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In this study, running economy differences between boys and men at a common speed (ABS - 9.6 kph) and at a relative speed adjusted for body size (REL = 3.71 leg lengths per second) were examined. The caloric cost relative to mass was significantly higher for the boys for ABS (men = .17, boys = .20), but not for REL (both .19), The relative heart rate (%HRmax) and ventilatory equivalent were higher for the boys at ABS, but not at REL. Boys had significantly higher stride frequencies in both conditions. Stride length/leg length was greater for boys during ABS, and for men during REL. Respiratory exchange ratios (RERs) were not different at ABS (men = .94, boys = .96), but during REL, boys had a significantly lower RER (.93 vs. .98). Running economy differences between adults and children are reduced when speeds are adjusted relative to body size. This model may be useful for identifying developmentally based differences in the physiology and biomechanics associated with exercise. [ABSTRACT FROM AUTHOR]

This study examined the validity and reliability of the Rating of Perceived Exertion (RPE) scale and the Children's Effort Rating Table (CERT) as methods of regulating exercise intensity during discontinuous cycle ergometry. Sixty-four school children (ages 9-10) were randomly assigned to one of two groups, RPE or CERT, and received two trials 7 days apart. On both occasions, subjects produced 4 X 4-min scale-specific exercise intensities—3,5,7, and 9 (CERT) or 8, 12, 15, and 18 (RPE)—interspersed with 2-min rest periods. Analyses yielded significant (p<.01) correlations between perceived effort levels and objective measures: r = .47 to .61 (heart rate) and r = .59 to .75 (power output). Intraclass correlations indicated satisfactory overall repeatability of the produced exercise intensities (R>.70), but some notable inconsistencies were observed. The usefulness of effort perception scales among preadolescent children is presently rather limited, probably due to a number of confounding factors that need to be systematically addressed. [ABSTRACT FROM AUTHOR]

The article presents support for a scientific rationale supporting the value of exercise for the cardiovascular health of children. The article discusses definitions of cardiovascular health and exercise, risk factors associated with coronary artery disease, how exercise influences cardiovascular health, and examples of various medical studies researching cardiovascular health. According to the article, while many studies have failed to show exercise to have a beneficial effect on risk factors for coronary artery disease, flaws in many of the studies may account for some of the null results. Children develop habits, attitudes, and physiologic characteristics that have a long-term impact on future behaviors and qualities.

Maximal lactate steady state (MLSS) corresponds to the prolonged constant workload whereby the kinetics of blood lactate concentration clearly increases from steady state. Different results of MLSS in children may reflect specific test protocols or definitions. Three methods corresponding to lactate time courses during 20 min (MLSS 1), 16 min (MLSS II), and 8 min (MLSS III) of constant submaximal workload were intraindividually compared in 10 boys. At MLSS I, lactate, VO2 peak, heart rate, and workload were higher (p<.05) than at MLSS II and at MLSS III. The differences between MLSS I, MLSS II, and MLSS III reflect insufficient contribution to lactate kinetics by testing procedures, strongly depending on the lactate time courses during the initial 10 min of constant workload. Previously published divergent results of MLSS in children seem to reflect a methodological effect more than a metabolic change. [ABSTRACT FROM AUTHOR]

The article presents an argument stating that there is not a scientific rationale supporting the value of exercise for the cardiovascular health of children. According to the article, there is no convincing evidence available that either improving physical activity or increasing fitness in normal healthy, nonobese children will alter risk factors for adult coronary artery disease. While there are reasons to suppose that regular exercise habits will prevent the development of risk factors in healthy individuals over time, there is no scientific basis to assume that is true. The article discusses a rationale suggested by S. N. Blair and colleagues.

The purpose of this study was to examine the relationships between physical activity and physical fitness and adiposity in a sample of 77 girls, aged 10-11years. Physical activity was assessed by 7-day physical activity recall by which children reported how much time they spent on low and moderate-to-vigorous physical activities. Physical fitness was measured by EUROFIT test battery. Adiposity was estimated by sum of five skinfolds. The main finding of the study was that moderate-to-vigorous physical activity and adiposity were significant predictors (with 16-34% accounted variance) of physical fitness tests where the body mass affects performance. Indicators of physical activity and adiposity were not significantly related with fitness items requiring muscular strength, balance, flexibility, and speed of limb movement. Furthermore, moderate-to-vigorous physical activity and aerobic fitness predicted 22% of variance in adiposity in girls [ABSTRACT FROM AUTHOR]

Physiological and perceptual responses at ventilatory threshold (VT) and VO2peak were examined in 10 male children (10.2 ± 1.3 yrs) during graded treadmill and cycle exercise. Treadmill VO2 peak (57.9 ± 6.7 ml · kg-1 · min-1) was higher (p &It; .05) than the cycle (51.7 ± 7.7 ml · kg-1 · min-1). Ventilation and heart rate (HR) were higher (p &It; .05) on the treadmill, while respiratory exchange ratio (RER), rating of perceived exertion (RPE), capillary blood lactate, and test duration were similar between tests. The VO2 at VT was higher (p &It; .05) on the treadmill (36.7 ± 4.6 ml · kg-1 · min-1) than the cycle (32.5 ± 4.4 ml · kg-1 · min-1). When VT was expressed as a percentage of VO2 peak, there was no difference (p > .05) between tests. The RPE at VT, HR at VT, and VT expressed as a percentage of HR peak were also similar (p > .05) between tests. Similar to VO2 peak, the VO2 at VT is dependent on the mode of exercise. However, when VT is expressed as a percentage of VO2 peak, it is independent of testing modality. The RPE at VT appears to be linked to a percentage of VO2 peak rather than an absolute VO2. [ABSTRACT FROM AUTHOR]

Indoor play for pay centers (PPCs) have become very popular over the last decade. Due to the group format and physical design, the PPC promotes fast-paced large muscle activity that appears to increase the heart rate of prepubescent participants. The purpose of this study was to measure children's heart rate response to self-directed play at a PPC. Fourteen boys and girls (age = 7.8 ± 1.8 years) participated in a treadmill test to determine their maximal heart rate (MHR). On a separate day these same children played freely for 20 min over a 5,000 square foot multilevel PPC while their heart rate was monitored. The average MHR obtained in the laboratory was 204 ± 1.3 bpm, while the average heart rate during free play was 158 ± 38.5 or 77% of the MHR observed in the laboratory. These results suggest that the PPC promotes an increase in heart rate among self-directed prepubescent subjects. [ABSTRACT FROM AUTHOR]

A cross-sectional design was used to study the associations among sex, age, maximal aerobic speed (MAS), and running time to exhaustion at 100% of MAS (Tlim ). The subjects were 1,448 schoolchildren (685 males and 763 females) ages 6 to 17 years. The MAS of males increased significantly (p &It; .001) from 6 (9.0 ± 0.8 km · h-1) to 17 years (14.1 ± 1.6 km · h-1). The MAS of females increased significantly (p &It; .001) from 6 (8.7 ± 0.6 km · h-1) to 12 years (10.7 ± 1.2 km · h-1), then remained relatively constant at approximately 11 km · h-1 between 12 and 17 years. Tlim increased significantly from 6 to 13 years for males and from 6 to 11 years for females, then remained relatively constant around 350 s for both males and females. [ABSTRACT FROM AUTHOR]

Physical educators have purported to teach children to be physically active and to promote their fitness. To achieve these goals, children should regularly experience moderate-to-vigorous physical activity (MVPA) during physical education lessons. For the purposes of this review, moderate physical activity is that which elicits a heart rale of 50% of maximum heart rate reserve (MHRR), moderate-to-vigorous activity elicits 60% of MHRR, and vigorous activity elicits 75% of MHRR. Duration criteria were set at 50% of lesson time or 20 min. The majority of lessons described in previous reports failed to achieve these criteria, although problems were noted in method and analyses of data. Lessons with physical activity as a direct goal have been successful in increasing MVPA. A greater focus on physical activity is required in the planning and delivery of physical education lessons if the physical activity and fitness goals of the physical education curriculum are to be met. [ABSTRACT FROM AUTHOR]

The purpose of this article is to clarify the scientific basis of physical fitness assessment in children and to review the European efforts to develop a EUROFIT fitness test battery for the youth in the countries of the Council of Europe. The development of EUROFIT is based on the efforts made in the United States in the 1950s and in Europe in the 198Os. Physical fitness measurement is not identical to physiological measurement: The EUROFIT tests are aimed at measuring abilities rather than skills. Correlations between physical fitness tests and physiological laboratory tests show varying results and, therefore, need to be continued. Reliability of fitness tests needs to be continually studied. Because of the multipurposes of physical fitness testing, EUROFIT norm- and criterion-referenced scales for EUROFIT have to be developed. Examples of scaling methods are given. Implementation of the EUROFIT fitness tests for educational purposes is urgently needed. [ABSTRACT FROM AUTHOR]

The article looks at alternative means of exercise testing for children. According to doctor Dan Cooper, one should be wary of the concept of routine testing of children. The article discusses how to test for myocardial ischemia in a patient with aortic stenosis and how to test for exercise-induced bronchospasm in a child with shortness of breath with exercise. The article states that you can use dynamic changes in physiological relationships during submaximal exercise to assess cardiopulmonary function. Alterations in the recognized changes in immune function with acute exercise might be utilized to study patients with abnormalities of body defense mechanisms.

This study assessed and compared the validity of children's effort ratings using the established Borg 6-20 Rating of Perceived Exertion (RPE) scale and a recently devised Children's Effort Rating Table (CERT) during continuous cycle ergometry. Seventy school children were randomly assigned to one of two groups: Group 1 (RPE) and Group 2 (CERT). Both groups received two incremental exercise trials (Trial 1 and Trial 2) 7 days apart. For both scales, data analysis yielded significant (p<.01) Pearson correlations between perceived effort ratings and heart rate (HR) (rs≥.50) and perceived effort and absolute power outputs (rs≥.59). Moreover, correlations for CERT were consistently higher than for RPE. Test-retest intraclass correlations of R = .91 (CERT) and R = .90 (RPE) revealed that both scales were reliable. These data suggest that among preadolescent children the traditional scale (RPE) is not the only, nor indeed the best, option for monitoring perceived exertion during controlled exercise. [ABSTRACT FROM AUTHOR]

Little information is available on the safety of supervised exercise programs for children. This retrospective case review describes the experience over 5 years in a private, outpatient, physician-directed therapeutic exercise program. Observations were made on a total of 47 patients referred by their physicians or parents for exercise programs for diseases, including obesity (26), cystic fibrosis (10), cardiac disease (3), asthma (3), and others (5). Patients performed circuit training with an exposure that consisted of 2,646 total sessions (56.3 ± 63.3 sessions/patient), equivalent to 1,507.9 hours (32.1± 35.5 hr/patient) of exercise time. There were three minor accidents (1.9/1,000 patient hours). Physical examination by the attending physician was negative in all three cases: No treatment was indicated, and no patient missed any training time due to these incidents. No significant injuries or cardiorespiratory complications were observed in this exercise program. [ABSTRACT FROM AUTHOR]

Nonobese, preadolescent girls self-reported, and their parents provided proxy reports of daughters' daily activities using questionnaires. Responses were evaluated for test-retest reliability, and for validity using one-week diaries. Results indicated all three respondents provided reproducible estimates of time daughters spent watching TV; daughters and mothers, of time daughters spent sleeping; and parents, of time daughters spent in vigorous activities. However, only daughters >10 years of age could provide valid reports for time spent in moderate activities and in sedentary and light activities on school days. Study results suggest that daughters and parents have difficulty providing reliable and valid estimates of activity level. [ABSTRACT FROM AUTHOR]

The article presents a response to the editorial "The Horse Is Dead; Let's Dismount," by T. W. Rowland in the May 1995 issue. The examines how to encourage children to be physically active daily and to continue their physical activity throughout their lifetime. The article also discusses physical fitness testing, getting children to participate in enjoyable physical activities, the negative affects of forcing high-intensity activities on children, and the negative affects of making high-level performance the primary focus of youth sports.

The article present several abstracts from various pediatric medical journals. One study, by M. E. M. Jenney and colleagues, looked at the long-term effects of chemotherapy and radiation therapy used to treat childhood leukemia and cardiopulmonary fitness in those survivors. Another study, by B. Glenmark and colleagues, looked at predictors of adult physical activity during adolescence. Other studies researched the relationship of physical activity and body fat in children, the prevalence of coronary risk factors in adolescents, and physiological aspects of high school football players.

The article looks at the 1995 annual meeting of the American College of Sports Medicine (ACSM) and presents 10 ACSM pediatric research literature abstracts. Medical research by Dan Cooper and colleagues suggests that daily physical activities of children are not random, but rather exhibit a certain periodicity. A study by B. T. Plunkett and W. G. Hopkins looked at the cause and treatment of side pain in runners. Other studies looked at the maternal influence on bone density of prepubescent female gymnasts and ventilatory and lactate thresholds in children.

The article presents abstracts from the annual meeting of the North American Society for Pediatric Exercise Medicine held in Pittsburgh, Pennsylvania on August 11-14, 1994. Robert R. Wolfe and colleagues researched the exercise performance in children with congenital valvular aortic stenosis. Laura L. Kraft and colleagues studied the psychosocial benefit of participation in a pediatric cardiac rehabilitation program. Other medical studies researched syncope in children, cardiorespiratory responses in teenage girls with chronic fatigue, and aerobic capacity in African American girls.

This study examined habituation to treadmill walking or running in children. Twenty-four boys and girls, ages 7-11, completed six 6-min trials of treadmill exercise at one of these speeds: (a) comfortable walking pace (CWP), (b) CWP + 15%, (c) running at CWP + 3 km·hr-1 or (d) running as above + 15%. The six trials were repeated in a second visit. The a priori criterion for habituation was a decrease in steady state values of oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio (RER), and stride rate (SR) or an increase in stride length (SL) and hip joint vertical amplitude (HA) from one trial to the next. There was no consistent pattern indicating habituation for the group. Many trials and more than one day of testing do not appear to improve the stability of the metabolic or kinematic variables. The lack of consistency in individual responses suggests that monitoring subjects' habituation individually is important. [ABSTRACT FROM AUTHOR]

The article looks at the advantages of basketball, both as a lifetime fitness activity and as a potential tool for the health-related physical activity movement. According to classical energy expenditure tables, basketball is a relatively high-energy consumption activity. Basketball stimulates aerobic endurance, muscular strength, and muscular endurance through running and jumping. Upper extremity muscles are involved through passing, shooting, and dribbling. The article discusses basketball instruction, basketball for children, the disadvantages of running, basketball equipment and supplies, and recommendations for future research.

The article looks at the article "Toward an Understanding of Appropriate Physical Activity Levels for Youth," by Charles Corbin, Robert Pangrazi, and Greg Welk, which was published in the November 1994 issue of "Physical Activity and Fitness Research Digest." In the article, Corbin and colleagues describe a strategy for reducing health risks through a lifestyle of regular physical activity rather than by the traditional approach of improving cardiovascular fitness with a scheduled exercise program. The article also discusses exercise tests for children.

The article presents abstracts from the annual meeting of the North American Society for Pediatric Exercise Medicine held in Pittsburgh, Pennsylvania on August 11-14, 1994. R. Peter Schnorr and Paul E. Nowacki researched the relationship of body composition to physical fitness and cardiovascular response of children. L. Ambrosetti and W. A. Saltarelli examined the physiological response of obese versus nonobese children playing action pad video games. Other studies looked at metabolic responses in male children and adults during exercise and impaired neutrophil function following exercise in gymnasts.

The purpose of this investigation was to compare isometric test procedures (make vs. break tests by muscle groups) with elementary school girls, ages 9-11, using hand-held dynamometry. Fifty subjects in Grades 3 and 4 performed three trials on four muscle groups using each testing procedure following a preliminary session to allow familiarity with the instrumentation, test procedures, and test positions. Retest measurements were taken in 5-7 days with the order of the test procedures counterbalanced. Four 2 x 2 (Side x Test Condition) ANOVAs, with repeated measures on each factor, were used to analyze the data. Significant Side x Test Condition interaction effects were evident for knee extension, elbow flexion, and shoulder abduction. Except for the knee extension, the break test produced higher values than the make test in all muscle groups, which is in agreement with previous investigations. [ABSTRACT FROM AUTHOR]

Absolute total body (TB) and regional spine (RS) bone mineral content (BMC) measured by dual photon absorptiometry were lower (p < .05) in Turner syndrome (TS) girls compared to a cohort of younger (by 2 years) but taller and heavier prepubertal girls. Maximal voluntary strength (MVC) of the elbow flexors, knee extensors, and plantar flexors were also consistently and, in most cases, significantly lower in TS girls. Differences between groups in absolute bone mineral and muscle strength disappeared, however, when normalized for skeletal cross-sectional area (areal density) and for the product of muscle cross-sectional area and estimated moment arm, respectively. Maximal voluntary strength and body mass correlated moderately strongly with the bone mineral measures, but only body mass contributed significantly to the variance in total body and regional spine bone mineral measures. Bone mineral and muscle strength appear appropriate for body size and for skeletal and muscle morphology in young TS girls. [ABSTRACT FROM AUTHOR]

This study was designed lo determine the differing cardiorespiratory responses between maximal treadmill (TM) and cycle (CY) ergometry, and the reliability and variability of these responses in 46 children 7 to 9 years old (23 boys and 23 girls). Two maximal TM and two maximal CY tests were administered, as well as a body composition assessment. The TM resulted in a 9.4%, 11.1%, and 10.2% higher maximal oxygen consumption values (VO2, ml·kg-1·min-1) than the CY in boys, girls, and the total population, respectively. Both the TM and the CY proved to be reliable measures of maximal VO2 (ml·kg-1·min-1) in both boys and girls, with intraclass correlations ranging from R = .63 to .90. Variability was significantly less (p ≤ .05) on the CY (VO2 in L·min-1) than the TM. 4.4% versus 6.2%, respectively. [ABSTRACT FROM AUTHOR]

This study was designed to examine the reliability and variability of running economy in 7-, 8-, and 9-year-old boys and girls. Forty-two children (21 boys and 21 girls) participated in two submaximal treadmill tests to determine running economy at two absolute work rates (5 mph and 6 mph). Reliability and variability were determined for oxygen consumption (VO2), heart rate (HR), respiratory exchange ratio (RER), stride frequency, and stride length. With the exception of RER and VO2 relative to body surface area, reliability estimates were moderate to high (.80 to .94). Mean variability of all responses were similar to those reported for adults, however, the range of intraindividual variability was slightly greater. These results indicate that two submaximal measurements result in higher reliability estimates than a single test and may therefore provide a more appropriate description of a child's running economy. [ABSTRACT FROM AUTHOR]

This study was designed to determine the validity and reliability of the 9-min distance run in assessing cardiorespiratory fitness in third-grade children. Fifty-one children (27 girls and 24 boys) participated in at least one maximal cycle ergometer test to determine peak oxygen consumption (VO2peak) and in two 9-min runs. Significant (p <<.01) test-retest intraclass correlations indicated that both the peak cycle ergometer test and the 9-min run were reliable measures in boys and girls and when the total sample was combined. Interclass correlations of r = .62 and r = .64 were attained between VO2peak (ml·kg-1min-1) and 9-min Run 1 and 9-min Run 2, respectively. When data were separated by gender, 9-min Run 1 and 9-min Run 2 correlated to VO2peak (r = .56 and r = .48 for the girls and r = .65 and r = .71 for the boys, respectively). These results suggest that the 9-min distance run is a reasonably valid and highly reliable field test for estimating cardiorespiratory fitness in third-grade children. [ABSTRACT FROM AUTHOR]

The effects of exercise training on hemodynamics and on the prevalence of arrhythmias in 11 asymptomatic children following tetralogy of Fallot (TOF) repair were investigated. Training consisted of three 30-min supervised exercise sessions per week for 8 consecutive weeks. Each subject exercised on a cycle ergometer and/or treadmill at 60-80% of measured peak heart rate (HR). Submaximal HR decreased (p < .0016), and maximal treadmill time increased, in every patient (p < .0004). Small decreases occurred in submaximal cardiac output (CO) (p < .094), VO2 (p < .047), and respiratory rate (RR) (p < .053). No significant change occurred in peak HR, peak VO2, or in resting LV end-diastolic dimension or posterior wall thickness. No significant change occurred in atrial or ventricular ectopy. It was concluded that young active children following repair of TOF can demonstrate aerobic training effects with an 8-week exercise program of three 30-minute sessions of moderately intense aerobic activity per week. [ABSTRACT FROM AUTHOR]

To date, very little published information has been available on the physical activity participation of disabled youth. A questionnaire, which was modified from the Canada Fitness Survey, was distributed by mail to physically disabled, sensory impaired, and chronically ill children and adolescents in Ontario, Canada. Nine hundred eighty-seven responses were collected from subjects 6 to 20 years of age, with a response rate of 58%. Twenty-nine percent of physically challenged youth were found to be sedentary, and 39% were active. Activity levels were significantly related to age (p < .01), with a marked decline in the second decade of life. Activity levels were not significantly influenced by gender, but the data suggest that girls have lower activity levels and a faster and earlier decline in activity than boys. Overall, the data collected provide baseline information on the role of physical activity in the lives of Ontario youth with physical disabilities, sensory impairments, and chronic illnesses. [ABSTRACT FROM AUTHOR]

This study examined the relationship between dispositional achievement goal orientations and intrinsic motivation following physical fitness testing. Students, aged 11-15 years, completed the Task and Ego Orientation in Sport Questionnaire, participated in the 20-m progressive shuttle run test, and then completed a modified Intrinsic Motivation Inventory (IMl). Using their goal orientations, students were placed into one of four groups: low in both task and ego. high ego/low task, high task/low ego. and high in both task and ego. A MANOVA indicated that for students in the "high" and "low" performance groups, differences in intrinsic motivation between goal orientation groups were found. Perceived success and goal orientations had independent effects on intrinsic motivation for the lower performance group but interacted to influence intrinsic motivation for the higher performance group. It is concluded that children have different motivational reactions to fitness testing, depending on their goal profile, performance, and perceived success. [ABSTRACT FROM AUTHOR]

A 3-year controlled intervention was used to study the influence of physical activity on the plasma lipid and apoprotein profile of 10-year-old Dutch schoolchildren. Twice-a-year measurements were taken of height, weight, body composition (skinfolds), pubertal development (Tanner stages), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), triglycerides(TG), apoproteins A-I and B (immunoturbidimetry), and participation in physical activities. The effect of the intervention was analyzed with a MANOVA. The intervention did not affect the level of the lipids and apoproteins of the boys. In the girls, the intervention led to a smaller increase of TG and a larger decrease of apoprotein A-I. There may be two explanations for the limited intervention effect. First, it may be due to the healthy baseline plasma lipid and apoprotein profile, which leaves little room for improvement. Second, the exercise intensity during the physical education classes may have been too low to bring about the desired effect. [ABSTRACT FROM AUTHOR]

Maximal oxygen uptake (VO2max), submaximal grade-walking oxygen uptake, and anthropometric measures were measured in a group of 19 children in 1988 and in 1992, The children were 5.2 ± .9 years old in 1988 and 9.2 ± 1.0 in 1992. The VO2max did not change relative to body weight over the 4 years (44.6 ml·kg-1min-1 in 1988 versus 43.3 ml·kg-1min-1 in 1992). Lower specific weight-relative oxygen uptakes were seen at the submaximal work levels in 1992 than in 1988, indicating an improvement in grade-walking economy. [ABSTRACT FROM AUTHOR]

The doubly labeled water technique represents an unobtrusive and noninvasive means to measure total daily energy expenditure in free-living human subjects who are unaware that energy expenditure is being measured. When combined with measurement of resting energy expenditure, the doubly labeled water technique can also be used to estimate energy expenditure related to physical activity. The relatively recent availability of the doubly labeled water technique in humans has led to several advances in the fundamental understanding of whole body energy metabolism in several important areas. The purpose of this paper is to review the areas in which the doubly labeled water technique has specifically advanced our understanding of whole-body energy metabolism in young children. [ABSTRACT FROM AUTHOR]

The article presents abstracts of studies from various sports medicine and pediatric journals. J. F. Sallis and colleagues researched the validity of children's self-reports of their physical activity. T. N. Robinson and colleagues examined the association between obesity, television viewing, and physical activity. Other studies looked at the Wingate anaerobic test, the ventilatory threshold, the atherosclerotic process, a nuclear magnetic resonance spectroscopy of exercising muscles, and hormonal changes in runners with menstrual dysfunction.

This study assessed serum ferritin, hemoglobin, and hematocrit among 107 physically active young people 9 to 18 years of age. Tanner stage (TS) of puberty was assessed and subjects were categorized as prepubertal (TS 1), midpubertal (TS 2, 3, and 4, excluding menarcheal females) and going through their rapid growth phase, or late pubertal (TS 5 and menarcheal females) and having completed their rapid growth phase. Midpubertal females had a lower hematocrit than late pubertal females, but there were no significant differences in serum ferritin or hemoglobin between pubertal groups. Late pubertal males had hemoglobin and hematocrit values that were higher than among prepubertal males, but serum ferritin did not differ. At late puberty the males had significantly higher serum ferritin, hemoglobin, and hematocrit compared with late pubertal females, and females in late puberty were more likely to have marginal iron stores compared with males at the same stage of pubertal development. Midpubertal and late pubertal females reported a diet low in absorbed iron, which could contribute to their poorer iron status. [ABSTRACT FROM AUTHOR]

The present study examined the relationship between maximal oxygen uptake (VO2max) and daily physical activity in a group of 7- to 12-year-old boys. VO2max was assessed through the incremental treadmill test using an open circuit system. Physical activity level was obtained from heart rate telemetry outside of school time for 8 hrs during weekdays and during 40 min of physical education classes. The findings indicated that the absolute value of VO2max increased with age, while relative to body weight it remained almost the same across age, with a mean of 48.4 ml · kg-1 · min-1. Moreover, heart rate telemetry showed that the boys spent a limited amount of time on activities that raise the heart rate to a level above 160 bpm (an average of 1.9%). In addition, VO2max was found to be significantly related to the percentage of time spent at activity levels at or above a heart rate of 140 bpm, but not with activity levels at or above a heart rate of 160 bpm. [ABSTRACT FROM AUTHOR]

The effectiveness of a twice-a-week strength training program on children was evaluated in 14 boys and girls (mean age 10.8 yrs) who participated in a biweekly training program for 8 weeks. Each subject performed three sets of 10 to 15 repetitions on five exercises with intensities ranging between 50 and 100% of a given 10-repetition maximum (RM). All subjects were pre-and posttested on the following measures: 10-RM strength, sit and reach flexibility, vertical jump, seated ball put, resting blood pressure, and body composition parameters. The subjects were compared to a similar group of boys and girls (n = 9; mean age 9.9 yrs) who were randomly selected to serve as controls. Following the training period, the experimental group made greater gains in strength (74.3%) as compared to the control group (13.0%) (p < 0.001), and differences in the sum of seven skinfolds were noted (-2.3% vs. + 1.7%, respectively, p < 0.05). Training did not significantly affect other variables. These results suggest that participation in a short-term, twice-a-week strength training program can increase the strength and improve the body composition of young boys and girls. [ABSTRACT FROM AUTHOR]

This study examined the interrelationships between young athletes' and parents' personal and perceived goal orientations in sport. Forty-three boys and 34 girls who were involved in a summer basketball camp completed the Task and Ego Orientation in Sport Questionnaire (TEOSQ) with respect to their own dispositional goal perspective in basketball and their perceptions of the goal orientation of the parent who was most involved with their basketball participation. The parents (55 mothers and 21 fathers) responded to the TEOSQ in terms of their personal goal orientation and their perceptions of the goal orientation held by their child in basketball. Results revealed no significant correlations between children's and parents' self-reported task and ego orientation. Children's goal orientation was significantly related to their views concerning the goal orientation adopted by their parents. The implications of these findings for understanding the socialization of sport goal orientations are discussed. [ABSTRACT FROM AUTHOR]

Identifying social and psychological influences affecting children's attitudes about physical activity is an important step in understanding individual differences in children's activity involvement. This study examined the influence of parental socialization and children's psychological characteristics upon attraction to physical activity. Fourth-grade children (N=81) completed questionnaires assessing perceived physical competence and attraction to physical activity. Parents also completed questionnaires assessing their physical activity orientations and level of encouragement of their child's physical activity. A proposed model linking four sets of social and psychological variables was tested through path analysis. The results generally supported the hypothesized model and suggested that parental physical activity orientations, parental encouragement levels, children's gender, and children's perceived physical competence are important influences upon children's attraction to physical activity. [ABSTRACT FROM AUTHOR]

The article looks at children's enjoyment of and attitude toward physical activity. The article discusses children's motivation for physical activity, health behavior in children, psychological stress in sports, physical fitness testing for children, exercise for children, and pediatric sport psychology literature. According to the article, social support, skill level, self-perception, and positive affect all contribute to children's motivation to start and continue in sports and other physical activities.

The purpose of this study was to determine the anaerobic capacity of children using the maximal accumulated oxygen deficit technique (AOD). Eighteen healthy children (9 boys, 9 girls) with a mean age of 10.6 years volunteered as subjects. Peak oxygen uptake and submaximal steady-state oxygen uptake tests were conducted against progressive constant work rates on a Cybex cycle ergometer. Supramaximal work rates were predicted from the linear regression of submaximal steady-state work rates and oxygen uptakes to equal 110, 130, and 150% of peak oxygen uptake. Results indicated a significant interaction in the responses of both sexes when the accumulated oxygen deficit data were expressed in both absolute and relative terms. The profile of accumulated oxygen deficits across the three intensities indicated a downward shift in the girls' responses between the 110 and 150% supramaximal tests. This trend was not evident in the boys' responses. Intraclass correlations conducted on test-retest data indicated that compared to the boys, the reliability of the girls in the accumulated oxygen deficits in liters and ml·kg-1 was poorer. [ABSTRACT FROM AUTHOR]

This study examined the validity of the Caltrac motion sensor for measuring physical activity in young children and described change over time in physical activity among 47 preschool children from obese and nonobese families. Children were videotaped in a controlled setting while wearing Caltrac motion sensors and also wore Caltracs at home. Caltrac readings and an observational measure of physical activity were significantly related in both Year 1 (r =.86) and Year 2 (r =.83), and outside play was associated with higher Caltrac scores (r =.43). In addition, physical activity among young girls with obese parents decreased significantly from Year 1 to Year 2. [ABSTRACT FROM AUTHOR]

This study investigated the validity of the Caltrac accelerometer for estimating resting and exercise energy expenditure for children. Seventeen children 9 to 12 years of age participated in the study. Criterion values of energy expenditure were determined from measures of oxygen consumption (VO2) and respiratory exchange ratio (RER), and Caltrac estimates of energy expenditure were obtained concurrently for each experimental condition. Correlations were significant between Caltrac estimates and measured energy expenditure at rest (r = .53, p<.03) and at slow (r = .89, p<.001) and brisk (r = .85, p<.001) treadmill walking. The Caltrac overestimated caloric expenditure for rest (M = 7%; range = - 8 to 36%) and also for both slow (M = 17%; range = - 3 to 30%) and brisk (M = 25%; range = 5 to 46%) walking. However, because of the high validity coefficients during activity, and because of its practicality in field settings, the Caltrac may be useful in estimating daily resting and walking energy expenditure for groups of children. [ABSTRACT FROM AUTHOR]

Models to indirectly estimate minute ventilation (VE) from heart rate (HR) monitored during normal activity were developed. VE-to-HR relationships were established from VE and HR measured in a graded cycle ergometer test performed by 99 girls, 7-14 years of age. The regression In VE = a + (b X HR) was a better predictor of VE, when individually determined, than were generalized prediction equations. VE, estimated by applying individual VE-to-HR regressions to HR monitored over 10 daytime hours, ranged between 11.5 and 14.5 L·min-1. This is a practical method of estimating VE, but further validation of the relationships with HR under various modes of exercise are necessary to improve the prediction in everyday settings. [ABSTRACT FROM AUTHOR]

Monitoring of physical activity among 3- to 7-year-old children was achieved with an electronic motion sensor, the Caltrac accelerometer, for 1,666 days (of 2,030 scheduled) over a 2-year period. Failure of the monitor averaged once for each 45 days of successful monitoring. The total cost of devices, repairs, and batteries over the 2 years averaged $1.31 per day of successful monitoring. It is concluded that use of the Caltrac accelerometer is a feasible and relatively inexpensive approach for monitoring physical activity in young children in epidemiologic studies. [ABSTRACT FROM AUTHOR]

The present study examined the relationships among the AAHPERD Physical Best health related physical fitness test (HRPFT) items to resting blood pressure in 80 boys and 84 girls from the Lanciano, Italy, school system. Systolic blood pressure (SBP) was significantly associated with age for both sexes. Diastolic blood pressure (DBP) for boys was found to be associated with fatness when age was held constant. To examine the relationship between blood pressure and the HRPFT, data were sorted into two groups of students passing or failing to meet the criterion-referenced standard (CRS) by 1-mile run performance and sum of skinfolds. SBP did not differ significantly between groups for either sex. Boys who failed to meet the CRS for 1-mile run performance showed a higher DBP of 4 mmHg when compared to boys who achieved the CRS. The group passing the aerobic fitness and body composition tests tended to perform better on all test items. With the possible exception of DBP for boys, it is concluded that performance on the Physical Best HRPFT is not associated with resting blood pressure in children and adolescents. [ABSTRACT FROM AUTHOR]

The article presents abstracts of various studies from different pediatric and sports medicine journals. P. S. Freedson and S. Evenson looked at the familial association between parents and their children's physical activity and health behavior. E. Esquivel and colleagues compared the effects of hyperpnea induced by physical exercise with those created by voluntary hyperventilation in children with absence epilepsy. Other studies researched exercise responses following tetralogy of Fallot surgery and exercise responses to treatment of anemia in patients with chronic renal disease.

Data for the analysis were the health related fitness scores, anthropometric measures, and physical activity information from the National Children and Youth Fitness Study. The subjects were 6,800 boys and 6,523 girls, ages 6 through 18. Multiple regression produced linear composites that were used as covariates to evaluate physical and environmental characteristics that relate to gender differences. The distance runs, chin-ups, and sit-ups displayed similar patterns in gender differences across age. Before puberty the important covariates are mainly physical, namely skinfolds. Following puberty the major factors that reduce gender differences are skinfolds and the amount of exercise done outside of school time. [ABSTRACT FROM AUTHOR]

This study examined the ability of 40 children (20 boys and 20 girls), ages 11 to 14 years, to regulate the intensity of their effort using perceived effort ratings during cycling. The Borg Rating of Perceived Exertion 6 to 20 Scale was learned and used as a perceptual frame of reference. Maximal oxygen uptake and power output were predicted from telemetered heart rate data collected during a submaximal graded exercise test. Subjects were then fully familiarized with the RPE scale and attended three consecutive sessions of cycling during which they adjusted the workloads themselves so as to produce effort intensities for scale ratings of 9 (very light), 13 (somewhat hard), and 17 (very hard). Heart rates were sampled during the final half minute of each session and the data were submitted to a mixed factorial analysis of variance. This showed highly significant differences (p<.001) between the three RPE levels but no significant effects for age, gender, or trials. It was concluded that the RPE is readily learned by older children and adolescents and is a potentially useful frame of reference when self-regulating effort intensity during vigorous exercise. [ABSTRACT FROM AUTHOR]