Children's physical activity and physical self-perceptions

The aim of this study was to determine the relationship between physical self-perceptions and physical activity in Canadian school children aged 10–14 years. The sample consisted of 220 boys and 246 girls in grades 5–8. Physical activity was assessed by 7-day recall using the Physical Activity Questionnaire for Older Children. Selfperceptions of physical conditioning, sports competence, strength, body appearance and general physical selfworth were measured by the Physical Self-Perception Profile (PSPP). We found that boys were more physically active than girls and had higher perceptions of sport competence and strength. All PSPP scales were significantly correlated with physical activity in both boys and girls. Structural equation modelling procedures found the hierarchical PSPP model provided a good fit to the observed data, with little evidence of diff erences between the sexes. Analysis of five alternative structural models of the relationship between the PSPP and physical activity found the most parsimonious model to have significant pathways from both physical conditioning and sport skills to physical activity. Models for the sample as a whole, for boys and for girls were similar, accounting for an R 2 of 0.27–0.29 for physical activity. Our results demonstrate that physical self-perceptions, especially physical conditioning and sport skills, are significant correlates of activity in this population.     

Children's physical activity and physical self-perceptions

The aim of this study was to determine the relationship between physical self-perceptions and physical activity in Canadian school children aged 10-14 years. The sample consisted of 220 boys and 246 girls in grades 5-8. Physical activity was assessed by 7-day recall using the Physical Activity Questionnaire for Older Children. Self-perceptions of physical conditioning, sports competence, strength, body appearance and general physical self-worth were measured by the Physical Self-Perception Profile (PSPP). We found that boys were more physically active than girls and had higher perceptions of sport competence and strength. All PSPP scales were significantly correlated with physical activity in both boys and girls. Structural equation modelling procedures found the hierarchical PSPP model provided a good fit to the observed data, with little evidence of differences between the sexes. Analysis of five alternative structural models of the relationship between the PSPP and physical activity found the most parsimonious model to have significant pathways from both physical conditioning and sport skills to physical activity. Models for the sample as a whole, for boys and for girls were similar, accounting for an R2 of 0.27-0.29 for physical activity. Our results demonstrate that physical self-perceptions, especially physical conditioning and sport skills, are significant correlates of activity in this population.     

论体力活动与学校体育

深入探讨了体力活动的定义、理论意义，体力活动在学校体育中的理论地位以及体力活动的相关知识和技能对学生体育实践的意义，以引起学校体育工作对这一概念的重视。     

Longitudinal associations between motor competence and different physical activity intensities: LabMed physical activity study

An appropriated level of motor competence is essential for children´s healthy growth and development and a key factor in the promotion of lifelong active lifestyles and health.

The purpose of this study was to examine associations between motor competence and different physical activity intensities (light, moderate, moderate-to-vigorous and vigorous physical activity), as well as total physical activity, over a two-year period, in adolescents. The sample comprised of 103 adolescents (13.49 ± 0.87 years, 53 girls), from the north of Portugal. Motor competence was evaluated with the body coordination test, Körperkoordination-Test-für-Kinder. Physical activity was objectively assessed with GT1M accelerometers (ActiGraph, Pensacola, FL, USA). Physical activity variables were expressed as proportions of accelerometer wear time. Regression analyses showed positive longitudinal associations between motor competence at baseline and moderate physical activity (B = 0.0033, p = 0.018), moderate-to-vigorous physical activity (B = 0.0052, p = 0.024) and total physical activity (B = 0.067, p = 0.040) at follow up, after adjustments for age, sex, the corresponding physical activity intensity at baseline, body mass index, pubertal stage and socioeconomic status. Our ?ndings highlight the importance of motor competence development to promote moderate-to-vigorous physical activity during adolescence.     

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.     

Biological maturity and primary school children's physical activity: Influence of different physical activity assessment instruments

Abstract

Biological maturation may attenuate hypothesized sex differences in children's physical activity but overall the evidence for this is equivocal. In this study, we investigated how the selection of different physical activity assessment instruments affects the detected relationship between biological maturation and late primary school children's physical activity. Altogether, 175 children (97 girls, 78 boys) aged 10.6±0.3 years completed the PAQ-C self-report questionnaire and wore ActiGraph GT1M accelerometers for 5 consecutive days. Maturity status was predicted by estimating attainment of age at peak height velocity. Following initial exploration of sex differences in PAQ-C (t-test) and multiple ActiGraph outcome variables (MANOVA), the influence of maturity status was controlled using ANCOVA and MANCOVA. Unadjusted analyses revealed that boys were significantly more active than girls according to the PAQ-C (P<0.0001, d=0.52) and ActiGraph (P<0.0001, d=0.36–0.72). After controlling for maturity status, the differences in PAQ-C scores increased (P=0.001, d=0.64), but the significant differences disappeared for the ActiGraph data (P=0.36, d=0.17–0.33). The detected relationship between maturity status and late primary school children's physical activity is dependent on the physical activity assessment tool employed, reflecting the different aspects of physical activity captured by the respective measures.     

Tracking of physical activity in adolescence

The present analysis aimed to describe the degree of tracking of physical activity over an 8-year follow-up period among a cohort of 557 adolescents in western Norway (13 years of age at baseline). Frequency and time spent in leisure-time physical activity were assessed at ages 13, 14, 15, 16, 18, 19 and 21 years through self-report questionnaires. The cross-sectional results indicated that proportions of adolescents who were physically active declined from 13 to 19 years of age and increased slightly from 19 to 21 years of age. Longitudinally, various measures indicated a weak degree of tracking of physical activity (Pearson's r was .22 for boys and. 18 for girls across the 8-year period). The least active persons during early adolescence were those least likely to change during their teenage years. In sum, the findings indicated a weak tendency of tracking of physical activity through adolescence.     

Exercise science and health-enhancing physical activity

Although technology has now infiltrated and prompted evolution in most mass participation sports, the advances in bat technology in such sports as baseball and cricket have been relatively minor. In this study, we used a simple finite element modelling approach to try to shed new light upon the underlying mechanics of the bat-ball impact, with a view to the future optimization of bat design. The analysis of a flexible bat showed that the point of impact that produced the maximum post-impact ball velocity was a function of the bat's vibrational properties and was not necessarily at the centre of percussion. The details of the analysis agreed well with traditional Hertzian impact theory, and broadly with empirical data. An inspection of the relative modal contributions to the deformations during impact also showed that the position of the node of the first flexure mode was important. In conclusion, considerable importance should be attached to the bat's vibrational properties in future design and analysis.     

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)     

Pedometer-assessed physical activity in young adolescents

The purpose of this study was to evaluate the physical activity (PA) patterns of children. Forty-four 7th-grade students (19 boys, 25 girls) recorded pedometer data for 2 consecutive weeks. Separate 2 x 3 repeated measures analyses of variance were used to examine differences in total steps/day between boys and girls and between after-school activity participants and nonparticipants. The relative contribution of physical education (PE) and after-school activity (ASA) to weekday steps/day was evaluated as a proportion, for example (steps taken in PE class/total daily steps taken on a PE class day) * 100. The total sample mean was 11,392 steps/day, SD = 4112; for boys, M = 12,490 steps/day, SD=3910, versus girls, M = 10,557 steps/day, SD=4142; F=(1, 42) 4.365, p = .043. The sample population averaged 2046 steps, SD=945, during PE class; boys=2379 steps, SD=1115, versus girls=1782, SD=703; t (42) = 2.15, p = .038, d = .65, which represented 18% of the total steps/day on PE days. In comparison, the participants accumulated an average of 5366 steps, SD=2590; ASA for boys=5897 steps/day, SD=2738, versus girls=4963 steps/day, SD=2450; t (42) = 1.190, p = .241, d = .36), representing 46% of the steps/day on all weekdays and 47% of the total on PE days. Expressed as a rate, the sample population took 45.5 steps/min (SD=21) during PE class and 13.1 steps/min (SD = 4.7) in ASA on all weekdays. The relative stability of day-to-day behavior in youth is a preliminary finding but noteworthy. Although the absolute contribution ofPE class to daily PA was less than ASA (i.e., 18 vs. 47%, respectively), the importance of the condensed contribution in class was evident when these two activities were expressed as rates (i.e., steps/min). These data indicate that youth involved in ASA accumulated a greater number of steps on all days, weekend days, and health education days when compared to youth not involved in ASA.     

Impact of physical activity domains on subsequent physical activity in youth: a 5-year longitudinal study

This study evaluates how domains of physical activity (PA) in youth predict later PA and assesses factors influencing changes in sports participation. Young people from the Children’s Sport Participation and Physical Activity study (n = 873; baseline age 10–18 years; 30.4% male) completed self-report surveys in 2009 and 2014. In a multiple linear regression analysis, participation frequency in club sport (β = 0.18) and extracurricular sport (β = 0.13) significantly predicted PA 5 years later, adjusted for age, sex and urban/rural classification (P < 0.01). Overall, rates of regular (at least once per week) youth sports participation were high (males 79.3–85.5%; females 74.8–83.2%). Uptake and dropout of specific sports varied widely. Despite high levels of migration into and out of Gaelic games, they remained popular at follow-up. Weight training was the only sport that increased in both sexes (P < 0.05). Fitness, friends and enjoyment were top motivations for taking up a new sport. Other commitments, a lack of interest and time were important factors leading to sports dropout. PA promotion strategies should include youth sport, take into consideration what sports are attractive to young people and address reasons for uptake and dropout.     

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.     

The influence of self-determination in physical education on leisure-time physical activity behavior

Using a multitheory approach, this study was designed to investigate the influence of urban adolescents' perceived autonomy and competence in physical education on their physical activity intentions and behaviors during leisure time. A transcontextual model was hypothesized and tested. Urban adolescents (N=653, ages 11-15 years) completed questionnaires assessing relevant psychological constructs and moderate to vigorous physical activity and then had their cardiorespiratory fitness assessed with the Progressive Aerobic Cardiovascular Endurance Run (PACER) test. Based on our structural equation modeling analyses and fit indexes, the transcontextual model adequately fit the data. We concluded that the two theoretical frameworks--SDT and theory of planned behavior--can be integrated to provide an enhanced understanding of the influence of physical education on leisure-time physical activity. The results revealed that perceived autonomy and competence in physical education are interrelated and function as a whole for enhancing leisure-time physically active intentions and behavior.     

A prospective study of pedometer-determined physical activity and physical self-perceptions in children

There have been limited prospective studies investigating physical activity and physical self-perceptions in children. In this investigation, mean steps/day did not significantly change from late elementary to junior high for either boys or girls; however; boys accumulated more steps both at baseline and follow-up. Physical self-perception measures were significantly related to changes in steps/day and accounted for 21% (15% adjusted) of the variance after controlling for demographic/biological variables, R2 change = .21, adjusted R2 change = .15, F (5,88) = 4.66, p < .001. Sport competence emerged as the most important predictor t (88) = -3.76, p < .001, and was inversely related to physical activity change. The lack of opportunities to participate in sport activities normally found at the onset of adolescence may help explain this unexpected result.     

Motivational processes in physical education and objectively measured physical activity among adolescents

PurposeGrounded in self-determination theory (SDT), the present study tested how students’ perceptions of autonomy support from physical education teachers predicts objectively measured moderate-to-vigorous physical activity (MVPA) of adolescents. According to SDT, it was expected that psychological needs and autonomous and controlled forms of motivation would mediate these relationships.MethodsStudents (n = 397) aged from 11 to 15 years in 17 different schools filled in questionnaires regarding SDT variables. In addition, objective MVPA was measured using an accelerometer (ActiGraph GT3X; ActiGraph, Pensacola, FL, USA) for 7 days. Structural equation modelling was used to examine the hypothesized relationships among the study variables.ResultsThe theory-based model showed a good fit with the data: χ² = 642.464, df = 257; comparative fit index = 0.932; non-normed fit index = 0.921; root mean square error of approximation = 0.062; root mean square error of approximation 90% confidence interval: 0.054–0.067. As hypothesized, there was a significant and positive direct relationship between autonomy support and need satisfaction (β = 0.81, p = 0.001). In turn, need satisfaction positively predicted intrinsic motivation (β = 0.86, p = 0.001). Intrinsic motivation was positively related to MVPA (β = 0.29, p = 0.009). A significant indirect effect (β = 0.20, p = 0.004) supported the mediating role of psychological need satisfaction and intrinsic motivation in the relationship between perceived autonomy support and objectively measured MVPA.ConclusionThe findings of the current study support the applicability of the SDT-based model in explaining the antecedents of objectively measured MVPA of adolescents. To enhance adolescents’ daily MVPA, special focus should be put on increasing their intrinsic motivation toward physical education.     

Impact of compliance with different guidelines on physical activity during pregnancy and perceived barriers to leisure physical activity

Abstract

The aims of the this prospective study were to analyse physical activity (PA) engagement during the first and second trimesters, considering the different guidelines published on PA, to document the individual characteristics associated with the accomplishment of these guidelines and to examine pregnant women’s perceived barriers to leisure PA, using a socioecological framework. A sample of 133 pregnant women in two stages – at 10–12 weeks’ gestation (T1) and 20–22 weeks’ gestation (T2) – were evaluated. PA was assessed by accelerometry during the T1 and T2 evaluation stages. Socio-demographic characteristics, lifestyle factors and barriers to leisure PA were assessed via questionnaire. A large proportion of women (ranging from 32% to 96%) did not reach the levels of PA recommended by the guidelines. There were no significant differences between T1 and T2 with regard to compliance with PA recommendations. A decrease in PA levels from T1 to T2 was noted for all recommendations. No associations were found between participants’ characteristics and adherence to the recommendations in T1 and T2. No significant differences were found in barriers to leisure PA between T1 and T2. The most commonly reported barriers to leisure PA were intrapersonal, not health related. Our results indicate that there were no differences between trimesters regarding compliance of PA recommendations, and perceived barriers were similar in both trimesters.