Deleterious effects of obesity on physical fitness in pre-pubertal children

The prevalence of obesity in children has increased dramatically during the past decades in Europe and understanding physical fitness and its components in children is critical to design and implement effective interventions. The objective of the present study was to analyse the association between physical fitness (aerobic, speed, agility, power, flexibility and balance) and body mass index (BMI) in pre-pubertal children. A total of 2411 healthy schoolchildren (7–11 years) participated in this study. Anthropometric characteristics and body composition were assessed by skinfold thickness. Physical fitness was measured by nine physical fitness tests: endurance running, 20 m running speed, agility, handgrip strength, standing long jump and squat jump, sit and reach, medicine ball forward throw and static balance. No relevant differences were observed between boys and girls regarding anthropometric characteristics, body composition and physical fitness. However, overweight and obese children showed significantly lower physical fitness levels in endurance running, speed and agility (mean: +18.8, +5.5 and +14.5% of time to complete tasks, respectively), lower limb power normalised to body mass (?23.3%) and balance tests (number of falls: +165.5%) than their normal weight counterparts. On the other hand, obesity did not affect handgrip, throwing and flexibility. In conclusion, increased BMI was associated with lower performance capabilities limiting proper motor skill development, which directly affects the ability of children to take on sports skills. Actions undertaken to promote children's wellness and fitness should be prioritised and introduced early in life with the aim of enhancing physical fitness as well as preventing overweight and obesity.     

Sex-specific associations of moderate and vigorous physical activity with physical fitness in adolescents

The present study examined the sex-specific associations of moderate and vigorous physical activity (VPA) with physical fitness in 300 Japanese adolescents aged 12–14 years. Participants were asked to wear an accelerometer to evaluate physical activity (PA) levels of various intensities (i.e. moderate PA (MPA), 3–5.9 metabolic equivalents (METs); VPA, ≥6 METs; moderate to vigorous PA (MVPA), ≥3 METs). Eight fitness items were assessed (grip strength, bent-leg sit-up, sit-and-reach, side step, 50?m sprint, standing long jump, handball throw, and distance running) as part of the Japanese standardised fitness test. A fitness composite score was calculated using Japanese fitness norms, and participants were categorised according to their score from category A (most fit) to category E (least fit), with participants in categories D and E defined as having low fitness. It was found that for boys, accumulating more than 80.7?min/day of MVPA may reduce the probability of low fitness (odds ratio (ORs) [95% confidence interval (CI)]?=?0.17 [0.06–0.47], p?=?.001). For girls, accumulating only 8.4?min of VPA could reduce the likelihood of exhibiting low fitness (ORs [95% CI]?=?0.23 [0.05–0.89], p?=?.032). These results reveal that there are sex-specific differences in the relationship between PA and physical fitness in adolescents, suggesting that sex-specific PA recommendation may be needed to improve physical fitness in adolescents.     

Associations of total sedentary time,screen time and non-screen sedentary time with adiposity and physical fitness in youth: the mediating effect of physical activity

The aims of the present study were: i) to examine the associations of total accelerometer-based sedentary time (ST) and specific-domain self-reported ST (i.e., screen-based, educational-based, social-based, and other-based ST) with adiposity and physical fitness in youth; and ii) to analyse the mediation effect of physical activity (PA) on associations.

This study was conducted with 415 children (9.1 ± 0.4 years) and 853 adolescents (13.6 ± 1.6 years) in Spain during 2011–2012. Total ST and PA were assessed by accelerometry. Leisure-time spent in twelve sedentary behaviours was self-reported. Adiposity and physical fitness was measured following the ALPHA battery for youth.

Total accelerometer-based ST was positively associated with global adiposity score in children, and negatively associated with global physical fitness score in children and adolescents; but relationships were not independent of PA. PA mediated all associations of accelerometer-based and self-reported ST with adiposity or physical fitness in children. Conversely, screen-, educational-, social-, and other-based ST were negatively related to physical fitness in adolescents, independently of PA.

These findings give an impetus to developing effective strategies for specifically promoting PA in children and for increasing PA while reducing ST in adolescents in order to produce improvements on adiposity and physical fitness.     

Recurrent pain and discomfort in relation to fitness and physical activity among young school children

Abstract

As an increase in pain symptoms among children has been shown in the last decades, the aim of this study was to describe perceptions of recurrent pain, measured physical fitness and levels of reported physical activity (PA) in children, and to investigate if any associations between PA, fitness and recurrent pain could be identified. A school-based study comprised 206 Swedish children 8–12 years old, 114 boys, 92 girls. A questionnaire with questions about perceived pain, self-reported PA and lifestyle factors was used. Health-related fitness was assessed by 11 physical tests. A physical index was calculated from these tests as a z score. High physical index indicated high fitness and low physical index indicated low fitness. ANOVA test, chi-square test and logistic regression analysis were used to compare active and inactive children. The prevalence of one pain location (head, abdomen or back) was 26%, two 11% and three 4% (n=206). Female gender, living in single-parent families, low PA and low subjective health were associated with reported recurrent pain. Children reporting high levels of PA had high physical index and reported low prevalence of pain symptoms. The physical index and level of self-reported PA decreased gradually the more pain locations. Physically active children had higher fitness levels and reported less pain symptoms than inactive peers. Coping with pain is an integral part of PA, and active children learn to cope with unpleasant body sensations which together with high fitness may reduce the perception of pain.     

Steps counts among middle school students vary with aerobic fitness level

The purpose of this study was to examine if steps/day taken by middle school students varied based on aerobic fitness classification. Middle school students (N = 223; 112 girls, 111 boys) were assigned to three aerobic fitness categories (HIGH, MOD, LOW) based on results of the FlTNESSGRAM PACER test. Four weekdays of pedometer monitoring determined activity levels (steps/day). Boys accumulated significantly more steps/day than girls, 11,589 +/- 3,270 and 10,232 +/- 2,517 steps/day, respectively; F(1,219) = 16.0, p < .001, eta2 = .055. There were no differences in steps/day between grades. HIGH fit participants accumulated significantly more steps/day, F(2, 217) = 12.2, p < .101, eta2 = .101, than moderately fit and low fit participants (approximately 1,491 and ; 2,867 steps/day, respectively). Middle school students who participated in sports in addition to physical education (PE) accumulated significantly more steps/day (approximately 980 steps/day) than those participating in PE only, F(1, 219) = 10.0, p < .01, eta2 = .044. Although the relationship between physical activity and aerobic fitness was moderate (0.35; p < .01), these data demonstrated significant differences in accumulated steps/day among youth of varying aerobic fitness levels. Whether improved fitness levels were the result of additional activity or the cause of it remains to be determined. Regardless, the fittest middle school students were also the most active and accumulated a significant amount of steps/day through organized extracurricular physical activities.     

Using social cognitive theory to predict physical activity and fitness in underserved middle school children

Few researchers have used social cognitive theory and environment-based constructs to predict physical activity (PA) and fitness in underserved middle-school children. Hence, we evaluated social cognitive variables and perceptions of the school environment to predict PA and fitness in middle school children (N = 506, ages 10-14 years). Using multiple regression analyses we accounted for 12% of the variance in PA and 13-21% of the variance in fitness. The best predictors of PA were barrier self-efficacy, classmate social support, and gender; whereas, only gender predicted fitness. The results affirmed the importance of barrier self-efficacy and gender differences. Our findings regarding classmate social support are some of the first to illuminate the importance of school-specific peers in promoting PA.     

Relationship between physical activity,physical fitness and multiple metabolic risk in youths from Muzambinho's study

Negative associations between physical activity (PA), physical fitness and multiple metabolic risk factors (MMRF) in youths from populations with low PA are reported. The persistence of this association in moderately-to highly active populations is not, however, well established. The aim of the present study was to investigate this association in a Brazilian city with high frequency of active youths. We assessed 122 subjects (9.9?±?1.3 years) from Muzambinho city. Body mass index, waist circumference, glycaemia, cholesterolaemia, systolic and diastolic blood pressures were measured. Maximal handgrip strength and one-mile walk/run test were used. Leisure time PA was assessed by interview. Poisson regression was used in the analysis. The model explained 11% of the total variance. Only relative muscular strength and one-mile walk/run were statistically significant (p?相似文献   

The effects of plyometric jump training on physical fitness attributes in basketball players: A meta-analysis

BackgroundThere is a growing body of experimental evidence examining the effects of plyometric jump training (PJT) on physical fitness attributes in basketball players; however, this evidence has not yet been comprehensively and systematically aggregated. Therefore, our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players, in comparison to a control condition.MethodsA systematic literature search was conducted in the databases PubMed, Web of Science, and Scopus, up to July 2020. Peer-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes (muscle power, i.e., jumping performance, linear sprint speed, change-of-direction speed, balance, and muscle strength) in basketball players, with no restrictions on their playing level, sex, or age. Hedge's g effect sizes (ES) were calculated for physical fitness variables. Using a random-effects model, potential sources of heterogeneity were selected, including subgroup analyses (age, sex, body mass, and height) and single training factor analysis (program duration, training frequency, and total number of training sessions). Computation of meta-regression was also performed.ResultsThirty-two studies were included, involving 818 total basketball players. Significant (p < 0.05) small-to-large effects of PJT were evident on vertical jump power (ES = 0.45), countermovement jump height with (ES = 1.24) and without arm swing (ES = 0.88), squat jump height (ES = 0.80), drop jump height (ES = 0.53), horizontal jump distance (ES = 0.65), linear sprint time across distances ≤10 m (ES = 1.67) and >10 m (ES = 0.92), change-of-direction performance time across distances ≤40 m (ES = 1.15) and >40 m (ES = 1.02), dynamic (ES = 1.16) and static balance (ES = 1.48), and maximal strength (ES = 0.57). The meta-regression revealed that training duration, training frequency, and total number of sessions completed did not predict the effects of PJT on physical fitness attributes. Subgroup analysis indicated greater improvements in older compared to younger players in horizontal jump distance (>17.15 years, ES = 2.11; ≤17.15 years, ES = 0.10; p < 0.001), linear sprint time >10 m (>16.3 years, ES = 1.83; ≤16.3 years, ES = 0.36; p = 0.010), and change-of-direction performance time ≤40 m (>16.3 years, ES = 1.65; ≤16.3 years, ES = 0.75; p = 0.005). Greater increases in horizontal jump distance were apparent with >2 compared with ≤2 weekly PJT sessions (ES = 2.12 and ES = 0.39, respectively; p < 0.001).ConclusionData from 32 studies (28 of which demonstrate moderate-to-high methodological quality) indicate PJT improves muscle power, linear sprint speed, change-of-direction speed, balance, and muscle strength in basketball players independent of sex, age, or PJT program variables. However, the beneficial effects of PJT as measured by horizontal jump distance, linear sprint time >10 m, and change-of-direction performance time ≤40 m, appear to be more evident among older basketball players.     

Middle school physical education physical activity quantification: a pedometer steps/min guideline

The objective of the study was to improve physical activity (PA) surveillance of the Healthy People 2010 Objective 22:10 (i.e., 50% of the lesson time engaged in PA) by establishing a pedometer steps/min guideline to quantify time engaged in PA during physical education. A sample of 180 middle school students had their PA measured via pedometry (steps/min) and behavioral observation (PA time). Factorial analyses of variance were used to examine PA differences. Linear and logistic regression, decision accuracy, and receiver-operating-characteristic (ROC) statistics were used to test steps/min cut points against the 50% PA recommendation. PA differences were not found (p > .01). Steps/min was a significant (p < or = .01) predictor of PA time, and the binary outcome of meeting or not meeting the PA recommendation. A steps/min interval of 82-88 was an accurate indicator of the 50% PA recommendation. The ROC statistic was .97 (p < or = .01), suggesting steps/min was an excellent discriminator of the binary outcome. Pedometer steps/min is a valid, objective, and practical approach for surveillance of physical education PA, a key physical education and public health outcome.     

Pedometer-determined physical activity and its comparison with the International Physical Activity Questionnaire in a sample of Belgian adults

Pedometer-determined physical activity (PA) levels in Belgian adults were provided and compared to PA scores reported in the International Physical Activity Questionnaire (IPAQ). The representative sample (N=1239) of the Belgian population took on average 9655 (4526) steps/day. According to pedometer indices 58.4% were insufficiently active. Steps/day differed significantly between gender (F = 5.0, p = .026), age groups (F = 3.3, p = .01), employment status (F = 6.2, p = .013), and days of monitoring (F = 7.4, p = .007). Steps/day were negatively correlated to the time spent sitting and positively to PA at work, in transport, and in leisure time (p < .001). Steps data can discriminate between PA levels reported in the IPAQ. Belgian population pedometer-determined PA levels are higher than those reported in samples of the United States; however, there is a wide distribution of ambulatory behavior     

6-Minute Walk Test Performance in Young Children who are Normal Weight and Overweight

PURPOSE

The primary purpose of this study was to investigate 6-minute walk test (6MWT) performance in young children who were normal weight (NW) and overweight (OW).

METHODS

Seventy children, 5-9 years of age, participated in this study. The 6MWT was performed on an indoor walkway. Heart rate (HR), blood pressure (BP), and oxygen saturation (SaO₂) were measured. A self-reported physical activity questionnaire was completed by a parent/guardian. Data were analyzed with independent t tests, ANOVA, correlation analyses, and logistic regression.

RESULTS

The systolic BP values were higher in the children who were OW compared with their NW peers (resting mean 104.1 (8.9) mmHg vs. 97.5 (7.8) mmHg, P < 0.05; post-6WMT: mean 118.4 (10.78) mmHg vs. 109.9 (9.1) mmHg, P < 0.05). The SaO₂ values were lower in the children who were OW compared to their NW counterparts (resting: mean 97.2 (1.1) % vs. 98.0 (1.0) %, P < 0.05; post-6WMT: mean 96.8 (1.0) % vs. 97.7 (1.0) %, P < 0.05).

CONCLUSIONS

The children who were OW had higher systolic BP and lower SaO₂ levels at rest and post-6WMT. More research is needed to determine if these differences contribute to children who are OW having difficulty performing exercise.Key Words: obesity, children, exercise capacity     

Familial aggregation in physical activity.

The purposes of this study were to (a) examine the stability and consistency of the Caltrac accelerometer (Hemokinetics, Madison, WI) and an activity record to assess physical activity in children and adults (Experiment 1), and (b) to determine if there is a relationship between parents and their children in physical activity level (Experiment 2). Thirty 5-9-year-old children and their biological parents wore Caltrac accelerometers for three consecutive days (including one weekend day). At the same time, parents completed a Caltrac Activity Record (CAL REC) for themselves and their child. Dependent variables were counts per day for the Caltrac and minutes of light activity and activity for the CAL REC. Between-day correlations for the Caltrac ranged from r = .73 to .87 for the parents (p less than .001) and from r = .38 (p less than .04) to .79 (p less than .001) for the children. An analysis of variance with repeated measures indicated no significant differences for the Caltrac between days for parents and children. Between-day correlations for CAL REC ranged from r = .67 to .91 (p less than .05) for parents and r = .36 to .72 (p less than .05) for children, and there were no significant differences between days. In Experiment 2, chi 2 analyses were used to examine familial resemblance in physical activity. Using the Caltrac, familial resemblance occurred in 67% (father and child) and 73% (mother and child) of the families. Using the CAL REC, familial aggregation was present in 70% (father and child) and 66% (mother and child) of the families.(ABSTRACT TRUNCATED AT 250 WORDS)     

幼儿体质影响因素的决策树研究

目的:基于决策树模型探讨幼儿体质的影响因素及其交互关系。方法:募集学龄前儿童4621名(36~83月龄)。参照《国民体质测定标准手册(幼儿部分)》进行体质测试与综合评级(合格、不合格);问卷调查幼儿出生信息、育儿方式、静坐与身体活动、膳食营养、睡眠、父母情况6个一级指标下分的59个二级指标变量信息;采用IBM SPSS modeler创建CHAID决策树模型。结果:幼儿体质的重要影响因素排序依次为周末身体活动(PA)、周末静坐行为(SB)、性别、周末中-大强度身体活动(MVPA)、上学日PA、钙、上学日SB。决策树模型显示,根节点变量周末PA“>3 h/天”(95.35%)的幼儿体质合格率与“1~3 h/天”(91.43%)、“≤0.5 h/天”(85.43%)相比具有非常显著性差异(P=0.000)。周末PA“>3 h/天”的第2、3层叶节点变量分别为周末SB、上学日PA,“1~3 h/天”“≤0.5 h/天”的第2层叶节点变量均为性别。其中,“1~3 h/天”的3~5层叶节点变量包括周末与上学日MVPA、上学日SB、钙等。结论:周末PA是影响幼儿体质的最关键因素。幼儿周末PA应超过3 h/天的国际推荐量标准,并在此基础上减少周末SB时间、增加上学日PA时间。身体活动与静坐行为、性别、钙摄入等对不同层次类型幼儿的体质促进具有决策意义。     

Effects of curricular activity on students' situational motivation and physical activity levels

The purpose of this study was to examine (a) the effects of three curricular activities on students'situational motivation (intrinsic motivation [IM], identified regulation [IR], external regulation, and amotivation [AM]) and physical activity (PA) levels, and (b) the predictive strength of situational motivation to PA levels. Four hundred twelve students in grades 7-9 participated in three activities (cardiovascular fitness, ultimate football, and Dance Dance Revolution [DDR]) in physical education. ActiGraph GT1M accelerometers were used to measure students' PA levels for three classes for each activity. Students also completed a Situational Motivation Scale (Guay, Vallerand, & Blanchard, 2000) at the end of each class. Multivariate analysis of variance revealed that students spent significantly higher percentages of time in moderate-to-vigorous PA (MVPA) in fitness and football classes than they did in DDR class. Students reported higher lM and IR toward fitness than DDR They also scored higher in IR toward fitness than football. In contrast, students displayed significantly lower AM toward fitness than football and DDR Hierarchical Linear Modeling revealed that IM was the only positive predictor for time in MVPA (p = .02), whereas AM was the negative predictor (p < .01). The findings are discussed in regard to the implications for educational practice.     

Using Social Cognitive Theory to Predict Physical Activity and Fitness in Underserved Middle School Children

Abstract

Few researchers have used social cognitive theory and environment-based constructs to predict physical activity (PA) and fitness in underserved middle-school children. Hence, we evaluated social cognitive variables and perceptions of the school environment to predict PA and fitness in middle school children (N = 506, ages 10-14 years). Using multiple regression analyses we accounted for 12% of the variance in PA and 13-21% of the variance in fitness. The best predictors of PA were barrier self-efficacy, classmate social support, and gender; whereas, only gender predicted fitness. The results affirmed the importance of barrier self-efficacy and gender differences. Our findings regarding classmate social support are some of the first to illuminate the importance of school-specific peers in promoting PA.     

Accelerometer-measured daily physical activity related to aerobic fitness in children and adolescents

Maximum oxygen uptake (VO(2PEAK)) is generally considered to be the best single marker for aerobic fitness. While a positive relationship between daily physical activity and aerobic fitness has been established in adults, the relationship appears less clear in children and adolescents. The purpose of this paper is to summarise recently published data on the relationship between daily physical activity, as measured by accelerometers, and VO(2PEAK) in children and adolescents. A PubMed search was performed on 29 October 2010 to identify relevant articles. Studies were considered relevant if they included measurement of daily physical activity by accelerometry and related to a VO(2PEAK) either measured directly at a maximal exercise test or estimated from maximal power output. A total of nine studies were identified, with a total number of 6116 children and adolescents investigated. Most studies reported a low-to-moderate relationship (r = 0.10-0.45) between objectively measured daily physical activity and VO(2PEAK). No conclusive evidence exists that physical activity of higher intensities are more closely related to VO(2PEAK), than lower intensities.     

Associations between showering behaviours following physical education,physical activity and fitness in English schoolchildren

We aimed to describe the frequency of showering after physical education (PE) in English high-school pupils. We examined differences in physical activity (PA) and cardiorespiratory fitness according to showering behaviours and examined predictors of showering. We measured PA and cardiorespiratory fitness of n = 3921 pupils (11–16 years, 53.5% males) from eight high schools. Pupils self-reported showering behaviour and parental PA levels. We calculated deprivation and distance travelled to school from their home postcode. Overall, 53% of boys and 68% of girls said they never shower after PE. Pupils who did not shower after PE were less physically active and engaged in fewer team sports. Girls who did not shower also had lower cardiorespiratory fitness than those who did. Showering behaviour varied greatly by school, so we adjusted for clustering at the school level. Pupils were more likely to shower if they were active with their parents [odds ratio (OR) = 1.72; 95% CI: 1.43, 2.07] and less likely to shower if they were from deprived areas (OR = 0.68; 95% CI: 0.52, 0.88). Showering after PE is relatively rare in English schoolchildren, particularly girls. While we cannot infer causality regarding the relationships found here, the low rates of showering and the lower PA and cardiorespiratory fitness (in girls) observed in schoolchildren who do not shower suggest research is needed to determine whether showering is a barrier to being physically active during PE.     

Quantifying physical activity in first-through fourth-grade physical education via pedometry

The aim of this study was to determine pedometry steps per minute (SPM) cutscores that accurately quantify physical activity (PA) time in first- through fourth-grade physical education. A total of 257 participants were grouped in two data pools, first- and second-grade (n = 126), and third- and fourth-grade (n = 131). Systematic observation was the PA criterion instrument and pedometry was the predictor instrument. Correlations between physical activity measures were strong (r = .82-.89, p < .01). Ten min of PA and 33.33% of the lesson time engaged in PA within a 30-min class can be quantified by 61-63 SPM for first- and second-grade, and 58-61 SPM for third- and fourth-grade. IN CONCOLUSION: (a) SPM values were a valid indicator of students achieving or not achieving PA criteria, and (b) pedometry is a valid and practical tool for physical activity surveillance within physical education.     

Adolescent physical fitness and activity as predictors of adulthood activity

A 25-year population-based study was conducted to determine how physical fitness and participation in leisure-time physical activity in adolescence (age 12-18 years) predict leisure-time physical activity in adulthood (age 37-43 years). In 1976, five field tests were conducted to measure muscular fitness, agility and aerobic capacity, and self-report weekly frequencies of activity were obtained by questionnaire. A modified questionnaire was repeated in 2001, when participants were age 37-43 years (N = 1525). On the basis of the questionnaire, a physical activity index was calculated both in 1976 and 2001. The odds ratios (OR) for being inactive in adulthood among those who were physically very active in adolescence compared with those who were inactive in adolescence was 0.13 for males (95%CI: 0.06-0.31) and 0.28 for females (95%CI: 0.13-0.59). The odds ratio for adult inactivity among males in the highest versus lowest fitness group in adolescence was 0.24 (95%CI: 0.07-0.81). Activity in adolescence predicted activity in adulthood in both males and females. The risk for adult inactivity was significantly lower for those who were physically active in adolescence. In addition, high fitness predicted adult activity among males but not among females.     

Fitness,physical activity and academic achievement in overweight/obese children

ABSTRACT

The aim of this study was to examine the associations of fitness and physical activity with academic achievement in children with overweight/obesity. A total of 106 (10.0 ± 1.1y, 61 boys) children participated. The fitness components were assessed by field and laboratory-based tests. Physical activity was measured via accelerometry. The academic achievement was assessed by a standardised test and school-grades. Field-based cardiorespiratory fitness was associated with language skills (ß-standardised- ranging from 0.281 to 0.365, p < 0.01). The field-based muscular strength was associated with grade point average, natural and social sciences, and foreign language (ß = 0.280–0.326, all p ≤ 0.01). Speed-agility was associated with some language-related skills (ß = 0.325–0.393, all p ≤ 0.01). The laboratory-based muscular strength also showed an association with mathematics skills (ß = 0.251–0.306, all p ≤ 0.01). Physical activity did not show significant association with academic achievement (p > 0.01). Overall, the significant associations observed for muscular strength and speed/agility were attenuated and disappeared in many cases after additional adjustments for body mass index and cardiorespiratory fitness, indicating that these associations are inter-dependent. Our study contributes by indicating that other fitness components apart from cardiorespiratory fitness, such as muscular strength and speed-agility, are positively associated with academic achievement. However, these associations appear to be dependent on body mass index and cardiorespiratory fitness.