PHYSICAL FITNESS AND ACTIVITY CHARACTERISTICS OF HOME SCHOOLED CHILDREN

Dale DeVoe, Ph.D.
Cathy Kennedy, Ph.D.
Crystal A. Lloyd, M.S.
Department of Exercise and Sport Science
Colorado State University
Fort Collins, Colorado 80523

Keywords: Homeschooling, home schooling, home education, physical fitness, physical activity.

The promotion of health and wellness is increasingly becoming one of the most important facets for the enhancement of the quality of life and in the prevention of many hypokinetic diseases. Cardiovascular disease (CVD) encompasses the most prevalent of the degenerative diseases in the United States today, accounting for 42.2% of total deaths per year. CVD is commonly associated with such factors as hypertension, smoking, obesity, abnormal cholesterol profiles, and a sedentary lifestyle (Hoeger & Hoeger, 1994). Health and habitual exercise is of interest because it appears to minimize the morbidity and mortality rates affiliated with heart disease and its associated risk factors (Paffenbarger & Hyde, 1984). Diseases of the cardiovascular system are commonly thought to involve the “older” population when, in fact, risk factors have been detected in many children. Expanding the promotion of exercise in children is becoming an increasing area of study. Most of the interest in recent years is due to the fact that children of all ages are more over-fat than they were 20 years ago (Gortmaker, Dietz, Sobol, & Wehler, 1987) and obesity is a significant risk factor for hypertension, heart disease, some forms of cancer, diabetes, and premature mortality (Serdula, Ivery, Coates, Freedman, Williamson, & Byers, 1993).
It is clear that researchers, as well as parents, have been very interested in their home schooled children’s total development—academic (cognitive), social and emotional (affective), and spiritual. However, one very important part of the whole development model that needs further examination is the physical.
The benefits of physical activity on a child’s health are well documented. Children who are active and physically fit have fewer cardiovascular risk factors than less active children. The risk factors associated with coronary heart disease (CHD) are reduced by regular physical activity in adults as well as in children (Ross & Pate, 1987). Children who are physically active and fit have lower blood pressures

(Fraser, Phillips & Harris, 1983; Fripp, Hodgson, Kwiterovich, Werner, Schuler & Whitman, 1985),
higher levels of HDL cholesterol (Durant, Linder & Mahoney, 1983; Gilliam & Burke, 1978; Thorland & Gilliam, 1981), and have a lower percent of body fat (Sallis, Buono, Roby, Micale & Nelson, 1993) than children who are less active and fit. Physical activity is also included in interventions for treating diabetes mellitus, controlling obesity, and other clinical conditions in children (Sallis et al., 1993).
McGinnis (1987) states that physical activity patterns and attitudes are often influenced in important ways by factors presented before age 10. The National Children and Youth Fitness Study II found that the physical activity patterns of children, as reported by their parents and teachers, were significantly related to their physical fitness (Pate & Ross, 1987). This study revealed a positive correlation between performance on the mile walk/run test and the following: (1) more participation in community based physical activities, (2) less television watching, (3) receiving more physical education instruction from a specialist and taking physical fitness tests, and (4) high activity ratings by parents and teachers.  A positive correlation was also shown to exist between parental physical activity and their child’s body composition. Parents who were more active and exercised more frequently had children who were leaner (Pate & Ross, 1987).  This study strongly suggests that physical education programs, parental activity habits, and out-of-school activity habits have a significant impact on body composition and cardiorespiratory endurance.
A positive correlation is generally found between parent health behaviors (e.g., smoking, diet, dental care, seat belt use) and the behavior of their children (Dielman, Leech, Becker, Rosenstock, Horvath & Radius, 1982; Perry, Luepker, Murray, Hearn, Halper, Dudovitz, Maile & Smyth, 1989; Perusse, LeBlanc & Bouchard, 1988). A relationship between parental attitudes about exercise and children’s behaviors exists (Dishman, Sallis & Orenstein, 1985; Dielman et al., 1982; McMurray, Bradley, Harrell, Bernthal, Frauman & Bangdiwala, 1993). A high level of family support for exercise has been found to improve exercise compliance (Dishman et al., 1985). McMurray et al. (1993) reported a slight significance between parent’s activity levels, attitudes and habits and their children’s aerobic power. In particular, the mother’s attitudes toward exercise were significantly associated with her child’s VO2 max.
The lack of attention given to physical fitness in home school literature raises two questions: how important is physical fitness to the home school family, and how physically fit are home schooled children?
Fitness levels of youth, in the last decade, are on a steady decline (Pierce, Butterworth, Lynn, O’Shea, & Hammer, 1992) with one-third to upwards of two-thirds of the younger population being unfit (Kuntzleman, 1993). Intervention into a child’s lifestyle habits may aid with the prevention of onset of the risk factors that can lead to cardiovascular disease. Attempts have been made at improving the fitness of children, usually within the public school environment, where increased knowledge and physical fitness and activity are readily attainable (Butcher, Frank, Harsha, Serpes, Little, Nicklas, Hunter, & Berenson, 1989; Nader, Sallis, Patterson, Abramson, Rupp, Senn, Atkins, Roppe, Morris, Wallace, & Vega, 1989). Outside of the conventional school structure, however, modification of lifestyle habits is not easily maintained (Dishman, Sallis, & Orenstein, 1985). Increased awareness toward participation in activities for home schooled youth will indeed aid in their health and wellness. The purpose of this study was to assess various physical fitness and activity variables among home schooled children, and compare their values with those of national averages.

Procedures

Subjects (N = 51) were healthy children (male and female), ages 6 to 18, who were being schooled at home. Each subject participated in a fitness assessment evaluation which included flexibility, right and left hand grip strength, VO₂ -max test, and anthropometric tests including height, weight, blood pressure and body fat percentages. A self reported activity (SRA) questionnaire was used to assess their participation in selected activities.
The measures utilized in this study were selected in order to assess the following areas of health-related fitness: flexibility, cardiorespiratory endurance, muscular strength, and body  composition. Height (cm) and weight (kg) were measured by a pre-calibrated portable stadiometer. Blood pressure was taken on the right arm, at the level of the heart, with a Tycos aneroid sphygmomanometer with cuff size appropriate for a child’s upper arm length and circumference.
Hamstring flexibility was determined using the Lafayette flexibility tester. The Sit-and-Reach Test has been validated by comparing it with several other types of flexibility tests, with validity coefficients ranging between .80 and .90. The subject would sit on the floor with legs extended and feet flat against the rubber pads on the unit. They would reach forward, with their fingertips pressing against the slide bar, and move the slide bar up the scale as far as possible. Three trials were attempted and the farthest reach was recorded to the nearest one-half inch.
Hand grip strength was assessed in both the right and left hands with the use of a Lafayette hand grip dynamometer. The intra- and inter-rater reliability of handheld dynamometers is high (>.90) with equivocal validity. The dynamometer was adjusted to fit each subject’s handgrip size. While standing, the child held the dynamometer at their side, squeezing the grip as hard as possible without moving their arm. Three trials were attempted for each hand with the best score being recorded.
Maximal oxygen consumption was estimated using the “Eurofit” submaximal cycle ergometer test on a Bodyguard Cycle Ergometer 990. The Eurofit submaximal cycle ergometer test has been validated for use with correlation ranging from .57 to .88 and is recommended for testing of children. The test consisted of three stages, each 2 minutes long. The stages remained constant for each subject at 25, 50 and 75 watts bringing the heart rate close to 170 b.p.m. as proposed by McMurray, Bradley, Harrell, Bernthal, Frauman, and Bangdiwala (1993). Heart rate was recorded, using a Polar Pacer Vantage XL heart rate monitor, in 5-second intervals including 30 seconds of resting data and 90 seconds of recovery data. VO₂ max was estimated, by second-minute heart rates at each workrate, through individual regression equations. The workrate corresponding to a maximum heart rate, resting oxygen uptake, gender, and body mass (Shepard, Allen, Bar-or, Davies, Degre, Hedman, Isha, Kaneko, LaCour, diPramperc, & Seliger, 1969) and age (Mocellin, Lindemann, Rutenfranz, & Sbresny, 1971) were used as correction factors.
The use of the skinfolds to estimate body fatness in the children and youth conformed to skinfold test assessments produced by Lohman (1987). The skinfold measurement procedure developed by Lohman (1987) has a validity coefficient of  .90 with hydrostatic weighting and inter-tester reliability over .95 with experienced testers. Skinfold measurements were taken at two sites, triceps and medial calf muscles, using a Lange skinfold caliper. Tricep measurements were taken on a vertical fold raised midway between the right olecranon and acromion process on the posterior of the brachium. The subject was positioned with the upper arm flexed at a 90-degree angle to the forearm. Using a tape measure, the distance was determined between the acromion and the inferior margin of the elbow along the side of the arm. The skinfold was picked up one centimeter above the mark and the measurement was taken on the midpoint. Medial calf measurements were taken with the right leg placed on a bench with the knee flexed at 90-degrees. The level of the greatest calf girth was marked on the medial border. A vertical skinfold was raised on the medial side of the right calf one centimeter above this mark, and the fold was measured at the maximal girth (Lohman, 1987). Percent body fat was determined from skinfolds employing computer software developed for children (Lohman & Lohman, 1987).
The children were instructed to complete an activity recall of the three most prevalent types of activities in which the child participates and the number of times involved in that activity per week. The children’s activity levels were assessed using a self-reported activity questionnaire (SRA) similar to McMurray et al., 1993. The SRA consisted of 34 different activities commonly associated with children, ranging in intensity from reading and video games to running, swimming, and soccer. If an activity was not listed, the child was encouraged to add it to their list. The intensities of the activities were coded, ranging from 0 to 8, using the Minnesota Leisure Time Physical Activity Questionnaire (Taylor, Jacobs, Schucker, Knudsen, Leon, & Debacker, 1978). An activity score was determined by multiplying the coded intensity, of each activity, by the number of times that activity was performed each week. The three scores were added together to obtain the total SRA value for each child. Activity intensities were separated into four levels according to intensity range: non-physical/leisure (0 to 2), low (3), moderate (4 to 5), and high (6 to 8).
Data from the various fitness assessments were gathered and analyzed. Means and standard deviation values were calculated for all descriptive subject characteristics. Correlation coefficients were used to determine the relationships between different descriptive subject characteristics. Independent t-tests were used to signify any differences between activity intensities.

Results

Mean and standard deviation scores of 11 descriptive subject characteristics were formulated for children, ages 6 to 11 (n=15), and youth ages 12 to 18 (n=36). The results are reported in Tables 1 and 2, respectively. Due to the small number of female children, ages 6 to 11, the remaining data were analyzed using only the male and female youth participants, ages 12 to 18.

Table 1. Mean and standard deviation scores for descriptive characteristics of subjects ages 6 to 11.

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Table 2. Mean and standard deviation scores for descriptive characteristics of subjects aged 12 to 18.

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Mean values for height, weight, and body mass index were very similar to scores reported in other studies with conventionally schooled youth (McMurray et al., 1993; Pierce et al., 1992; Taylor & Baranowski, 1991). Mean values for systolic and diastolic blood pressures were found to be below the “normal” value of 120/80 mmHg which expresses very low risk in terms of cardiovascular disease (Hoeger & Hoeger, 1994).
Approximately 16% of the youth males were in the average range (10-12%) for body fat. All but four males, however, were within the optimal range for health and fitness of 10-20% body fat. Thirty-five percent of female youth were categorized in the average range of 21-23% body fat, and 13 of the 17 females were within the optimal range of 15-25% body fat. Flexibility scores for male youths (n=19), ranged from 20 to 43 centimeters with a mean value of 29.26 cm. This mean score measured in the 60th percentile, according to reported percentile norms (Hastad & Lacy, 1989).  Female’s (n=17) mean flexibility score was below average values, in the 40th percentile, with a range from 21 cm to a maximum of 41 cm. Mean scores for hand grip dynamometer tests were similar to norms reported in the Lafayette instruction manual. Males right and left hand values (rt=37.26 kg, l=31.69 kg) were slightly above norms of 34.41 kg and 31.69 kg, right and left hand respectively. Female’s scores (rt=27.26 kg, l=25.53 kg) were also slightly above reported norm values (rt=25.79 kg, l=23.95 kg).

Table 3. Correlation coefficients of physical activity and cardiovascular endurance with descriptive characteristics.

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Aerobic capacity (VO₂ max), relative to body weight, ranged from 16.36 to 46.71 ml/kg/min, with a mean of 34.11 ±7.96, for males and 24.81 to 40.83 ml/kg/min, with a mean of 31.01±4.91, for females. Means for males and females ranged in the average fitness classification according to Hoeger and Hoeger (1994) for males and females £29 years of age. V0₂ max mean values, for females, exhibited several significant relationships. VO₂ max showed significant (p<.05) negative relationships with weight (r=-.54, p=.019); systolic blood pressure (r=-.45, p=.048), and percent body fat (r=-.56, p=.016) which was similar to findings reported by Al-Hazzaa, Sulaiman, Al-Matar, and Al-Mobaireek, 1994. In addition, VO₂ max showed significant (p<.01) associations with flexibility (r=-.66, p=.003) and body mass index (r=-.66, p=.004). Males exhibited three significant VO₂ max relationships with percent body fat (r=-.48, p=.036); systolic blood pressure (r=-.48, p=.036) and diastolic blood pressure (r=-.46, p=.043). Correlation coefficients for aerobic capacity and physical activity with various subject characteristics are reported in Table 3.
As stated previously, physical activities were coded and separated into four categories relative to the intensities of: high, moderate, low, and non-physical/leisure. Mean and standard deviation scores of physical activities and the most frequently performed activities are presented in Table 4. Independent t-tests determined a significant difference existed, t(21) = 2.50, p<.05, between male’s (M=6.36, sd=1.95) and female’s (M=3.88, sd=2.80) reported amount of high intensity activity per week.

High Intensity*            6.36+1.95         14            3.89+2.80         9
Moderate Intensity            4.46+2.96         13            5.56+2.88         9
Low Intensity            5.00+2.83         5            4.38+3.29         8
Non-Physical/Leisure            5.50+1.29         4            8.88+5.74         8

* t-tests, p<.05

        Top Five Activities Reported               
Boys (n=19)                  Girls (n=17)
riding a bicycle              walking
basketball                                 gymnastics
soccer                          swimming
volleyball                                   dancing
softball                          playing an instrument

Discussion

Analysis of the data collected for this study indicated that the home schooled participants showed similar findings in physical fitness variables to values of reported average data. Anthropometric measurements, such as percent body fat, showed that the majority of both males and females ranked in their respective optimal body fat ranges, but much smaller percentages (male-16%, female-35%) were classified in the average range. Hamstring flexibility ranged slightly above average (50th percentile) for males and slightly below for females. These values tend to contradict the idea that females are generally more flexible than males. Hand grip dynamometer tests, for males and females, related closely with reported norms for similarly aged individuals, with males displaying greater mean strength values for both right and left hands.
Male and female SRA scores were well below scores reported by McMurray et al. (1993) which involves younger children. Individuals in this study with a higher mean age for the males and females would seem to support the declining fitness of children and youth. Pierce et al. (1992) reported that fitness levels of persons entering college are not encouraging and activity patterns may be reflecting inappropriate activity choices. Kuntzleman (1993) reported that youth in the United States are not participating in physical activity sufficient for cardiovascular endurance and are therefore at risk for development of diseases associated with sedentary lifestyles.
The results of this investigation demonstrate that the physical fitness and activity characteristics of the home schooled children in this investigation were comparable to average reported values which are derived primarily from conventionally schooled children. Even though the scores are similar, there is a question as to whether all home schooled children’s fitness and activity levels are similar to these participants since they were a self-selected sample. The home schooled children in this study, however, were minimally, if at all, different from results established from studies utilizing conventionally schooled youth. It is recommended that the parents of home schooled children require participation in regularly scheduled physical activity and provide education to their children concerning health, physical fitness, and wellness.
Even though home school children had fitness characteristics which were similar to those of children in public schools, they were not physically active. This could be due to several factors: (1) few outside influences like physical education teachers, coaches, and other active peers; (2) no time during the home school day designated specifically for physical education or physical activity; (3) physical fitness having a lower priority than academics (Meadows et al., 1992); and (4) home school parents not knowing how to provide the physical activity needed by their children. The results of this investigation led to the conclusion that even though these home schooled children do not participate in school-mandated physical education courses, their physical fitness and activity profiles were minimally, if at all, different from results established from studies utilizing conventionally schooled youth. This research supports the development of a strong wellness education program in the home school environment with emphasis on positive attitudes toward physical fitness, especially in girls who eventually become mothers and influence their children’s fitness behaviors. These findings also indicate the need to educate home schoolers about ways to provide physical activities for their children either at home by themselves or with others in support groups. This could be accomplished in part by targeting publishers of home school curriculum and materials in an effort to provide home schoolers with information concerning fitness and activities that parents can do with their children to get fit and stay fit.

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