BACKGROUND: It is unclear how the amount and intensity of physical activity (PA) are associated with cardiovascular fitness (CVF) and body fatness in children. OBJECTIVE: We aimed to examine the ...associations of total PA and intensity levels to CVF and fatness in children. DESIGN: A cross-sectional study of 780 children aged 9-10 y from Sweden and Estonia was conducted. PA was measured by accelerometry and was expressed as min/d of total PA, moderate PA, and vigorous PA. CVF was measured with a maximal ergometer bike test and was expressed as W/kg. Body fat was derived from the sum of 5 skinfold-thickness measurements. Multiple regression analysis was used to determine the degree to which variance in CVF and body fat was explained by PA, after control for age, sex, and study location. RESULTS: Lower body fat was significantly associated with higher levels of vigorous PA, but not with moderate or total PA. Those children who engaged in >40 min vigorous PA/d had lower body fat than did those who engaged in 10-18 min vigorous PA/d. Total PA, moderate PA, and vigorous PA were positively associated with CVF. Those children who engaged in >40 min vigorous PA/d had higher CVF than did those who accumulated <18 min vigorous PA/d. CONCLUSIONS: The results suggest that PA of vigorous intensity may have a greater effect on preventing obesity in children than does PA of lower intensity, whereas both total and at least moderate to vigorous PA may improve children's CVF.
Abstract Purpose Childhood obesity is one of the major concerns in the last years due to the association with future health problems and all-cause mortality. However, there is a subset of adolescents ...with overweight/obesity who present a metabolic healthy profile. Therefore, the aim of this study was to examine the prevalence of metabolically healthy but overweight/obese adolescents and whether sedentary time, physical activity, and fitness differ between metabolically healthy and nonmetabolically healthy phenotypes. Methods A subsample of 237 European adolescents from the HEalthy Lifestyle in Europe by Nutrition in Adolescence study (n = 3,528, participation rate: 61.3%) with overweight/obesity were included. The study sample was not fully representative for the European adolescent population. Based on sex- and age-specific metabolic syndrome cutoff points for triglycerides, glucose, blood pressure, and high-density cholesterol participants were classified as metabolically healthy or nonmetabolically healthy. Sedentary time, physical activity, and fitness were assessed by accelerometry and the Alpha battery, respectively. Results The prevalence of metabolically healthy status in adolescents with overweight and obesity was higher in girls (87%) than in boys (74%, p = .019), being similar when only obesity was considered. Sedentary time was lower in metabolically healthy overweight/obese than in nonmetabolically healthy participants (mean difference = 48.0 minutes, p = .012). Moderate and moderate-to-vigorous physical activity were higher ( p 's < .05) in metabolically healthy than in nonmetabolically healthy adolescents with overweight/obesity (mean difference = 7.9 min/day and 10.9 min/day, respectively). No significant differences were found in fitness. Overall, these results persisted when only adolescents with obesity were included in the analyses. Conclusions Metabolically healthy adolescents with overweight/obesity are less sedentary and more active than their nonmetabolically healthy peers with overweight/obesity, yet consistent differences in fitness were not observed.
Objectives To explore the associations between objectively assessed intensity levels of physical activity and academic achievement and test whether cardiovascular fitness mediates the association ...between physical activity and academic achievement. Study design Cross-sectional data were gathered in Swedish 9th-grade students (n = 232; mean age = 16 years; 52% girls). School grades, pubertal phase, skinfold thickness, cardiovascular fitness, and physical activity were measured objectively. Mother's education, family structure, and parental monitoring were self-reported. Data were analyzed with linear regression analyses. Results After controlling for confounding factors, academic achievement was associated with vigorous physical activity in girls (β = .30, P < .01; explained variance of the model 26%), which remained after inclusion of fitness (β = .23, P < .05; explained variance 29%). The association was not mediated by fitness. In boys, academic achievement was associated with pubertal phase (β = .25, P < .05). After inclusion of fitness, it was only associated with fitness (β = .25, P < .05; explained variance of the model 30%). Conclusion In girls, academic achievement was associated with vigorous physical activity and not mediated by fitness, whereas in boys only fitness was associated with academic achievement. Further studies are necessary to investigate the potential longitudinal effect of vigorous physical activity on academic achievement, the role of fitness herein and the implications of these findings for schools.
Background: We examined the associations between muscular strength, markers of overall and central adiposity, and cancer mortality
in men.
Methods: A prospective cohort study including 8,677 men ages ...20 to 82 years followed from 1980 to 2003. Participants were
enrolled in The Aerobics Centre Longitudinal Study, the Cooper Institute in Dallas, Texas. Muscular strength was quantified
by combining 1-repetition maximal measures for leg and bench presses. Adiposity was assessed by body mass index (BMI), percent
body fat, and waist circumference.
Results: Cancer death rates per 10,000 person-years adjusted for age and examination year were 17.5, 11.0, and 10.3 across
incremental thirds of muscular strength ( P = 0.001); 10.9, 13.4, and 20.1 across BMI groups of 18.5-24.9, 25.0-29.9, and ≥30 kg/m 2 , respectively ( P = 0.008); 11.6 and 17.5 for normal (<25%) and high percent body fat (≥25%), respectively ( P = 0.006); and 12.2 and 16.7 for normal (≤102 cm) and high waist circumference (>102 cm), respectively ( P = 0.06). After adjusting for additional potential confounders, hazard ratios (95% confidence intervals) were 1.00 (reference),
0.65 (0.47-0.90), and 0.61 (0.44-0.85) across incremental thirds of muscular strength, respectively ( P = 0.003 for linear trend). Further adjustment for BMI, percent body fat, waist circumference, or cardiorespiratory fitness
had little effect on the association. The associations of BMI, percent body fat, or waist circumference with cancer mortality
did not persist after further adjusting for muscular strength (all P ≥ 0.1).
Conclusions: Higher levels of muscular strength are associated with lower cancer mortality risk in men, independent of clinically
established measures of overall and central adiposity, and other potential confounders. (Cancer Epidemiol Biomarkers Prev
2009;18(5):1468–76)
Objectives To examine the associations of physical activity (PA) at different levels and intensities and cardiorespiratory fitness (CRF) with a clustering of metabolic risk factors in children and ...adolescents with special consideration of body fat. Study design Total PA and intensity levels were measured by accelerometry in children (9 years, n = 273) and adolescents (15 years, n = 256). CRF was measured with a maximal ergometer bike test. Measured outcomes included fasting insulin, glucose, triglycerides, total and high-density lipoprotein cholesterol, blood pressure, and body fat. A metabolic risk score (MRS) was computed as the mean of the standardized outcome scores. A “non-obesity-MRS” was computed omitting body fat from the MRS. Analysis of variance and multiple regressions were used in the analysis. Results Total and vigorous PA was inversely significantly associated with MRS in adolescent girls, the group with lowest PA, becoming insignificant when CRF was introduced in the analysis. Significant regression coefficients of total PA and CRF on non-obesity–MRS diminished when body fat was entered in the analysis. Conclusions CRF is more strongly correlated to metabolic risk than total PA, whereas body fat appears to have a pivotal role in the association of CRF with metabolic risk.
Abstract Background/objective Increased physical activity (PA) and decreased sedentary behaviors (SBs) may have beneficial effects on cardio-metabolic risk in adolescents. The aim of this study was ...to examine the associations between independent/combined effects of PA and SB with individual/clustered cardio-metabolic risk factors. Methods A sample of 769 adolescents (12.5–17.5 years) from the HELENA cross-sectional study (Healthy Lifestyle in Europe by Nutrition in Adolescence) and with valid data on metabolic risk factors were included. Results Concerning moderate-to-vigorous-PA (MVPA) and vigorous-PA (VPA), measured with accelerometers, girls tended to do more MVPA (36%) and VPA (114%) than boys. Unadjusted analyses show a positive association between “PA ≥ 60 min/d; SB ≥ 2 h” and the ratio TC/HDL-c (β = 0.27; 95%CI 0.01 to 0.52; p < 0.05), and a negative association between “MVPA ≥ 60 min/d; SB < 2 h” with the ∑ 4Skinfolds (β = − 0.32; 95%CI − 0.61 to − 0.02; p < 0.05). Moreover, “SB ≥ 2 h/d” was associated with increased cardio-metabolic risk (PR 1.59; 95%CI 1.05 to 2.39; p < 0.05), while “PA ≥ 60 min/d; SB < 2 h” had a protective effect against cardio-metabolic risk (PR 0.48; 95%CI 0.25 to 0.91; p < 0.05). After adjustment for potential confounders, a positive association between SB and ∑ 4Skinfolds was shown (β = 0.28; 95%CI 0.04 to 0.53; p < 0.05). Furthermore, VO2 max (mL/kg/min) tends to increase in those participants who do higher VPA and less SB (p = 0.042), and there was a protective effect of “VPA ≥ 30 min/d; SB < 2 h” against cardio-metabolic risk (PR 0.24; 95%CI 0.07 to 0.85; p < 0.05). Conclusion The current study suggests that adolescents should be encouraged to decrease sedentary lifestyle and increase physical activity, especially vigorous physical activity, in order to reduce cardio-metabolic risk.
Objective To examine the association of participation in physical sports activity during leisure time, sedentary behaviors, cardiorespiratory and muscular fitness, and weight status with cognitive ...performance in Spanish adolescents. Study design This cross-sectional study comprised a total of 1820 adolescents (958 female) aged 13.0 to 18.5 years. Cognitive performance (verbal, numeric and reasoning abilities, and an overall score) was measured with the “SRA-Test of Educational Ability.” Participation in physical sports activity during leisure time (yes/no) and time devoted to study, television viewing, and playing video games were self-reported and categorized as ≤3 hours/day and >3 hours/day. We assessed cardiorespiratory and muscular fitness with field-based tests. Adolescents were classified as underweight, normal weight, overweight, and obese. Results Participation in physical sports activities during leisure time was associated with better cognitive performance study variables (all P < .001), independent of potential confounders including cardiorespiratory fitness and body mass index. We did not observe an association of time devoted to study, television viewing, or playing videogames with cognitive performance. Likewise, cognitive performance was similar across cardiorespiratory and muscular fitness levels and body weight categories. Conclusion Participation in physical sports activity during leisure time may positively influence cognitive performance in adolescents.
Background Understanding environmental correlates of physical activity can inform policy changes. Surveys were conducted in 11 countries using the same self-report environmental variables and the ...International Physical Activity Questionnaire, allowing analyses with pooled data. Methods The participating countries were Belgium, Brazil, Canada, Colombia, China (Hong Kong), Japan, Lithuania, New Zealand, Norway, Sweden, and the U.S., with a combined sample of 11,541 adults living in cities. Samples were reasonably representative, and seasons of data collection were comparable. Participants indicated whether seven environmental attributes were present in their neighborhood. Outcomes were measures of whether health-related guidelines for physical activity were met. Data were collected in 2002–2003 and analyzed in 2007. Logistic regression analyses evaluated associations of physical activity with environmental attributes, adjusted for age, gender, and clustering within country. Results Five of seven environmental variables were significantly related to meeting physical activity guidelines, ranging from access to low-cost recreation facilities (OR=1.16) to sidewalks on most streets (OR=1.47). A graded association was observed, with the most activity–supportive neighborhoods having 100% higher rates of sufficient physical activity compared to those with no supportive attributes. Conclusions Results suggest neighborhoods built to support physical activity have a strong potential to contribute to increased physical activity. Designing neighborhoods to support physical activity can now be defined as an international public health issue.
The International Physical Activity Questionnaire (IPAQ) was developed to measure health-related physical activity (PA) in populations. The short version of the IPAQ has been tested extensively and ...is now used in many international studies. The present study aimed to explore the validity characteristics of the long-version IPAQ.
Forty-six voluntary healthy male and female subjects (age, mean +/- standard deviation: 40.7 +/- 10.3 years) participated in the study. PA indicators derived from the long, self-administered IPAQ were compared with data from an activity monitor and a PA log book for concurrent validity, and with aerobic fitness, body mass index (BMI) and percentage body fat for construct validity.
Strong positive relationships were observed between the activity monitor data and the IPAQ data for total PA (rho = 0.55, P < 0.001) and vigorous PA (rho = 0.71, P < 0.001), but a weaker relationship for moderate PA (rho = 0.21, P = 0.051). Calculated MET-h day(-1) from the PA log book was significantly correlated with MET-h day(-1) from the IPAQ (rho = 0.67, P < 0.001). A weak correlation was observed between IPAQ data for total PA and both aerobic fitness (rho = 0.21, P = 0.051) and BMI (rho = 0.25, P = 0.009). No significant correlation was observed between percentage body fat and IPAQ variables. Bland-Altman analysis suggested that the inability of activity monitors to detect certain types of activities might introduce a source of error in criterion validation studies.
The long, self-administered IPAQ questionnaire has acceptable validity when assessing levels and patterns of PA in healthy adults.
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