Healthy Cardiorespiratory Fitness Research Articles

Sleep duration and cardiorespiratory fitness in adolescents: Longitudinal analysis from the LabMed study.

We aimed to investigate longitudinal associations between sleep duration and cardiorespiratory fitness, in adolescents. Sleep duration was self-reported and cardiorespiratory fitness was assessed by the 20 m shuttle run test, both at baseline and follow-up (2-year follow-up). Participants were 734 Northern Portuguese adolescents (349 girls), aged 14.6 ± 1.8 years, from the LabMed study. Significant decreases were found between baseline and follow-up for sleep duration, whereas for cardiorespiratory fitness there was an increase. Adolescents with short sleep duration at baseline had lower cardiorespiratory fitness at follow-up, comparing to those meeting the sleep guidelines (odds ratio [OR] = 0.506, 95% confidence interval [CI]: 0.326-0.785; p = .002 for whole week; OR = 0.597, 95% CI: 0.407-0.875; p = .008 for weekdays). Girls who were short sleepers at baseline had lower odds of having a healthy cardiorespiratory fitness at follow-up, comparing to those meeting the sleep guidelines (OR = 0.311, 95% CI: 0.158-0.613; p < .001 for whole week; OR = 0.469, 95% CI: 0.262-0.838; p = .011 for weekdays). No significant associations between sleep duration and cardiorespiratory fitness were found for boys. There was a significant longitudinal association between short sleep duration and lower cardiorespiratory fitness levels, particularly in girls. Future interventions targeting adolescents' sleep duration should acknowledge behavioral differences between genders, as well as different behaviors adopted by boys ang girls, specifically on weekends.

Physical fitness in children and adolescents with inflammatory bowel disease: protocol for a case–control study

IntroductionInflammatory bowel disease (IBD) is a chronic disorder of the gastrointestinal tract, associated with adverse health consequences that may adversely influence physical activity and body composition in youth. These effects...

Development of Cardiorespiratory Fitness in Children in the Transition From Kindergarten to Basic School According to Participation in Organized Sports.

Purpose: This study examined the development of cardiorespiratory fitness (CRF) in children in the transition from kindergarten to basic school according to participation in organized sports and estimated the associations of CRF and body composition indices during the transition from childhood to preadolescence. Methods: Children participated in the three-staged study (kindergarten, 6.6 years, n = 212; 1st grade, 7.6 years, n = 136; and 5th grade, 11.5 years, n = 142) for 5 years and were categorized into three groups according to their participation in organized sports in the study period (whole period, episodically, and never). Cardiorespiratory fitness was assessed by performing a 20-m shuttle run test, while body composition was measured by skinfold thicknesses, and physical activity was registered with an accelerometer. International gender- and age-specific CRF reference normativities were also used to characterize the participants. Results: Children who participated consistently in organized sports had significantly higher CRF levels and lower body fatness (31.3 ± 13.5 laps in 20 m shuttle run; 21.1% ± 6.3% body fat) in 11.5 years than in children who had never participated in sports clubs (20.7 ± 12.0 laps in 20-m shuttle run; 26.1% ± 6.8% body fat). Body composition and CRF did not associate in consistently trained children. The proportion of 5th grade children demonstrating age-appropriate healthy CRF was almost threefold higher in the group of consistent sports training among both boys and girls than among non-members of sports clubs. Conclusion: Consistent attendance in organized sports in childhood and early preadolescence ensures higher CRF and healthier body composition than in children who had no experience of organized sports.

School time is associated with cardiorespiratory fitness in adolescents: The HELENA study

ABSTRACT We assessed the association between school time and physical fitness in adolescents. The study included 2,024 adolescents, aged 12.5–17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Health-related physical fitness components were assessed using the physical fitness tests battery. Cardiovascular risk was categorized using the sex-specific cut-offs for a healthy cardiorespiratory fitness level in adolescents proposed by FitnessGram®. School time was classified as short or long. Multivariate analysis accounted for confounding factors such age, sex, body mass index, time spent in moderate to vigorous physical activity, pubertal status, and parents’ educational level. Cardiorespiratory fitness was higher in adolescents with a long school time than in those with a short school time (42.0 ± 7.6 vs 40.7 ± 7.2 mL.kg–1.min–1, respectively; p < 0.05). The percentage of adolescents at cardiovascular risk in adulthood was higher in the short than in the long time group (45.2% vs 31.7%, respectively) (p < 0.05). These findings suggest that a long school day is associated with higher cardiorespiratory fitness in adolescents and that school time should be considered in interventions and health promotion strategies.

Cardiorespiratory Fitness in Youth: An Important Marker of Health: A Scientific Statement From the American Heart Association.

Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. CRF is an important marker of physical and mental health and academic achievement in youth. However, only 40% of US youth are currently believed to have healthy CRF. In this statement, we review the physiological principles that determine CRF, the tools that are available to assess CRF, the modifiable and nonmodifiable factors influencing CRF, the association of CRF with markers of health in otherwise healthy youth, and the temporal trends in CRF both in the United States and internationally. Development of a cost-effective CRF measurement process that could readily be incorporated into office visits and in field settings to screen all youth periodically could help identify those at increased risk.

Normal-Weight Obesity Is Associated with Poorer Cardiometabolic Profile and Lower Physical Fitness Levels in Children and Adolescents.

Normal-weight obesity (NWO) syndrome has been shown to be associated with cardiometabolic dysfunction. However, little is known regarding this potential relationship in Latin American children and adolescents. The aim of this study was two-fold: (i) to investigate whether Colombian youth with NWO syndrome have a poorer cardiometabolic profile and physical fitness performance than normal-weight lean (NWL) peers; and (ii) to determine if physical fitness levels are related to prevalence of normal-weight obesity in youth. This was an analytical cross-sectional study of 1919 youths (9–179 years old, 53.0% girls) in the capital area of Colombia. NWO was defined as a body mass index < 25 kg/m2 and a validated body fat percentage above the sex-age-specific 90th percentile for Colombian children and adolescents. Body fat was estimated using bioelectrical impedance analysis, cardiorespiratory fitness (CRF) was estimated using the 20-meter shuttle run test, and muscular fitness with the handgrip test. Biochemical profile blood samples were collected for cardiometabolic risk factors. After adjusting for chronological age, pubertal stage, and Mediterranean diet adherence, the NWO group (boys and girls) had significantly higher values for cardiometabolic risk factors, and waist circumference (WC) than the NWL group. The prevalence of NWO was lower in youth classified with healthy CRF (boys, odds ratio (OR) = 0.54, 95% confidence interval (CI) 0.37 to 0.78; girls, OR = 0.35, 95% CI 0.24 to 0.50), p < 0.001. Our findings indicate that using only body mass index for the assessment of cardiometabolic risk likely misrepresents true adiposity and suggest the need to include the assessment of body fat in the routine clinical evaluation of individuals during childhood and adolescence.

Criterion-referenced mCAFT cut-points to identify metabolically healthy cardiorespiratory fitness among adults aged 18-69 years: an analysis of the Canadian Health Measures Survey.

This study aimed to develop and validate health-related criterion-referenced cut-points for the modified Canadian Aerobic Fitness Test (mCAFT), a field-based measure to predict cardiorespiratory fitness among adults (18-69 years). Criterion-referenced mCAFT cut-points were developed using nationally representative data from cycles 1 (2007-2009) and 2 (2009-2011) of the Canadian Health Measures Survey (CHMS). Receiver operating characteristic curves were used to identify age- and sex-specific cut-points for measured waist circumference, blood pressure, and high-density lipoprotein. Cut-points were validated against metabolic syndrome using a fasted subsample (n = 1093) from cycle 5 (2016-2017). For the main analyses, 4967 participants (50% women) were retained. The mCAFT cut-points ranged from 28 to 43 mL·kg-1·min-1 (area under the curve (AUC): 0.60-0.87) among men, and 23 to 37 mL·kg-1·min-1 (AUC: 0.61-0.86) among women. The likelihood of meeting the new mCAFT cut-points decreased with an increase in the presence of metabolic risk factors. In total, 54% (95% confidence interval: 42% to 67%) of Canadian adults met the new mCAFT cut-points in 2016-2017. This study developed and validated the first health-related criterion-referenced mCAFT cut-points for metabolic health among Canadian adults aged 18-69 years. These mCAFT cut-points may be useful in health surveillance, clinical, and public health settings. Novelty We developed and validated new criterion-referenced cut-points for the mCAFT to help identify adults at potential risk of poor metabolic health. These new cut-points could help support national health surveillance efforts.

Association of Adherence to Specific Mediterranean Diet Components and Cardiorespiratory Fitness in Young Adults.

Objective: Cardiorespiratory fitness (CRF) and a healthy diet may be part of an overall healthy lifestyle. The association between cardiorespiratory fitness and adherence to an overall Mediterranean Diet (MedD) pattern and specific MedD foods has been assessed. Design: Subjects completed a lifestyle survey and dietary pattern, using the validated MedD Adherence 14-item questionnaire and two self-reported 24-h dietary recalls. Participants’ height, body weight, waist circumference (WC), and CRF (maximum oxygen uptake, VO2max, ml/kg/min) were measured. Setting: University of Cádiz, Spain. Subjects: A sample of young adults (n = 275, 22.2 ± 6.3 years). Results: Mean VO2max was 43.9 mL/kg/min (SD 8.5 mL/kg/min). Most participants had healthy CRF (75.9%). The average MedD score was 6.2 points (SD 1.8 points). Participants who consumed more servings of nuts had higher VO2max. Those who showed low CRF performed less physical activity (PA) and had a higher body mass index (BMI) and WC compared with those classified as having healthy CRF. Nut consumption was positively associated with VO2max (β = 0.320; 95% CI 2.4, 10.7; p < 0.002), adjusting for sex, age, smoking PA, BMI, WC, and energy intake, showing the subjects who consumed more nuts were fitter than young adults who consumed less. Conclusions: CRF is positively associated with nut consumption but not with the overall MedD pattern and all other MedD foods in the young adults. The subjects who consumed more servings of nuts were fitter than young adults who consumed less. Moreover, fitter subjects performed more PA and had a lower BMI and WC than those who had lower fitness levels.

Exclusive olive oil consumption was favorably associated with metabolic indices and lifestyle factors in schoolchildren

Background and aimOlive oil consumption has been suggested to favorably impact children's health. The present study aimed to identify possible associations between exclusive olive oil consumption and metabolic indices and lifestyle factors. Methods and resultsCross-sectional, observational study. Population data derived from a health survey on a sample of 177 091 children aged 8–17 years. Olive oil consumption and dietary habits were evaluated using questionnaires (KIDMED index). Anthropometric and physical fitness measurements were obtained by trained investigators. Physical activity (PA) status, screen time and sleeping habits were assessed through self-completed questionnaires. Exclusive olive oil consumption decreased the odds of obesity and increased the odds of healthy cardiorespiratory fitness (CRF) by 15% (95% confidence interval (CI): 0.75–0.95) and 13% (95% CI: 1.04–1.22), respectively, after adjusting for several covariates. Moreover, exclusive olive oil consumption was associated with increased odds of having sufficient dietary habits (average/optimal adherence to the Mediterranean Diet) by almost four times (95% CI: 3.65–4.45) and decreased odds of insufficient sleep (<8–9 h/d) and increased screen time (>2 h/d) by 20% (95% CI: 0.73–0.87) and 40% (95% CI: 0.48–0.72), respectively. ConclusionsExclusive olive oil consumption was associated with metabolic indices such as obesity and CRF and a healthy lifestyle profile. The exclusive consumption of olive oil as part of a balanced MD does seem to provide favorable health benefits and should be further promoted.

Health‐related physical fitness and weight status in 13‐ to 15‐year‐old Latino adolescents. A pooled analysis

ObjectiveThe aim of this study was to investigate the relation between health‐related physical fitness and weight status in 13‐ to 15‐year‐old Latino adolescents. MethodThe final sample consisted of 73,561 adolescents aged 13–15 years (35,175 girls) from Chile (n=48,771) and Colombia (n=24,790). Cardiorespiratory and musculoskeletal fitness were measured using 20‐m shuttle run (relative peak oxygen uptake – VO2peak) and standing broad jump test (lower body explosive strength), respectively. The International Obesity Task Force definition was used to define weight status (i.e., underweight, normal weight, overweight, and obese). ResultsThe present study found an inverted J‐shape relationship between body mass index, cardiorespiratory fitness, and musculoskeletal fitness in both genders and all age groups (p<0.01). Results also suggest that underweight adolescents, and not just overweight and obese adolescents, have lower odds of having a healthy cardiorespiratory fitness (based on new international criterion‐referenced standards) profile when compared with their normal weight peers, except in girls aged 14 (p=0.268) and 15 years (p=0.280). ConclusionsThe present results indicate low cardiorespiratory fitness and musculoskeletal fitness levels in underweight, overweight, and obese adolescents when compared with their normal weight peers. The findings appear to suggest that exercise programs should to decrease fat mass in overweight/obese adolescents and increase muscle mass in underweight adolescents.

Association of cardiorespiratory fitness levels with dietary habits and lifestyle factors in schoolchildren

This study examined the association between cardiorespiratory fitness (CRF) levels and lifestyle factors in a representative sample of Greek schoolchildren. In 2015, a health survey was carried out in 177 091 participants 8-17 years of age. Dietary habits, sleeping hours, physical activity (PA), and sedentary activities were assessed through self-completed questionnaires. CRF was evaluated with a 20-m shuttle run test. Insufficient dietary habits were greater in boys and girls classified as having low CRF than in their peers with healthy CRF. Skipping breakfast (odds ratio (OR), 0.82; 95% confidence interval (CI) 0.79-0.85), fast food consumption (OR, 0.70; 95% CI 0.68-0.72), and regular sweet intake (OR, 0.79; 95% CI 0.76-0.82) decreased the odds of having a healthy CRF level. An increase in age by 1 year (OR, 0.71; 95% CI, 0.70-0.72), overweight/obesity (OR, 0.30; 95% CI 0.29-0.31), and insufficient sleep duration (OR, 0.74; 95% CI 0.72-0.76) decreased the odds of a healthy CRF level, whereas sufficient dietary habits and adequate PA levels increased a participant's odds of having a healthy CRF level, by 48% and 40%, respectively. Although the mechanisms via which CRF may be influenced by dietary habits remain unclear, health policy-makers should consider opportunities for improving both CRF and dietary habits.

Health-related physical fitness and weight status in 13- to 15-year-old Latino adolescents. A pooled analysis

ObjectiveThe aim of this study was to investigate the relation between health-related physical fitness and weight status in 13- to 15-year-old Latino adolescents. MethodThe final sample consisted of 73,561 adolescents aged 13–15 years (35,175 girls) from Chile (n=48,771) and Colombia (n=24,790). Cardiorespiratory and musculoskeletal fitness were measured using 20-m shuttle run (relative peak oxygen uptake – VO2peak) and standing broad jump test (lower body explosive strength), respectively. The International Obesity Task Force definition was used to define weight status (i.e., underweight, normal weight, overweight, and obese). ResultsThe present study found an inverted J-shape relationship between body mass index, cardiorespiratory fitness, and musculoskeletal fitness in both genders and all age groups (p<0.01). Results also suggest that underweight adolescents, and not just overweight and obese adolescents, have lower odds of having a healthy cardiorespiratory fitness (based on new international criterion-referenced standards) profile when compared with their normal weight peers, except in girls aged 14 (p=0.268) and 15 years (p=0.280). ConclusionsThe present results indicate low cardiorespiratory fitness and musculoskeletal fitness levels in underweight, overweight, and obese adolescents when compared with their normal weight peers. The findings appear to suggest that exercise programs should to decrease fat mass in overweight/obese adolescents and increase muscle mass in underweight adolescents.

European normative values for physical fitness in children and adolescents aged 9–17 years: results from 2 779 165 Eurofit performances representing 30 countries

ObjectiveTo develop sex-specific and age-specific normative values for the nine Eurofit tests in European children and adolescents aged 9–17 years.MethodsA systematic review was undertaken to identify papers that explicitly reported...

Review of criterion-referenced standards for cardiorespiratory fitness: what percentage of 1 142 026 international children and youth are apparently healthy?

To identify criterion-referenced standards for cardiorespiratory fitness (CRF); to estimate the percentage of children and youth that met each standard; and to discuss strategies to help improve the utility of criterion-referenced standards for population health research. A search of four databases was undertaken to identify papers that reported criterion-referenced CRF standards for children and youth generated using the receiver operating characteristic curve technique. A pseudo-dataset representing the 20-m shuttle run test performance of 1 142 026 children and youth aged 9-17 years from 50 countries was generated using Monte Carlo simulation. Pseudo-data were used to estimate the international percentage of children and youth that met published criterion-referenced standards for CRF. Ten studies reported criterion-referenced standards for healthy CRF in children and youth. The mean percentage (±95% CI) of children and youth that met the standards varied substantially across age groups from 36%±13% to 95%±4% among girls, and from 51%±7% to 96%±16% among boys. There was an age gradient across all criterion-referenced standards where younger children were more likely to meet the standards compared with older children, regardless of sex. Within age groups, mean percentages were more precise (smaller CI) for younger girls and older boys. There are several CRF criterion-referenced standards for children and youth producing widely varying results. This study encourages using the interim international criterion-referenced standards of 35 and 42 mL/kg/min for girls and boys, respectively, to identify children and youth at risk of poor health-raising a clinical red flag.

Serum Adiponectin Levels and Cardiorespiratory Fitness in Nonoverweight and Overweight Portuguese Adolescents: The LabMed Physical Activity Study.

This study examined the independent associations between cardiorespiratory fitness and circulating adiponectin concentration in adolescents, controlling for several potential covariates. This is a cross-sectional study in Portuguese adolescents. A sample of 529 (267 girls) aged 12-18 years were included and categorized as overweight and nonoverweight. Cardiorespiratory fitness was assessed by 20 meters shuttle run test. We measured serum adiponectin, high-sensitivity C-reactive protein, fasting glucose, insulin and HDL-cholesterol. After adjustment for age, sex, pubertal stage, adherence to the Mediterranean diet, socioeconomic status, body fat percentage, insulin resistance, HDL-cholesterol and C-reactive protein, regression analysis showed a significant inverse association between adiponectin and cardiorespiratory fitness in nonoverweight participants (B=-0.359; p < .042). Analysis of covariance showed a significant difference between the highest cardiorespiratory fitness Healthy zone (above healthy zone) and the Under and the Healthy cardiorespiratory fitness zones in nonoverweight adolescents (p = .03) (F (2, 339) = 3.156, p < .001). Paradoxically, serum adiponectin levels are inversely associated with cardiorespiratory fitness in nonoverweight, but not in overweight adolescents. In nonoverweight adolescents, those with highest levels of cardiorespiratory fitness (above healthy zone) presented lower levels of adiponectin compared with those in Under and Healthy cardiorespiratory fitness zones.

Capacidad aeróbica y su relación con parámetros de la condición física saludable en escolares

Background and objective: The aim of this study was to analyze the relationship between aerobic capacity and other parameters determining fitness in primary school. Methods: A cross-sectional descriptive study, 298 schoolchildren (139 males and 159 females) aged 8-12. Body composition (weight and height) and physical fitness (capacity, motor aerobic and musculoskeletal) was assessed by ALPHA-Fitness battery. Aerobic capacity and body mass index (under/normal-weight and overweight/obesity) were categorized using standard criteria. The variable motor / muscle overall capacity was calculated, and the maximum oxygen consumption (VO2max) was indirectly estimated. Results: The analysis of covariance (ANCOVA) found that men have better values in the test 4x10m (p &lt;0.001), longitudinal jump (p &lt;0.001), Course-Navette (p &lt;0.001) and in VO2max (p &lt;0.001). The ANOVA test showed that schoolchildren with better aerobic capacity have lower weight and body mass index (p &lt;0.001 for both), better performance in the test longitudinal jump (p &lt;0.001) and better overall motor / muscle capacity, and increased VO2max (p &lt;0.001 for both). Conclusion: The results of this study suggest that schoolchildren with healthy cardiorespiratory fitness had better physical fitness and are more likely to have healthy anthropometric parameters.

Nationally Representative Associations between Health-Related Physical Fitness and Standardized Academic Test Scores in Chilean Adolescents

Physical fitness has been positively related to academic performance in youth, yet this association has not been examined at a national level for cardiorespiratory fitness (CRF) and musculoskeletal fitness (MSF). PURPOSE: To examine the independent and combined associations of CRF and MSF with academic performance in Chilean 8th graders. METHODS: This cross-sectional study was based on a population-based, representative sample of 18,696 8th graders (median age=14 years) who were sampled in both the 2011 National Physical Education Survey and the 2011 National Academic Achievement Survey in Chile. Academic performance was assessed via four standardized tests: reading, math, natural science, and social sciences (max average score of all tests=404.0; min=132.8; mean=257.3). CRF was assessed with the 20-meter shuttle run test and MSF with standing broad jump. The independent associations of CRF and MSF with the mean of the four academic test scores were determined through multivariate linear regression. The combined influence of CRF and MSF on academic achievement was determined using ANCOVA with a three-level dependent variable: 1) unhealthy CRF and unhealthy MSF; 2) either unhealthy MSF or unhealthy CRF; 3) healthy MSF and healthy CRF. Both models controlled for body mass index, waist circumference, socioeconomic status, age, sex, and geographical location. Analyses were weighted and accounted for complex sampling design. RESULTS: MSF was positively associated with academic performance scores (beta=0.09, p<0.001), independent of CRF and other covariates, whereas CRF was not significantly associated with academic scores, after controlling for MSF and other covariates. Students with both unhealthy CRF and unhealthy MSF had poorer academic scores (adjusted mean score=253.2) than students with either unhealthy CRF or MSF (adjusted mean=256.9), who had yet poorer academic performance than students with healthy CRF and healthy MSF (adjusted mean=258.9; p for trend <0.001). CONCLUSIONS: Unhealthy MSF was associated with poorer academic scores in Chilean adolescents. When combined with unhealthy CRF, this effect intensified. Results are in line with previous studies finding a link between physical fitness and academic achievement in youth, this time at a nationally representative level. The findings may have implications for education policy in Chile.

Abstract 61: Associations of Cardiorespiratory and Musculoskeletal Fitness with Body Mass Index and Waist Circumference: Fitness versus Fatness in a Population-based Sample of Chilean 8th Graders

Background: In addition to excess adiposity, low cardiorespiratory fitness (CRF) and low musculoskeletal fitness (MSF) are important, independent risk factors for future cardio-metabolic disease in adolescents. To the best of our knowledge the fitness versus fatness relationship has not been studied in a population-based sample in Latin America. Hypothesis: We hypothesized that the physical fitness variables of CRF and MSF will be negatively associated with BMI and WC in an adolescent population in Chile, independent of potential confounders, but that a significant proportion of adolescents with poor body composition will exhibit healthy fitness levels. Methods: This cross-sectional study was based on a representative, single-stage, stratified cluster sample of 19,929 8th graders (median age = 14 years) in the 2011 National Education Survey from all regions of Chile. CRF was assessed with the 20 m shuttle run test, MSF with standing broad jump, and body composition with BMI and WC. CRF, MSF, BMI, and WC were classified according to health-related standards, validated against cardio-metabolic risk factors. Gender-stratified logistic regression models for both CRF and MSF included socioeconomic status, age, region, the other fitness variable, BMI, and WC. Analyses were weighted and considered complex sample design. Results: In both genders, the adjusted prevalence of high-risk CRF was higher among students with high-risk BMI (boys: prevalence ratio (PR) = 1.88; girls: PR = 1.71; both p&lt;0.05) and with high-risk WC (boys: PR = 1.77; girls: PR = 1.21; both p&lt;0.05), compared with their healthy counterparts. BMI but not WC was an independent correlate of high-risk MSF in girls (PR = 1.32; p&lt;0.05). Both BMI (PR=1.64; p&lt;0.05) and WC (PR=1.11; p&lt;0.05) were independent correlates of high-risk MSF in boys. A substantial proportion of students with poor body composition had healthy fitness, and vice versa: 46% of boys and 25% of girls with high-risk BMI had healthy CRF. Conversely, 35% of boys and 55% of girls with high-risk CRF had a healthy BMI. Similarly, 47% of boys and 51% of girls with high-risk BMI had healthy MSF whereas 43% of boys and girls with high-risk MSF had a healthy BMI. Conclusions: In this large representative sample of Chilean adolescents, BMI and WC were inversely correlated with CRF and MSF. Nonetheless, the sizeable proportion of adolescents with poor body composition but healthy fitness, and vice versa, underscores the importance of assessing both CRF and MSF for a more complete representation of adolescent cardio-metabolic risk.

Recommended levels and intensities of physical activity to avoid low‐cardiorespiratory fitness in European adolescents: The HELENA study

The purpose of this study was to determine the sex-specific physical activity (PA) intensity thresholds that best discriminate between unhealthy/healthy cardiorespiratory fitness (CRF). Participants included 1,808 adolescents (964 girls), aged 12.5-17.5 years, from the HELENA study. We measured PA by accelerometer and calculated the time spent at light, moderate, vigorous, and moderate-to-vigorous (MVPA) intensities. CRF was assessed by the 20-m shuttle-run test. Adolescents were dichotomized (unhealthy/healthy) based on sex- and age-specific FITNESSGRAM standards. Receiver operating characteristic (ROC) analysis was used to determine thresholds that best discriminate between CRF categories. ROC analyses revealed that the PA thresholds that best discriminate between unhealthy/healthy CRF were ≥152, ≥33, ≥13, and ≥52 min/day in light, moderate, vigorous, and MVPA, respectively. In boys, the PA thresholds associated with a healthy CRF were ≥37, ≥19, and ≥56 min/day in moderate, vigorous, and MVPA, respectively, whereas in girls were ≥152, ≥34, ≥12, and ≥51 min/day in light, moderate, vigorous, and MVPA, respectively. Spending at least 60 min/day in MVPA was also associated with a healthy CRF (odds ratios: 1.75, 1.94, and 1.57, all P < 0.05, for the whole sample, boys, and girls, respectively). This study shows sex- and intensity-specific PA thresholds to discriminate between adolescents with a healthy CRF from those with a less favorable or unhealthy CRF level.

Secular trends in health-related physical fitness in Spanish adolescents: The AVENA and HELENA Studies

We analysed the secular trends in health-related physical fitness in Spanish adolescents between 2001–2002 and 2006–2007. Two representative population studies were conducted 5 years apart in adolescents (12.5–17.5 years) from Zaragoza (Spain) that participated in the AVENA study in 2001–2002 and in the HELENA-CSS study in 2006–2007. Both studies used the same tests to assess physical fitness: the handgrip strength, bent arm hang, standing broad jump, 4 × 10 m shuttle run and 20 m shuttle run tests. Performance in 4 × 10 m shuttle run and 20 m shuttle run tests was higher in 2006–2007 (Cohen's d ranging from 0.2 to 0.4, p < 0.05), whereas performance in handgrip strength and standing broad jump tests was lower in 2006–2007 (Cohen's d ranging from 0.3 to 1.1, p < 0.001). Adjustment for age, pubertal status, fat mass, fat free mass and parental education did not alter the results. The odds ratio (OR) of meeting the FITNESSGRAM Standards for healthy cardiorespiratory fitness was higher in 2006–2007 in both boys (OR, 95% CI: 2.123, 1.157–3.908) and girls (OR, 95% CI: 2.420, 1.377–4.255). The results indicate that levels of both speed/agility and cardiorespiratory fitness were higher in 2006–2007 than in 2001–2002, whereas muscular strength components were lower in 2006–2007.