the students from urban areas had a 55% (95% CI = 1.12–2.12) more likely inadequacy of this variable when compared to the rural area students. When the analysis was adjusted for all variables, it was noticed that the area of residence remained associated with inadequate flexibility. These results revealed that the students from urban areas were 56% (95% CI = 1.12–2.16) more likely to have inadequate flexibility as compared to the rural school children.

Table 6.

Odds ratios for inadequate flexibility in relation to gender, age, economic level, area of residence, and body mass index.

	OR (CI95%)	p	OR* (CI95%)	p
Gender
Male	1		1
Female	1.15 (0.83–1.58)	0.409	1.14 (0.80–1.64)	0.468
Age group
14–15	1		1
16–17	1.39 (0.96–1.81)	0.090	1.49 (0.74–3.00)	0.259
Economic level
A + B	1		1
C	1.01 (0.85–2.08)	0.660	0.98 (0.62–1.56)	0.945
D + E	1.30 (0.83–2.68)	0.210	0.88 (0.38–2.08)	0.778
Area of domicile
Urbana	1.55 (1.12–2.12)	0.008	1.56 (1.12–2.16)	0.008
Rural	1		1
Body mass index
Normal weight	1		1
Underweight	1.32 (0.85–2.08)	0.217	1.32 (0.84–2.09)	0.225
Overweight	1.49 (0.83–2.68)	0.189	1.51 (0.84–2.74)	0.172

OR: odds ratio. OR * adjusted for all variables in the table; p: p-value.

Table 7 presents the results of a logistic regression analysis test of muscular strength and endurance in relation to socio-economic factors. There was an association between muscular strength and endurance and area of residence. These odds ratio results demonstrated that the chances of the students presenting with inadequacy in this variable was 8.99 (95% CI = 1.12–72.30) times higher among schoolchildren in rural compared to schoolchildren in urban areas. When the analysis was adjusted, it was realized that the area of residence remained associated with the physical quality, in which the students from rural areas were almost ten times (95% CI = 1.20–83.20) more likely to have inadequate muscle strength and endurance compared to students in urban areas.

Table 7.

Odds ratios for inadequate abdominal strength/endurance in relation to gender, age, economic level, area of residence, and nutritional status.

	OR (CI 95%)	p	OR* (CI 95%)	p
Gender
Male	1		1
Female	2.75 (0.68–11.11)	0.155	3.21 (0.64–16.26)	0.158
Age group
14–15	1.38 (0.37–5.18)	0.635	1.34 (0.15–12.35)	0.797
16–17	1		1
Economic level
A + B	1		1
C	0.72 (0.13–3.98)	0.700	0.73 (0.09–5.76)	0.764
D + E	1.08 (0.18–6.56)	0.930	0.79 (0.04–17.40)	0.880
Area of domicile
Urbana	1		1
Rural	8.99 (1.12–72.30)	0.039	9.99 (1.20–83.20)	0.033
Body mass index
Normal weight	1		1
Underweight	0.55 (0.11–2.79)	0.475	0.55 (0.10–2.88)	0.477
Overweight	0.60 (0.07–5.07)	0.640	0.68 (0.08–5.99)	0.727

OR: odds ratio. OR * adjusted for all variables in the table; p: p-value.

Table 8 shows the association of cardiorespiratory fitness factors associated with poor schoolchildren. As with other variables, cardiorespiratory fitness was associated with area of residence. The OR findings in Table 8 indicated that children living in urban areas had 91% more risk of inadequate cardiorespiratory fitness than those from rural areas.

Table 8.

Odds ratio for inadequate cardiorespiratory fitness in relation to gender, age, economic level, area of residence, and nutritional status.

	OR (IC95%)	p	OR* (IC95%)	p
Gender
Male	1		1
Female	1.00 (0.72–1.40)	0.975	1.07 (0.74–1.57)	0.710
Age group
14–15	1		1
16–17	1.03 (0.74–1.43)	0.850	1.60 (0.77–3.29)	0.200
Economic level
A + B	1.33 (0.88–2.01)	0.173	2.04 (0.85–4.93)	0.111
C	0.88 (0.60–1.28)	0.496	1.15 (0.57–2.32)	0.689
D + E	1		1
Area of domicile
Urbana	1.91 (1.37–2.67)	<0.001	1.91 (1.36–2.69)	<0.001
Rural	1		1
Body mass index
Normal weight	1		1
Underweight	1.13 (0.71–1.80)	0.592	1.10 (0.69–1.77)	0.667
Overweight	0.72 (0.38–1.39)	0.332	0.72 (0.37–1.39)	0.333

OR: odds ratio. OR* adjusted for all variables in the table; p: p-value.

Fig. 1 shows the proportion of adolescents who did not meet the health criteria established for body composition. The results showed that 25.1% of teenagers find themselves with inadequate body composition, with the proportion of teenagers with inadequate body composition being higher (p < 0.05) for males (32.3%) than for females (18%).

Fig. 1.

Proportion (%) of students who did not meet the healthy criteria established for body composition. * p < 0.05 for comparison between genders.

Fig. 2 shows the proportions of adolescents who did not meet the criteria established for each test investigated, for flexibility, that 40.8% of adolescents did not meet the criteria for health. Significant differences were found between genders at the age of 14 years, with the proportion of inadequacy being higher in females than in males (p < 0.05). In the test of muscular strength and endurance, we observed that 98.5% of adolescents ranked below the cutoff for health. Significant differences were found between genders at the age of 15 years (p < 0.05), with a higher proportion of female adolescents (99.2%) than male adolescents (97.7%) being below the recommended minimum criteria for health. In cardiorespiratory fitness, 35.4% of adolescents had performance below the established cutoff for health. Gender differences in the proportions were observed at ages 14 and 16 years. These findings indicate that a greater proportion of adolescent males than adolescent females at the age of 14 years and a greater proportion of females than males at the age of 16 did not meet the minimum criteria recommended for health.

Fig. 2.

Not meeting criteria for health (%) of students who did not meet the criteria for health established for each test according to gender and age. * p < 0.05 for comparison between genders.

Regarding the general classification for health, there was a high prevalence of adolescents who did not meet both criteria established for health as determined from the three motor tests. These results indicated that 99.6% of teenagers have not reached the desired level for health.

Discussion

The aim of this study was to determine the associations between physical disability, socio-demographic factors, and nutritional status of schoolchildren in Tucuruí, PA. This is the first study of this kind to be conducted in the northern Brazil. Flexibility, muscular strength and endurance, and cardiorespiratory fitness were associated with the area of domicile. The study revealed that most inadequate flexibility and cardiorespiratory fitness were observed among schoolchildren in urban areas, a fact that is proven by the lifestyle which children in urban areas have in relation to children in rural areas. In contrast, most inadequate abdominal strength was observed in those children from rural areas. A study of adolescents in rural and urban areas in the north and west of Santa Catarina (Southern, Brazil) reported a greater inadequacy of muscular strength and endurance and cardiorespiratory fitness in adolescents in urban areas, while flexibility was similar between areas of residence.¹³

Since urban adolescents have lower HRPF in the areas of flexibility and cardiorespiratory fitness than their rural peers, it is assumed that the lifestyle adopted by the schoolchildren in this area of residence contributes significantly to the performance of the tests. Despite not having been verified, the possible factors that influence the performance on the tests are the labor activities, customs and habits that are cultivated in the rural sample, and that these interact positively with HRPF. However, other habits and practices with little energy expenditure that predominate in the urban areas tend to negatively influence health-related physical fitness in this sample city. Even though mechanization has decreased energy expenditure of residents in agricultural communities, caloric expenditure can be considered much higher in rural activities than in activities common in urban areas.¹⁴

In the flexibility test, the students of the urban area had a 56% greater chance of inadequacy in relation to the rural area students. This result is explained by the fact that the students in rural areas still do not have access to technological advances, using active transportation (walking or cycling) in commuting to school, and work in agriculture, mostly subsistence, in which agricultural machinery is not often used. Furthermore, the municipality of Tucuruí-PA does not offer Internet throughout the countryside, and access to television is only possible through satellite dishes, which limits access to passive leisure activities. In contrast, in urban areas the population has ready access to passive forms of leisure activities resulting from technological developments (TV, Internet, Lan House).

Low levels of flexibility are worrying, as low levels of flexibility increase the risks of pain in the lumbar region, a higher incidence of postural deviations, and poor academic performance.^15,16 A longitudinal study in Finland found that, after 25 years, children with low levels of flexibility during school reported greater back pain in adulthood.¹⁶

With respect to abdominal strength and endurance, students from rural areas had a ten times higher chance of inadequacy in this measure than the inner city schoolchildren. Similar results were found in a study of schoolchildren in southern Brazil, where the students from rural areas had the worst performance in the test of abdominal strength and endurance.¹⁷ In contrast, studies of rural and urban adolescents living northwest of Santa Catarina and Rio Grande do Sul were reported to have worse performance on abdominal strength tests than adolescents in urban areas.¹⁸

In the cardiorespiratory test, students in the urban area had 91% higher chance of inadequacy than those in rural areas. These findings are consistent with other studies conducted with samples of Brazilian children and adolescents.^17,18 Another study reporting worse performances of students from urban areas compared to rural areas was conducted on nine to twelve year old children in Mexico.¹⁹ Low levels of cardiorespiratory fitness is worrisome, especially because it is association with high levels of Metabolic Syndrome risk: high cholesterol and triglycerides, high blood pressure, insulin resistance, and increased risk for obesity.^20–23

Among the independent variables (gender, age, SS, area of residence and BMI), the only one that was associated with components of HRPF was the area of domicile, which explained most of the variation. SS, which may be taken as contextual variables, was not associated with the components of HRPF. This suggests that performance on tests that make up the HRPF of the school children of Tucuruí-PA may be more related to environmental features associated with living in a given area.

The results of this study revealed an association between components of HRPF and area of residence. These results indicate that the students from rural areas had better cardiorespiratory fitness and flexibility, while better abdominal strength and endurance was found in those of the urban area. Therefore, the school can play a key role in the development of HRPF through physical education classes, since this location is perhaps the only location where we have all adolescents participating in programs oriented toward exercise.

It was observed that the smaller schools are not able to offer these programs, because they do not have adequate physical spaces, or the materials needed for physical education.

Considering the low proportion of students meeting adequate health in either setting, it is important to develop an integrated program of physical activity where students, family members, teachers, and administrators play an active role in promoting physical activity and healthy lifestyles.

Increasing physical activity to nationally recommended levels is a challenge for many middle and high school administrators across the nation. Even smaller amounts of physical activity in school may decrease obesity levels significantly. It is essential to consider children at high risk for obesity, such as minority females, when developing such physical activity programs.

Ethical disclosures

Protection of human and animal subjects

The authors declare that the procedures followed were in accordance with the regulations of the relevant clinical research ethics committee and with those of the Code of Ethics of the World Medical Association (Declaration of Helsinki).

Confidentiality of data

The authors declare that they have followed the protocols of their work center on the publication of patient data.

Right to privacy and informed consent

The authors have obtained the written informed consent of the patients or subjects mentioned in the article. The corresponding author is in possession of this document.

Conflicts of interest

The authors have no conflicts of interest to declare.