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

Associations between cardiorespiratory fitness and executive function in Chinese adolescents

Executive function (EF) has a significant impact on career achievement in adolescence and later adulthood, and there are many factors that influence EF. Cardiorespiratory fitness (CRF) is an important factor in the physical fitness of adolescents and is of great significance to healthy development. However, the current association between CRF and EF in Chinese adolescents is still unclear. For this reason, this study analysed the association between CRF and EF. A three-stage stratified cluster sampling method was used to investigate the demographic information, CRF, EF and multiple covariates of 1245 adolescents in China. One-way analysis of variance and chi-square test were used to compare the EF status of different CRFs. The association between CRF and EF was analysed using multiple linear regression analysis and logistic regression analysis. Multiple linear regression analysis showed that, after adjusting for relevant confounding factors, compared with Chinese adolescents with VO2max < P25, the inhibition function reaction time, 1back reaction time, 2back reaction time, and cognitive flexibility response time of adolescents with VO2max > P75 decreased by 1.41 ms, 238.73 ms, 273.09 ms, 74.14 ms. Logistic regression analysis showed that compared with Chinese adolescents with VO2max > P75, Chinese adolescents with VO2max < P25 developed inhibitory function dysfunction (OR 2.03, 95% CI: 1.29, 3.20), 1back dysfunction (OR 6.26, 95% CI 3.94, 9.97), 2back dysfunction (OR 8.94, 95% CI 5.40, 14.82), cognitive flexibility dysfunction (OR 2.26, 95% CI 1.44, 3.57) The risk was higher (P < 0.01). There is a positive association between CRF and EF in Chinese adolescents. High-grade CRF adolescents have higher EF levels, that is, shorter response times. This study provides reference and lessons for better promoting adolescents' executive function development in the future.

Sex differences in the association between waist circumference and physical fitness index among Tajik adolescents in the Pamir Mountains of Xinjiang, China: an observational study

BACKGROUND

It has been reported in the literature that waist circumference (WC) was related to physical fitness in adolescents. However, the association between WC and PFI(physical fitness index), a comprehensive indicator of physical fitness, has been less studied. In addition, it is not clear whether the association between WC and PFI changes depending on altitude, ethnicity, and sex. This study further revealed the correlation between WC and PFI among adolescents in high-altitude areas and provided references for the physical and healthy development of adolescents in high-altitude areas.

METHODS

In this study, a total of 1705 Tajik adolescents aged 13-15 years were selected using stratified whole-population sampling. WC and physical fitness items (grip strength, standing long jump, 50 m dash, and endurance run) were assessed and a standardized method was used to calculate PFI. The association between WC and PFI was analyzed by curvilinear regression analysis.

RESULTS

The mean and standard deviation of WC and PFI for Tajik adolescents aged 13-15 years old on the Pamir Plateau in Xinjiang, China, were 68.26 ± 7.75 cm and - 2.00 ± 3.47 respectively. Comparison of PFI between groups of Tajik adolescents with different WC showed that inter-group comparisons had significant effects with effect size above 0.2. The Tajik adolescents' PFI reached its highest when WC was 61 cm for boys(-1.3207), and 60 cm for girls (-1.0556).

CONCLUSIONS

The association between WC and PFI in Tajik adolescents showed an inverted "U" curve, with no sex difference. It is recommended that the WC of Tajik adolescents should be controlled between 60 and 61 cm to maintain better PFI levels. The study provides support and reference for educational policy-making and public health prevention in the Pamir Plateau in Xinjiang, China.

Different impacts of physical activity on health in urban and rural older adults

OBJECTIVE

This study aimed to explore the impact of physical activity on health among older adults in urban and rural areas in Taiwan.

METHODS

This study employed a cross-sectional design and data were analyzed from 2015 to 2019 from the Hualien County Health Bureau. Participants were divided into urban (n = 4780) and rural groups (n = 4983), and logistic regression models were employed to examine how physical activity relates to their health condition in urban and rural older adults.

RESULTS

Results indicated lower physical activity levels and higher unhealthy behavior rate in rural older adults compared to their urban counterparts. Rural older adults had higher rates of cardiovascular diseases and diabetes but lower rates of mental illness. Physical activity demonstrated greater physical health benefits for urban older adults than rural older people. Conversely, rural individuals who engaged in physical activity 150 min/week exhibited greater mental health benefits than their urban counterparts.

CONCLUSIONS

Physical activity offers significant mental health benefits for both urban and rural older adults; however, notable improvements in physical health among urban older adults was found. If in the presence of unhealthy behaviors, regular physical activity may not effectively prevent chronic diseases. It is crucial to promote physical activity and healthy behaviors in rural areas.

Prevention of cardiotoxicity in childhood cancer survivors: In physical exercise, we trust

In recent years, the mean survival rate of children after a cancer diagnosis has significantly improved. At the same time, a growing interest in short and long-term cardiovascular (CV) complications of cancer therapy, as well as long-term CV risk in childhood cancer survivors (CCS) developed, along with proposals of protocols for the diagnosis, management, and prevention of cancer therapy-related CV toxicity (CTR-CVT) in this population. Many clinical and individual risk factors for CTR-CVT have been identified, and a non-negligible prevalence of traditional CV risk factors has been described in this population, potentially associated with a further worsening in both CTR-CVT and long-term CV risk. Physical exercise (PE) represents a promising, free-of-cost and free-of-complications, helpful therapy for primary and secondary prevention of CTR-CVT in CCS. The present narrative review aims to summarize the most critical evidence available about CTR-CVT in CCS, focusing on the role of PE in this clinical scenario.

Factors affecting maximal oxygen uptake in prepubertal children: a systematic review and meta-analysis

In pre-pubertal children the factors affecting maximal oxygen uptake have yet to be fully understood. Therefore, the purpose of this analysis is to present cardiorespiratory fitness in prepubertal boys and girls and to determine if there are any differences based on sex, exercise testing modality or if maximal or peak oxygen consumption metrics are used. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. For statistical analysis, multilevel models grounded in Bayesian principles were used. Selected studies obtained: maximal effort during the test, peak or maximal oxygen consumption (V̇O2) values, boys and girls (sex specific groups only) age under 11, cycle ergometry or treadmill, pre-intervention or no intervention data. In boys using cycle ergometry, 118 studies were included in the analysis, in boys using treadmill 115, in girls using cycle ergometry 83 and in girls using treadmill testing 95 study entries were included. As children get older, their cardiorespiratory fitness increases (P ≈ 100%). Studies with participants having smaller body mass have higher V̇O2 relative to body mass values (P ≈ 100%). Boys have higher V̇O2 values than girls (P ≈ 100%). Studies using treadmill reported higher values than those using cycle ergometer (P ≈ 100%). Regarding the influence of measurement method (max vs. peak) on V̇O2 values we did not find significant differences. In conclusion, we present reference values for cardiorespiratory fitness in prepubertal boys and girls using cycle ergometry or treadmill. Prepubertal boys have higher cardiorespiratory fitness than girls and using treadmill testing might be a preferred method to cycle ergometry, especially in older children. Maximal or peak oxygen consumption metrics might be used interchangeably in prepubertal children.

Isotemporal Substitution Effects of Daily Time Use on Cardiorespiratory Fitness of Children in the OptiChild Study: A Mediation Analysis with Diet Quality

(1) Background: Although daily time-use is associated with diet quality and cardiorespiratory fitness (CRF) in children, their interdependence remains unexplored. This study first examined the associations between reallocating daily movement time and diet quality and CRF, and second the mediating role of diet quality in the relationship between daily time-use and CRF. (2) Methods: This study included 1131 Chinese children (aged 8 to 10 years; median [interquartile range]: 8.5 [8.3, 8.8]) at baseline (September 2022) and 1268 children at the 9-month follow-up (June 2023) from the OptiChild study. Daily durations of moderate-to-vigorous physical activity (MVPA), sleep, and sedentary behavior (e.g., screen time) were self-reported or proxy-reported by parents. Diet quality was assessed via the Diet Quality Questionnaire (DQQ), which uses a 24 h dietary recall and is categorized according to the Global Dietary Recommendations (GDR) score and Food Group Diversity Score (FGDS). The CRF was measured using VO2max after the 20 m shuttle run test. Longitudinal associations between daily time-use, diet quality, and CRF were calculated using isotemporal substitution models. Mediation analyses were used to determine whether diet quality mediated the associations between daily time-use and CRF. (3) Results: Reallocation of 30 min from screen time to MVPA resulted in significant improvements in the GDR score (β baseline = 0.11, p = 0.024; β follow-up = 0.26, p < 0.001), FGDS (β baseline = 0.11, p = 0.006; β follow-up = 0.19, p < 0.001), and CRF (β baseline = 0.40, p < 0.001; β follow-up = 0.26, p = 0.001). Diet quality partially mediated the associations between MVPA, screen time, and CRF. Substituting 30 min of screen time for MVPA led to diet quality mediating a proportion of the association with CRF (GDR score: 11.4%, FGDS: 6.6%). (4) Conclusions: These findings underscore the importance of optimizing daily time-use of MVPA and screen time and improving diet quality to promote physical fitness in school-aged children.

Cross-country adaptation and feasibility of an evidence-based resistance training intervention in the school setting

Background

Physical activity that strengthens muscles and bones at least three times per week are recommended, but few adolescents meet this target. The aim of our study was to adapt and evaluate the feasibility and preliminary efficacy of the Resistance Training for Teens (RT4T) program in Danish lower secondary schools.

Methods

Developed and evaluated in Australia, the aim of RT4T is to provide adolescents with competence, confidence, knowledge, and motivation to participate in resistance training. Translation and adaptation were based on the PRACTIS-guide and involved workshops with physical education teachers. Three 7th-grade classes and three 9th-grade classes were recruited for the feasibility study and followed the program over eight weeks. Participants completed a push-up test, a standing long jump test, and a beep-test before and after the intervention. In addition, they completed a survey about their self-efficacy, motivation, and resistance training competency. Four qualitative interviews were performed with participants and their physical education teachers.

Results

The participating teachers were motivated for the program, but they had difficulties providing students with appropriate feedback. Students were motivated by the equipment, games, and their improvements in fitness, but motivation declined during the program. A total of 57 students completed the physical tests and answered the survey. Resistance training self-efficacy improved significantly, while most other measures improved over time, without reaching significance.

Conclusion

Overall, the RT4T was acceptable and feasible in lower secondary schools in Denmark, but adjustments need to be made to increase the reach and efficacy of the program.

Development of a Pediatric Cardiology Cardiopulmonary Exercise Testing Database

Cardiopulmonary exercise testing (CPET) provides clinicians with information vital to the management of pediatric cardiology patients. CPET can also be used to measure cardiorespiratory fitness (CRF) in these patients. CRF is a robust marker of overall health in children. However, a complete understanding of CRF in pediatric cardiology patients is limited by lack of large, standardized CPET databases. Our purpose was to develop a standardized CPET database, describe available data at our institution, and discuss challenges and opportunities associated with this project. CPETs performed from 1993 to present in an urban pediatric hospital were collected and compiled into a research database. Historical data included demographic and clinical variables and CPET outcomes, and additional variables were calculated and coded to facilitate analyses in these cohorts. Patient diagnoses were coded to facilitate sub-analyses of specific cohorts. Quality assurance protocols were established to ensure future database contributions and promote inter-institutional collaborations. This database includes 10,319 CPETs (56.1% male), predominantly using the Bruce Protocol. Patients ranging from ages 6 to 18 years comprise 86.8% of available CPETs. Diagnosis classification scheme includes patients with structurally normal hearts (n = 3,454), congenital heart disease (n = 3,614), electrophysiological abnormalities (n = 2,082), heart transplant or cardiomyopathy (n = 833), and other diagnoses (n = 336). Historically, clinicians were provided with suboptimal interpretive resources for CPET, often generalizing inferences from these resources to non-representative clinical populations. This database supports representative CRF comparisons and establishes a framework for future CRF-based registries in pediatric patients referred for CPET, ultimately improving clinical decision-making regarding fitness in these populations.

Using cardiorespiratory fitness to operationalize vitality: a path analysis on the hierarchical structure of intrinsic capacity

BACKGROUND

There is a lack of consensus about the operationalization of vitality, which is one of the intrinsic capacity (IC) domains. In particular, no study has investigated whether cardiorespiratory fitness (CRF) can be considered a vitality indicator.

OBJECTIVE

To examine whether vitality is the upstream domain of IC, and establish the validity of CRF as a vitality indicator, using maximal oxygen consumption (VO2 max) as a representative.

METHODS

561 older adults from a longitudinal cohort study were included. Variables under consideration were VO2 max, other IC domains, instrumental activities of daily living (IADL), and handgrip strength, which was considered an already validated indicator of vitality. Using handgrip strength as the reference point, path analyses were performed to examine whether VO2 max followed a similar hierarchical structure in predicting change in IADL difficulty through other IC domains.

RESULTS

The mean age of the participants was 75.5 years. The path model in which vitality was measured by VO2 max demonstrated adequate fit, which was similar to the model in which vitality was measured by handgrip strength. Regarding the path coefficients, the model using VO2 max demonstrated significant total and indirect effects. Notably, the indirect effect was due to the locomotor domain (standardized coefficient = -0.148, p < .001), but not the cognitive or psychological domain.

CONCLUSION

Vitality is the upstream domain of IC. VO2 max can be considered an indicator to operationalize the vitality concept.

Longitudinal Patterns of Systolic Blood Pressure, Diastolic Blood Pressure, Cardiorespiratory Fitness, and Their Association With Dementia Risk: The HUNT Study

BACKGROUND

High blood pressure and poor cardiorespiratory fitness are independent risk factors for dementia. However, few studies have examined if combined longitudinal patterns of these modifiable risk factors are associated with dementia risk.

METHODS

In this prospective cohort study, we used data from the population-based Trøndelag Health (HUNT) Study, Norway. We applied group-based multidimensional trajectory modeling to identify age-specific multidimensional trajectories of SBP, DBP, and estimated cardiorespiratory fitness across 3 surveys (HUNT1, 1984-1986 to HUNT3, 2006-2008). Dementia was diagnosed in the HUNT4 70+ substudy in 2017-2019. We used multivariate logistic regression to estimate odds ratios (ORs) and risk differences (RDs) of dementia.

RESULTS

In total, 7 594 participants (54.9% women) were included, with a mean age of 44.7 (SD 6.3) years at HUNT1. Dementia was diagnosed in 1 062 (14.0%) participants. We identified 2 multidimensional trajectories throughout adulthood within 3 age groups: one with higher systolic blood pressure (SBP) and diastolic blood pressure (DBP), and lower estimated cardiorespiratory fitness (the poorer group), and one with lower SBP and DBP, and higher cardiorespiratory fitness (the better group). After adjustment for sex, apolipoprotein E ε4 status, education, marital status, and diabetes, the better group had consistently lower risk of dementia in all age groups with the lowest OR in the middle-aged group of 0.63 (95% confidence intervals [95% CI]: 0.51, 0.78) with corresponding RD of -0.07 (95% CI: -0.10, -0.04).

CONCLUSIONS

Having a beneficial multidimensional trajectory of SBP, DBP, and cardiorespiratory fitness in adulthood was associated with reduced dementia risk. Aiming for optimal SBP, DBP, and estimated cardiorespiratory fitness throughout adulthood may reduce dementia risk.

Assessing the Accuracy of Smartwatch-Based Estimation of Maximum Oxygen Uptake Using the Apple Watch Series 7: Validation Study

BACKGROUND

Determining maximum oxygen uptake (VO2max) is essential for evaluating cardiorespiratory fitness. While laboratory-based testing is considered the gold standard, sports watches or fitness trackers offer a convenient alternative. However, despite the high number of wrist-worn devices, there is a lack of scientific validation for VO2max estimation outside the laboratory setting.

OBJECTIVE

This study aims to compare the Apple Watch Series 7's performance against the gold standard in VO2max estimation and Apple's validation findings.

METHODS

A total of 19 participants (7 female and 12 male), aged 18 to 63 (mean 28.42, SD 11.43) years were included in the validation study. VO2max for all participants was determined in a controlled laboratory environment using a metabolic gas analyzer. Thereby, they completed a graded exercise test on a cycle ergometer until reaching subjective exhaustion. This value was then compared with the estimated VO2max value from the Apple Watch, which was calculated after wearing the watch for at least 2 consecutive days and measured directly after an outdoor running test.

RESULTS

The measured VO2max (mean 45.88, SD 9.42 mL/kg/minute) in the laboratory setting was significantly higher than the predicted VO2max (mean 41.37, SD 6.5 mL/kg/minute) from the Apple Watch (t18=2.51; P=.01) with a medium effect size (Hedges g=0.53). The Bland-Altman analysis revealed a good overall agreement between both measurements. However, the intraclass correlation coefficient ICC(2,1)=0.47 (95% CI 0.06-0.75) indicated poor reliability. The mean absolute percentage error between the predicted and the actual VO2max was 15.79%, while the root mean square error was 8.85 mL/kg/minute. The analysis further revealed higher accuracy when focusing on participants with good fitness levels (mean absolute percentage error=14.59%; root-mean-square error=7.22 ml/kg/minute; ICC(2,1)=0.60 95% CI 0.09-0.87).

CONCLUSIONS

Similar to other smartwatches, the Apple Watch also overestimates or underestimates the VO2max in individuals with poor or excellent fitness levels, respectively. Assessing the accuracy and reliability of the Apple Watch's VO2max estimation is crucial for determining its suitability as an alternative to laboratory testing. The findings of this study will apprise researchers, physical training professionals, and end users of wearable technology, thereby enhancing the knowledge base and practical application of such devices in assessing cardiorespiratory fitness parameters.

The associations between organized sport participation and physical fitness and weight status development during adolescence

OBJECTIVES

We are yet to understand how continuous participation in organized sports, dropout from organized sports, or complete non-participation affect adolescents' trajectories of physical fitness and body mass index (BMI). Thus, the aim was to examine longitudinal changes in cardiorespiratory and muscular fitness, and BMI between adolescents 1) who continued or started organized sport participation, 2) who dropped out, and 3) who never participated in organized sport or dropped out before adolescence.

DESIGN

Longitudinal observational study.

METHODS

Over four years (2017-2021), sport participation, cardiorespiratory and muscular fitness, and BMI data were collected annually from 963 participants (Mage = 11.25 ± 0.31). Latent growth curve models were utilized to examine levels (baseline) and slopes (rate of change) of BMI, cardiorespiratory, and muscular fitness in each sport participation group.

RESULTS

Fitness levels significantly varied among groups. Continuing sport participants exhibited the highest levels, non-participants the lowest. Both groups showed significant improvements in cardiorespiratory and muscular fitness over time. Dropouts had higher baseline fitness than non-participants but demonstrated no change in cardiorespiratory fitness over time and a significantly smaller increase in muscular fitness than the two other groups. BMI increased similarly in all groups, with non-participants starting at higher baseline levels.

CONCLUSIONS

Individuals who continually participated in sports maintained higher levels of fitness than individuals who did not participate in organized sports across adolescence. However, individuals who dropped out of organized sports, showed plateau in their fitness improvements, suggesting that the physical activity previously obtained through organized sports may not be replaced elsewhere.

The Cardiorespiratory Fitness of Children and the Anthropometric Determinants During Late Childhood Within South East Wales: Potential Implications for Future Health

Objective. This study investigated cardiorespiratory fitness (CRF) levels and the relationship with field-based measures of anthropometry in children aged 10 to 11 years. Methods. A total of 288 boys and 257 girls participated in the study. CRF (20 m shuttle run) and several field-based measures of anthropometry were assessed. Multiple regression was utilized for all data analysis. Results. Boys performed significantly better than girls on the CRF test (P < .001) and achieved higher classifications of CRF based on centile norms compared to girls. All measures of anthropometry were significant predictors of CRF, (P < .001), and each measure was significant in predicting a negative trajectory of CRF performance when they increased in value (P < .05). Conclusion. The study findings add to the international reporting of CRF and the use of simple field-based measures of anthropometry alongside the use of BMI to predict CRF for health with Welsh school children (UK).

The Mediating Role of Cardiorespiratory Fitness in the Association between a Negative Lifestyle and Poor Mental Health in Chilean Schoolchildren

BACKGROUND

A negative lifestyle has a reported relationship with psychological problems and deteriorated well-being. However, there is little information regarding the mediating role of cardiorespiratory fitness (CRF) in this relationship.

OBJECTIVES

The objectives of the present study are twofold: first, to investigate the association between negative lifestyle, physical self-concept (PSC), and depression, and second, to assess the potential mediating role of CRF in this complex relationship.

METHODS

This cross-sectional study included 612 schoolchildren aged between 9 and 14 years from the Araucanía region (southern Chile). CRF was measured using the Leger test, and lifestyle, depression, and PSC were measured using validated questionnaires.

RESULTS

A negative lifestyle reported an inverse association with PSC (p < 0.001) and a positive association with depression levels (p < 0.001). The mediation analysis showed that CRF was positively related to PSC (p < 0.001) and inversely related to depression (p = 0.001); besides, the indirect effect CRF acted as a partial mediator in the association between a negative lifestyle and PSC (indirect effect = -1.15; SE = 0.01; 95% CI, -1.87, -0.55) and depression levels (indirect effect = 0.22; SE = 0.08; 95% CI, 0.08, 0.38).

CONCLUSION

In conclusion, CRF in schoolchildren played a potential mediating role in the association between a negative lifestyle and depression and PSC.

Association between Depressive Symptoms, Physical Activity, and Health Factors in Hispanic Emerging Adults

Physical activity is a modifiable lifestyle behavior known for reducing symptoms of and being a risk factor for depression and mental health disorders. However, emerging adults (ages 18-25) struggle to meet recommended amounts. In this study, we explore the association between physical activity, depressive symptoms, and health factors in 137 Hispanic emerging adults. Using a cross-sectional survey design, sociodemographic information, depressive symptoms (CES-D score), physical activity (IPAQ score), body composition, and blood pressure measures were obtained. Statistical analyses included correlation and regression analyses. More than half of the participants demonstrated depressive symptomology (59.1%) and body fat percentage greater than 25% (64.2%). Body fat percentage, lean body mass, stress, and heart rate demonstrated notable associations with depressive symptoms and physical activity. When measured continuously and categorically, IPAQ was not a significant predictor of depressive symptoms. When used as a binary variable with a cutoff of 600 MET min/week, IPAQ score revealed a negative relationship with CES-D score (β = -0.169, SE = 2.748, p = 0.034). Our results indicate that a threshold of physical activity, 600 MET min/week, may confer protective effects against depressive symptoms. Future research should investigate the context and quality of physical activity to address mental health disparities in this underrepresented population.

Cardiac rehabilitation in children and adolescents with long QT syndrome: the RYTHMO'FIT pilot study

BACKGROUND

To assess the feasibility, acceptability, safety, and short-term benefits of a tailored cardiac rehabilitation program for children and adolescents with long QT syndrome (LQTS).

METHODS

Eight participants, aged between 6 and 18, with a positive LQTS genotype and impaired cardiorespiratory fitness, were enrolled in a 12-week centre-based cardiac rehabilitation program. The program included supervised exercise training group sessions (aerobic, resistance, and outdoor activities) and patient education workshops. Feasibility, acceptability, and safety of the program were prospectively monitored. Feedback from the parents, children, and professionals involved was collected from qualitative interviews. Short-term effects on cardiorespiratory fitness, muscle fitness, physical activity, and health-related quality of life (HRQoL) were measured between baseline and the end of the program.

RESULTS

Retention (88% with one participant dropping out) and adherence (79%) rates were good, and no cardiac events occurred during the 12-week intervention period. Participants, parents, and healthcare professionals expressed a high level of satisfaction with the program. A significant increase between the beginning and the end of the program was observed for ventilatory anaerobic threshold (21.7±5.2 vs. 28.7±5.1 mL/kg/min, P=0.01, effect size=0.89), grip strength, (18±5.3 Kg vs. 20±4.7 Kg, P=0.02, effect size=0.90), lower limb explosive strength (142±36.5 cm vs. 148±24 cm, P=0.02, effect size=0.90), and parent-reported physical health dimension of HRQoL (65.6±9.75 vs. 84.4±20.35, P=0.03, effect size=0.87).

CONCLUSIONS

A 12-week tailored centre-based cardiac rehabilitation program was feasible, acceptable, and safe for children with LQTS. Cardiac rehabilitation for children with LQTS presents a new approach aligned with secondary prevention in youth with cardiac diseases.

TRIAL REGISTRATION

The trial was registered at Clinicaltrials.gov (NCT05964322, registration date: 27/07/2023).

Adolescent Cardiorespiratory Fitness and Risk of Cancer in Late Adulthood: Nationwide Sibling-Controlled Cohort Study

Objective

To investigate whether the higher risks of certain cancers associated with high cardiorespiratory fitness can be explained by increased detection and unobserved confounders.

Design

Nationwide sibling-controlled cohort study of adolescents.

Setting

Sweden.

Participants

1 124 049 men of which 477 453 were full siblings, who underwent mandatory military conscription examinations between 1972 and 1995 at a mean age of 18.3 years.

Main outcome measures

Hazard ratios (HR) and 95% confidence intervals (CI) of overall cancer diagnosis and cancer mortality, and 14 site-specific cancers (diagnosis or death), as recorded in the Swedish National Patient Register or Cause of Death Register until 31 December 2023, modelled using flexible parametric regressions.

Results

Participants were followed until a median (maximum) age of 55.9 (73.5) years, during which 98 410 were diagnosed with cancer and 16 789 had a cancer-related death (41 293 and 6908 among full siblings respectively). The most common cancers were non-melanoma skin (27 105 diagnoses & 227 deaths) and prostate cancer (24 211 diagnoses & 869 deaths). In cohort analysis, those in the highest quartile of cardiorespiratory fitness had a higher risk of prostate (adjusted HR 1.10; 95% CI: 1.05 to 1.16) and skin cancer (e.g., non-melanoma HR 1.44; 1.37 to 1.50) compared to those in the lowest quartile, which led to a higher risk of any type of cancer diagnosis (HR 1.08; 1.06 to 1.11). However, those in the highest quartile had a lower risk of cancer mortality (HR 0.71; 0.67 to 0.76). When comparing full siblings, and thereby controlling for all behavioural, environmental, and genetic factors they share, the excess risk of prostate (HR 1.01; 0.90 to 1.13) and skin cancer (e.g., non-melanoma HR 1.09; 0.99 to 1.20) attenuated to the null. In contrast, the lower risk of overall cancer mortality was still statistically significant after control for such shared confounders (HR 0.78; 0.68 to 0.89). For other site-specific cancers, the influence of such confounding tended to vary, but none showed the same excess risk as prostate and non-melanoma skin cancer.

Conclusions

The association between high levels of adolescent cardiorespiratory fitness and excess risk of some cancers, such as prostate and non-melanoma skin cancer, appears to be fully explained by unobserved confounders shared between full siblings. However, the protective association with cancer mortality persists even after control for such confounding.

Individual and school correlates of body mass index and cardiorespiratory fitness in primary school children from the REACT project: A multivariate multilevel analysis

OBJECTIVE

This paper examines the relationship between body mass index (BMI) and cardiorespiratory fitness (CRF) using a multivariate multilevel approach and investigates the links between individual and school-related correlates with children's BMI and CRF.

METHODS

This cross-sectional sample included 1014 children (6-10 years) from 25 Portuguese primary schools. BMI was calculated, and CRF was assessed with the PACER test. Fundamental movement skills (FMS) included five object control tasks. Moderate-to-vigorous physical activity (MVPA), sleep, and sedentary time were assessed with the ActiGraph wGT3X-BT accelerometer. Socioeconomic status (SES) and school variables were also obtained. A multivariate multilevel model was used, and alpha was set at 5%.

RESULTS

BMI and CRF systematically increased with age. Most of the joint variance (94.4%) was explained at the child level, and BMI and CRF were correlated at this level (ρ = -.37). More active children demonstrated higher CRF levels and had lower BMI levels; sedentary and sleep time were not significantly associated with BMI or CRF. FMS were positively associated with CRF but were not significantly associated with BMI. Children at higher SES were more fit and had lower BMI than their peers of lower SES. Finally, school-level variables were not significantly related to BMI and CRF.

CONCLUSION

BMI and CRF had a low but statistically significant negative correlation in this sample of children. Most of the variation in BMI and CRF was explained by child-level characteristics.

Cardiorespiratory fitness and muscular fitness correlates in youth: A hierarchy of behavioral, contextual, and health-related outcomes

OBJECTIVES

Despite the health importance of identifying correlates of physical fitness in youth, no investigation to date has explored the influence of behavioral, health-related, and contextual correlates simultaneously. We investigated the hierarchical relationship of multiple modifiable correlates favoring or diminishing cardiorespiratory and muscular fitness in youth.

DESIGN

Cross-sectional investigation.

METHODS

In a sample of 5174 children and adolescents, 31 correlates were hierarchized according to their impact on cardiorespiratory and muscular fitness assessed using the FITESCOLA® fitness battery. A Chi-squared Automatic Interaction Detection approach was employed and measures of correlation and association were used to investigate the relationship between physical fitness and correlates.

RESULTS

In children, body mass index was the most relevant factor to discriminate between high and low cardiorespiratory and muscular fitness of the upper, middle, and lower body. While body mass index was more important than any other correlate to differentiate levels of upper and lower body muscular fitness during adolescence, specific characteristics of sports participation emerged as key factors to discriminate between high and low cardiorespiratory fitness and middle body muscular fitness. Other correlates, including the self-report of active recess time, active commuting to school, favorable neighborhood conditions, and limited time on screens and cellphones, were demonstrative of favorable physical fitness levels.

CONCLUSIONS

Both body composition and sports-related characteristics emerged as the two most relevant factors of physical fitness in youth. Additional health benefits may be obtained from building supportive environments for sports and healthy exercise habits within the household and at different school education levels.

Associations Between Neighborhood Opportunity and Indicators of Physical Fitness for New York City Public School Youth

Background: Fewer than 1/4th of US children and adolescents meet physical activity (PA) guidelines, leading to health disparities that track into adulthood. Neighborhood opportunity may serve as a critical modifiable factor to improve fitness attainment and reduce these disparities. We drew data from the Child Opportunity Index to examine associations between neighborhood indicators of opportunity for PA and multiple fitness indicators among New York City public school youth. Methods: Multilevel generalized linear mixed models were used to estimate the overall and sex-stratified associations between neighborhood indicators (green space, healthy food, walkability, commute time) and indicators for physical fitness [curl-ups, push-ups, Progressive Aerobic Cardiovascular Endurance Run (PACER), sit-and-reach] using the New York City FITNESSGRAM data set. Results: The analytic sample [n = 299,839; median (interquartile range) age = 16 (12-17)] was 50.1% female, 37.5% Hispanic, 26.2% non-Hispanic Black, and most (69.5%) qualified for free/reduced price school meals. Neighborhood indicators were positively associated with higher values of indicators for physical fitness. The strongest associations were observed between walkability and both BMI and PACER, and commute time with BMI, push-ups, and PACER. For example, walkability had the greatest magnitude of effects for BMI and muscular strength and endurance (BMI: β: -0.75, 95% confidence interval, CI: -1.01 to -0.49; PACER: β: 1.98, 95% CI: 1.59 to 2.37), and particularly for girls compared with boys (BMI, girls: β: -0.91, 95% CI: -1.22 to -0.66); BMI, boys: β: -0.56, 95% CI: -0.86 to -0.25); PACER, girls: β: 2.11, 95% CI: 1.68 to 2.54; push-ups, boys: β: 1.71, 95% CI: 1.31 to 2.12). Conclusion: Neighborhood indicators were associated with multiple measures of youth fitness. Continued research on neighborhood opportunity and youth fitness may better inform place-based public health interventions to reduce disparities.

Determinants of cardiorespiratory fitness measured by cardiopulmonary exercise testing in COVID-19 survivors: a systematic review with meta-analysis and meta‑regression

BACKGROUND

The relationship between cardiorespiratory fitness and its possible determinants in post-COVID-19 survivors has not been systematically assessed.

OBJECTIVES

To identify and summarize studies comparing cardiorespiratory fitness measured by cardiopulmonary exercise testing in COVID-19 survivors versus non-COVID-19 controls, as well as to determine the influence of potential moderating factors.

METHODS

We conducted a systematic search of MEDLINE/PubMed, Cochrane Library, EMBASE, Google Scholar, and SciELO since their inceptions until June 2022. Mean differences (MD), standard mean differences (SMD), and 95% confidence intervals (CI) were calculated. Subgroup and meta-regression analyses were used to evaluate potential moderating factors.

RESULTS

48 studies (3372 participants, mean age 42 years, and with a mean testing time of 4 months post-COVID-19) were included, comprising a total of 1823 COVID-19 survivors and 1549 non-COVID-19 controls. After data pooling, VO2 peak (SMD=1.0 95% CI: 0.5, 1.5; 17 studies; N = 1273) was impaired in COVID-19 survivors. In 15 studies that reported VO2 peak values in mL/min/kg, non-COVID-19 controls had higher peak VO2 values than COVID-19 survivors (MD=6.2, 95% CI: 3.5, 8.8; N = 905; I2=84%). In addition, VO2 peak was associated with age, time post-COVID-19, disease severity, presence of dyspnea, and reduced exercise capacity.

CONCLUSION

This systematic review provides evidence that cardiorespiratory fitness may be impaired in COVID-19 survivors, especially for those with severe disease, presence of dyspnea, and reduced exercise capacity. Furthermore, the degree of reduction of VO2 peak is inversely associated with age and time post-COVID.

KidsTUMove-A Holistic Program for Children with Chronic Diseases, Increasing Physical Activity and Mental Health

The prevalence of chronic diseases in children and adolescents has risen alarmingly worldwide. Diseases such as asthma, diabetes, obesity, mental disorders, and congenital heart defects are increasingly affecting the lives of children and pose significant challenges for the healthcare system. Physical activity plays a crucial role in preventing and treating these diseases. Numerous studies have shown that regular exercise improves physical performance, increases well-being, and leads to better health in the long term. Specially tailored sports programs that meet the individual needs and abilities of the children and adolescents affected are particularly important. The KidsTUMove project addresses this by developing tailored exercise programs for children with chronic diseases' specific needs, medical conditions, and physical abilities. Therefore, it closes the gap in care provision and can thus sustainably improve the health prospects of these children and adolescents. KidsTUMove is positioned to make a significant impact on the lives of affected children across Europe. Promotion of such programs should therefore be an integral part of future health strategies.

Associations of Cardiorespiratory Fitness and Muscular Endurance Fitness With Pulmonary Function in Physically Active Young Adults

RATIONALE

While the beneficial effects of physical fitness on general health are well-documented, the specific relationship between different types of physical fitness, particularly cardiorespiratory fitness (CRF) and muscular endurance fitness (MEF), and lung function in physically active young adults remains less explored.

OBJECTIVE

This study investigated the relationship between CRF and MEF, and their correlation with lung function in physically active young adults.

METHODS

This cross-sectional study involved a cohort of 1227 physically active young adults without lung diseases. Lung function was assessed using FEV1, FVC, and FEV1/FVC measurements. The 3000-m run was used to assess CRF, and the 2-min push-up and sit-up tests were used to assess MEF. Multivariable linear regression analysis was used to evaluate the relationships between these fitness measures and lung function, adjusting for potential covariates.

RESULTS

Enhanced CRF was associated with superior FEV1 and FVC after adjusting for covariates (β=-.078, p=.015 for FEV1; β=-.086, p=.009 for FVC). Push-ups were positively associated with FEV1 (β=.102, p=.014), but not with FVC. In contrast, sit-ups showed no significant correlation with lung function in the fully adjusted model.

CONCLUSION

The study demonstrated a clear association between improved physical fitness and better lung function in physically active young adults, with various exercises showing distinct associations with lung metrics. Notably, push-ups were particularly associated with higher FEV1. A future prospective study is necessary to determine whether routine exercises, such as push-ups, might lead to greater lung function.

A Novel Summer Camp Integrating Physical, Psychological, and Educational Health in Youth: The THINK Program

Numerous youth summer programs focus upon physical fitness, nutritional health, psychological well-being, or education. Few, however, have integrated all of these elements into a single program. The Translational Health in Nutrition and Kinesiology (THINK) program provides an integrative nutrition and exercise science curriculum that is interfaced with social emotional learning (SEL) and STEM education to enhance healthy behaviors in youth. The purpose of this study was to determine whether the THINK program could improve physical fitness, nutrition habits, SEL, and STEM education in a 6-week summer program covering a 3-year period. Participants from South Miami were enrolled in THINK (n = 108, 58 males, 50 females, 12.03 + 0.56 years). Physical fitness assessments, the Positive Youth Development Inventory (PYDI), the Students' Attitude Towards STEM Survey, and the Adolescent Food Habits Checklist (ADFH) were recorded at baseline and post-testing. Means and standard error values were evaluated for all dependent variables. Paired samples t-tests (SPSS version 27) were used to determine changes. Improvements in cardiorespiratory fitness (p < 0.001), power (p < 0.006), flexibility (p < 0.001), agility (p < 0.001), muscular endurance (p < 0.001), lean body mass (p < 0.001), ADFH (p < 0.001), and PYDI (p = 0.038) were found. An integrative summer fitness program can result in improvements in physical fitness, nutrition habits, and SEL in as little as six weeks.

Practical Aspects of Cardiopulmonary Exercise Testing in Children

The use of cardiopulmonary exercise testing (CPET) in pediatrics provides critical insights into potential physiological causes of unexplained exercise-related complaints or symptoms, as well as specific pathophysiological patterns based on physiological responses or abnormalities. Furthermore, CPET helps evaluate exercise performance in children with chronic (lung/heart) diseases. For instance, it can ascertain any adverse reaction to exercise and estimate the effects of specific treatment measures. It affords a global assessment of the pathophysiological patterns, responses and abnormalities to exercise that is inadequately reflected by resting lung function and/or cardiac function assessment. Clinical interpretation of the results of a CPET in pediatrics requires specific knowledge regarding pathophysiological responses and interpretative strategies that can be adapted to address concerns specific to the child's medical condition or disability.

Physical Fitness and Risk of Mental Disorders in Children and Adolescents

Importance

With the rising prevalence of mental disorders among children and adolescents, identifying modifiable associations is critical.

Objective

To examine the association between physical fitness and mental disorder risks.

Design, Setting, and Participants

This nationwide cohort study used data from the Taiwan National Student Fitness Tests and National Health Insurance Research Databases from January 1, 2009 to December 31, 2019. Participants were divided into 2 cohorts targeting anxiety and depression (1 996 633 participants) and attention-deficit/hyperactivity disorder (ADHD; 1 920 596 participants). Participants were aged 10 to 11 years at study entry and followed up for at least 3 years, had a nearly equal gender distribution, and an average follow-up of 6 years. Data were analyzed from October 2022 to February 2024.

Exposures

Assessments of physical fitness included cardiorespiratory fitness (CF), muscular endurance (ME), muscular power (MP), and flexibility, measured through an 800-m run time, bent-leg curl-ups, standing broad jump, and sit-and-reach test, respectively.

Main Outcomes and Measures

Kaplan-Meier method calculated the cumulative incidence of anxiety, depression, and ADHD across fitness quartiles. Additionally, multivariable Cox proportional hazards models were used that included all 4 fitness components and explored sex and income as modifiers.

Results

The anxiety and depression cohort had 1 996 633 participants (1 035 411 participants were male [51.9%], and the median [IQR] age was 10.6 [10.3-11.0] years), while the ADHD cohort had 1 920 596 (975 568 participants were male [51.9%], and the median [IQR] age was 10.6 [10.3-11.0] years). Cumulative incidence of mental disorders was lower among participants in better-performing fitness quartiles, suggesting a dose-dependent association. Gender-specific analyses, controlling for confounders, revealed that improved CF, indicated by a 30-second decrease in run times, was associated with reduced risks of anxiety, depression, and ADHD in female participants, and lower risks of anxiety and ADHD in male participants (adjusted hazard ratio [aHR] for ADHD risk for female participants, 0.92; 95% CI, 0.90-0.94; P < .001; for male participants, 0.93; 95% CI, 0.92-0.94; P < .001). Enhanced ME, marked by an increase of 5 curl-ups per minute, was associated with decreased risks of depression and ADHD in female participants, and lower anxiety and ADHD risks in male participants (aHR for ADHD risk for female participants, 0.94; 95% CI, 0.92-0.97; P < .001; for male participants, 0.96; 95% CI, 0.95-0.97; P < .001). Improved MP, reflected by a 20-cm increase in jump distance, was associated with reduced risks of anxiety and ADHD in female participants and reduced anxiety, depression, and ADHD in male participants (aHR for ADHD risk for female participants, 0.95; 95% CI, 0.91-1.00; P = .04; for male participants, 0.96; 95% CI, 0.94-0.99; P = .001).

Conclusions and Relevance

This study highlights the potential protective role of cardiorespiratory fitness, muscular endurance, and muscular power in preventing the onset of mental disorders. It warrants further investigation of the effectiveness of physical fitness programs as a preventive measure for mental disorders among children and adolescents.

Longitudinal Associations Between Enjoyment of Physical Education, Cardiorespiratory Fitness, and Muscular Fitness Among Finnish Adolescents

INTRODUCTION

Students' experiences in physical education (PE) can shape future physical activity (PA) behaviors. PE enjoyment is associated with PA; however, the relationship between PE enjoyment and fitness has not been extensively investigated. The aim of this study was to examine if changes in PE enjoyment were associated with changes in cardiorespiratory fitness (CRF) and muscular fitness (MF) among Finnish adolescents.

METHODS

Study participants were students (n = 1147; 11.27 [±0.32] years at baseline) attending public schools in Finland. Data were collected yearly (2017-2021). The 20 m shuttle run assessed CRF, curl-up/push-up tests assessed MF, and the enjoyment subscale of the Sport Commitment Questionnaire-2 measured PE enjoyment. The random intercept cross-lagged panel model, including repeated measures (within-level) and latent levels (between-level) of PE enjoyment, CRF and MF, was tested. Sex, body mass index, moderate to vigorous PA, and peak height velocity were included as covariates in the analysis.

RESULTS

Over 5 years, PE enjoyment decreased, CRF increased until Timepoint 3, and MF remained stable. Positive associations between PE enjoyment and fitness were observed, indicating the greater the PE enjoyment, the higher the fitness. For PE enjoyment, CRF and MF repeated measures were positively associated with measurement of the next year. PE enjoyment was positively related to CRF and MF the years thereafter.

CONCLUSION

Our findings highlight the importance of quality PE experiences for enjoyment and fitness gains during the transition from primary to secondary school. These findings are important given youth fitness levels are associated with future health status.

Association between time of assessment within a school year and physical fitness of primary school children

The dissociation of effects of age, time of assessment and cohort is a well-known challenge in developmental science. We examined effects of time of assessment in the school year on children's physical fitness using data from 75,362 German third-graders from seven cohorts. Children were tested once either in the first or second school term of third grade. Tests examined cardiorespiratory endurance (6-min run), coordination (star-run), speed (20-m sprint), lower (standing long jump) and upper (ball-push test) limbs muscle power, and flexibility (stand-and-reach test). We estimated the effect of time of assessment using a regression discontinuity design specified in a linear mixed model with random factors child and school and adjusted for age, sex, and cohort effects. Coordination, speed, and upper limbs muscle power were better in second compared to first school term, with boys exhibiting a larger increase of upper limbs muscle power than girls. There was no evidence for changes in cardiorespiratory endurance, lower limbs muscle power, and flexibility between assessments. Previously reported age and sex effects as well as secular fitness trends were replicated. There is thus evidence for improvement of some physical fitness components beyond age and cohort effects that presumably reflects the benefit of physical activity in physical education and other settings. Effects of assessment time should be taken into consideration in performance-based grading or norm-based selection of children.

Cardiorespiratory fitness attenuates the association between fatness and cardiometabolic risk in Chinese children

Background

Childhood obesity tends to persist into adulthood, predisposing individuals to cardiometabolic risk (CMR). This study aims to investigate the mediating role of cardiorespiratory fitness (CRF) in the associations between multiple fatness indicators and individual CMR markers and clustered CMR-score, and explore sex differences.

Methods

We recruited 1,557 children (age: 8 to 10, male/female: 52.7%/47.3%) in September 2022 in Ningbo, China. Physical examinations, overnight fasting blood test, and CRF was evaluated. The CMR-score was calculated by summing age- and sex-specific z scores of four CMR markers, including mean arterial blood pressure, triglycerides, the total cholesterol to high-density lipoprotein cholesterol ratio, and homeostatic model assessment for insulin resistance. Generalized linear mixed models were used to identify the associations, mediation analyses were performed to dissect the function of CRF.

Results

Partial correlation analyses revealed positive associations between high fatness indicators (including body mass index [BMI], BMI z score, body fat mass index [BFMI] and waist-to-height ratio [WHtR]) and increased CMR markers, whereas high CRF was associated with decreased CMR markers (all P < 0.05). In the mediation analyses, CRF emerged as a partial mediator, attenuating the relationship between four fatness indicators and CMR-score. Specifically, CRF mediated 6.5%, 7.7%, 5.3%, and 12.5% of the association between BMI, BMI z score, BFMI, WHtR and CMR-score (all P < 0.001). And the mediating effects of CRF between WHtR and four individual CMR markers was particularly robust, ranging from 10.4% to 21.1% (all P < 0.05). What's more, CRF mediates the associations between WHtR and CMR-score more pronounced in girls than boys with a mediation effect size of 17.3% (P < 0.001).

Conclusion

In Chinese children, CRF partially mitigates the adverse effects of fatness on CMR, underscoring the significance of enhancing CRF in children.

Integrated neuromuscular training intervention applied in schools induces a higher increase in salivary high molecular weight adiponectin and a more favorable body mass index, cardiorespiratory fitness and muscle strength in children as compared to the traditional physical education classes

Background

High-molecular-weight adiponectin (HMW-adiponectin) is a cardio-metabolic health protector. Objectives: (1) to compare body mass index (BMI), cardiorespiratory fitness (CRF) and muscle strength (MS) in healthy school-children depending on their baseline salivary-HMW-adiponectin concentration; and (2) to apply a 3-month integrated neuromuscular training (INT) and evaluate its effects on salivary-HMW-adiponectin concentration, BMI, CRF and MS in the same children. Additional goal: to identify if any potential changes during the 3-month period may be related to a potential change in salivary-HMW-adiponectin concentration.

Methods

Ninety children (7.4 ± 0.3 years) were recruited in primary schools and randomly allocated into control or intervention group. The intervention consisted of a 3-month INT applied during physical education (PE) classes, twice-weekly, while the control group had traditional PE classes. Body mass and height were measured, BMI was calculated and HMW-adiponectin was quantified in saliva. To assess CRF and MS, 800 m-run and hand-dynamometry were applied, respectively. All measurements were performed twice, at baseline and after 3 months.

Results

Children with higher baseline salivary-HMW-adiponectin have more favorable BMI (p = 0.006) and slightly higher CRF (p = 0.017) in comparison to the children with lower baseline salivary-HMW-adiponectin. There were no big changes after the 3-month-period neither in the control, nor the INT group. However, it is worthy to note that the INT induced slightly higher increase in salivary-HMW-adiponectin (p = 0.007), and a slightly higher improvement in BMI (p = 0.028), CRF (p = 0.043) and MS (p = 0.003), as compared to the traditional PE classes. Finally, the INT-induced improvement in CRF was associated with the increased post-salivary-HMW-adiponectin concentration (p = 0.022).

Conclusion

Main findings may suggest the potential utility of an INT as a cost-effective strategy that can be applied in schools to induce cardio-protective effects in school-children.

Reduced exercise capacity for muscle mass in adolescents living with obesity

BACKGROUND

Adolescents living with obesity (AlwO) can have limited exercise capacity. Exercise capacity can be predicted by a 2-factor model comprising lung function and leg muscle function, but no study has looked at cycling leg muscle function and its contribution to cycling exercise capacity in AlwO.

METHODS

Twenty-two nonobese adolescents and 22 AlwO (BMI > 95 percentile) were studied. Anthropometry, body composition (dual-energy X-ray absorptiometry), spirometry, 30-s isokinetic work capacity, and maximal exercise (cycle ergometry) were measured.

RESULTS

AlwO had greater total body mass, lean body mass, and lean leg mass (LLM). Lung function trended higher in AlwO. Leg 30-s work did not differ in absolute terms or per allometrically scaled LLM. Peak oxygen consumption did not differ between the groups in absolute terms or as percent predicted values (79.59 ± 14.6 vs. 82.3 ± 11.2% predicted control versus ALwO) but was lower in AlwO when expressed per kg body mass, kg lean body mass, scaled lean body mass, and LLM. Peak oxygen consumption related to both lung function and 30-s work, with no observed group effect. 30-s leg work related to the scaled LLM, with a small group effect. There was some correlation between leg work and time spent in moderate to vigorous physical activity in AlwO (rs = 0.39, p = .07).

CONCLUSION

AlwO have larger LLM and preserved exercise capacity, when expressed as percentage of predicted, but not per allometrically scaled LLM. Increasing time spent in moderate to vigorous activity may benefit AlwO.

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity

PURPOSE OF REVIEW

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk.

RECENT FINDINGS

Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

The Child Opportunity Index 2.0 and Disparities in Pediatric Cardiorespiratory Fitness

OBJECTIVE

To evaluate the effect of neighborhood-level characteristics on cardiorespiratory fitness (CRF) via peak oxygen consumption (VO2peak) for healthy pediatric patients.

STUDY DESIGN

The institutional cardiopulmonary exercise testing (CPET) database was analyzed retrospectively. All patients aged ≤ 18 years without a diagnosis of cardiac disease and with a maximal effort CPET were included. Patients were divided into three self-identified racial categories: White, Black, and Latinx. The Child Opportunity Index (COI) 2.0 was used to analyze social determinants of health. CRF was evaluated based on COI quintiles and race. Assessment of the effect of COI on racial disparities in CRF was performed using ANCOVA.

RESULTS

A total of 1753 CPETs met inclusion criteria. The mean VO2peak was 42.1 ± 9.8 mL/kg/min. The VO2peak increased from 39.1 ± 9.6 mL/kg/min for patients in the very low opportunity cohort to 43.9 ± 9.4 mL/kg/min for patients in the very high opportunity cohort. White patients had higher percent predicted VO2peak compared with both Black and Latinx patients (P < .01 for both comparisons). The racial differences in CRF were no longer significant when adjusting for COI.

CONCLUSION

In a large pediatric cohort, COI was associated with CRF. Racial disparities in CRF are reduced when accounting for modifiable risk factors.

High-intensity interval training and cardiorespiratory fitness in adults: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

High-intensity interval training (HIIT) is characterized by repeated bouts of relatively intense exercise interspersed with recovery periods. Previous studies have evaluated this exercise strategy with various population subgroups, regimens, and comparator groups, limiting the generalizability of findings. We performed a novel umbrella review to generate an up-to-date synthesis of the available evidence regarding the effect of HIIT on cardiorespiratory fitness (CRF) in adults as compared to non-exercise control and traditional continuous forms of exercise such as moderate-intensity continuous training (MICT).

METHODS

An umbrella review was conducted in accordance with the Preferred Reporting Items for Overviews of Reviews guideline. Seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) were searched until February 2024. Systematic reviews with meta-analyses comparing HIIT and active/non-active control conditions were included. Literature search, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers.

RESULTS

Twenty-four systematic reviews with meta-analyses, representing 429 primary studies and 12 967 unique participants, met the inclusion criteria. Most of the systematic reviews received moderate-to-critically low AMSTAR-2 scores. The data showed that HIIT, including the particularly intense variant "sprint interval training" (SIT), significantly increases CRF in adults compared to non-exercise control (standardized mean difference [SMD]: 0.28 to 4.31; weighted mean difference [WMD]: 3.25 to 5.5 mL/kg/min) and MICT (SMD: 0.18 to 0.99; WMD: 0.52 to 3.76 mL/kg/min). This effect was consistently observed across specific groups of individuals (e.g., apparently healthy adults, individuals with overweight/obesity, older adults, and high-level athletes) and HIIT modalities (e.g., low-volume HIIT, whole-body HIIT, home-based HIIT, aquatic HIIT, and short SIT).

CONCLUSION

Existing evidence from systematic reviews consistently supports the effect of HIIT on enhancing CRF in adults when compared to non-exercise control and MICT. Our findings offer a comprehensive basis that may potentially contribute to informing physical activity guidelines aimed at improving CRF in the general population.

Physical fitness in adolescent patients with familial Mediterranean fever

INTRODUCTION

Familial Mediterranean fever (FMF) is the most frequent monogenic auto-inflammatory disease worldwide responsible for episodes of fever, serositis and musculoskeletal symptoms. Inflammatory attacks are responsible for sedentary behavior and FMF patients may be at increased cardiovascular risk. Cardiorespiratory Fitness (CRF) and physical capacities during adolescence are associated with cardiovascular mortality in adulthood. In this study, we aimed to describe the physical fitness of FMF adolescents.

METHODS

A monocentric retrospective study at the Versailles Hospital between January 2020 and June 2023. All FMF patients over 14-year-old who had completed a routine physical test were included. Clinical and physical data including results of the 6-minute walking test, timed unipedal stance test, Ruffier-Dickson index, 30-seconds chair-stand test and sit-and-reach test were extracted from medical records. Results were compared with previously published normative reference values and criterion-referenced standards for healthy subjects.

RESULTS

Eighteen FMF patients (12 girls, 6 boys) were included. The median age was 16 years old [14-18]. Clinical history included joint symptoms (n = 11), chest pleuritis (n = 8), and leg pain (n = 11). Estimated VO2max was below the recommended thresholds in 13 patients, which predicts cardiovascular risk. Cardiovascular adaptation was poor in 11 patients. Low VO2max was associated with CRP > 5 mg/l on test day and history of joint symptoms.

CONCLUSION

FMF patients displayed altered physical capacities compared to normative values of healthy subjects. History of musculoskeletal pain, systemic inflammation and sedentary behavior may participate in impaired physical abilities and promote cardiovascular diseases in adulthood. Specific exercise programs could benefit patients for disease control and cardiovascular risk reduction.

The concurrent validity and test-retest reliability of a submaximal exercise test in adolescents with autism

PURPOSE

There is a need for valid and reliable clinical assessment tools to assess cardiorespiratory fitness (CRF) levels in adolescents with autism. Therefore, this study aimed to examine the concurrent validity and test-retest reliability of the Astrand-Rhyming Test (ART) in this population.

MATERIALS AND METHODS

45 adolescents with autism aged 12-18 years (n = 32 males, 14.47 ± 1.79 years) performed the ART twice (test-retest reliability) and completed a maximal cardiopulmonary exercise test (CPET) (concurrent validity). Reliability parameters included Pearson correlations, intraclass correlation coefficients (ICCs), standard error of measurements (SEM), minimal detectable changes (MDC), coefficients of variation, paired sample t-tests, linear regressions and Bland-Altman plots. The concurrent validity was evaluated with Pearson correlations, ICCs, paired sample t-tests, linear regressions and Bland-Altman plots.

RESULTS

Strong test-retest reliability (r = 0.84-0.85, ICC = 0.84-0.85) was found for the ART, but the wide limits of agreement intervals suggest the presence of substantial variability. The large SEM (4.73-5.08 mL/kg/min) and MDC (13.20-14.07 mL/kg/min) values suggest lower absolute reliability. Moderate to strong levels of association (r = 0.74-0.75) and agreement (ICC = 0.59-0.66) were found between estimated (ART1) and measured (CPET) VO2 max levels, but significant systematic differences (5.71-8.82 mL/kg/min) were observed.

CONCLUSION

The ART is an accessible and promising method to monitor submaximal CRF levels over time but is less appropriate to estimate maximal CRF levels in this population.

Better Cardiorespiratory Fitness Defined as VO2max Increases the Chance of Partial Clinical Remission and Prolongs Remission Duration in People with Newly Diagnosed Type 1 Diabetes

Introduction

An essential process affecting the course of type 1 diabetes (DM1) is the appearance and duration of clinical remission. One of the most important factors promoting the occurrence of remission is physical activity, due to increased activity of antioxidants, reduces insulin resistance and improves glucose transport. Maximal oxygen capacity (VO2max) is an objective measure of the body's aerobic capacity. To assess VO2max, oxygen uptake should be measured directly during the exercise test. The aim of the study was to evaluate the physical capacity in adults with DM1 and its relationship with the occurrence of partial clinical remission (pCR) during 2 years follow-up.

Methods

The pCR was assessed by the following mathematical formula: A1c (%) + [4 × insulin dose (U/kg/d)]. The result ⩽9 indicates pCR. VO2max was assessed between 6th and 24th month of diabetes duration using an ergospirometer (COSMED K5 System), during an exercise test carried out on a cycloergometer (RAMP incremental exercise test).

Results

The study group consisted of 32 adults with DM1. People with pCR were proved to have higher VO2max level [36.0 (33.0-41.5) vs 30.9 (26.5-34.4) ml/min/kg, P = .009. Univariate and multivariate regression confirmed a significant association between VO2max and presence of pCR [AOR 1.26 (1.05-1.52), P = .015]. Duration of remission was longer among group with higher VO2max results [15 (9-24) vs 9 (0-12) months, P = .043]. The positive relationship was observed between diabetes duration and VO2max (rs = 0.484, P = .005). Multivariate linear regression confirms a significant association between remission duration and VO2max (ml/min/kg) (β = 0.595, P = .002).

Conclusion

The higher VO2max, the better chance of partial clinical remission at 2 years of DM1 and longer duration of remission.

The International Fitness Scale (IFIS): A valid tool to assess physical fitness in French children

BACKGROUND

The need for monitoring regularly physical fitness in youth is well established for public health issues. The aim of this study was to assess the validity and reliability of the International Fitness Scale questionnaire (IFIS) to assess physical fitness in French children in the school context.

METHODS

A sample of 2 060 children (1054 boys), aged 10.6 ± 0.9 years, participated in the validation study while an independent sample of 366 children (175 boys), aged 9 to 11 years, participated in the assessment of reliability. Physical fitness was measured by a self-report of 5 questions with a 5-point Likert-scale (from very poor to very good) (IFIS), and also measured objectively by 4 field tests: cardiorespiratory fitness, muscular strength, speed/agility and flexibility. For the test-retest reliability assessment, children were instructed to complete the questionnaire twice, 1 week apart.

RESULTS

For all physical fitness components studied, children reporting a good or a very good physical fitness in the IFIS had better results in objective measurements of physical fitness tests compared to children reporting a very poor to an average physical fitness (p<0.001) without or with adjustments for sex, age and weight status. The reliability coefficients were acceptable for all components of physical fitness (0.59-0.72).

CONCLUSIONS

These results suggest that IFIS appears to be a useful instrument for teachers to estimate physical fitness levels of French children, possibly on a large scale.

A Coordinated School Health Program Effect on Cardiorespiratory Fitness of South Texas Preschool Children: A Cluster Randomized Trial

BACKGROUND

The purpose of this study was to assess the effects of the Bienestar/NEEMA Coordinated School Health Program (BN CSHP) on cardiorespiratory fitness (CRF) of preschool children.

METHODS

A cluster randomized trial was conducted of preschools in South Texas. Of 48 eligible schools, 28 were randomly assigned (14 intervention, 14 control). Family demographics and household health characteristics were collected from parents and CRF from children. Generalized linear mixed model (GLMM) was used to analyze the data.

RESULTS

Family demographics, household health characteristics, and children's weight, obesity prevalence, and sedentary activity of the control group were similar to the intervention group at baseline. After adjusting for covariates, the number of laps ran by children in the control group increased by 23% (CI: -5% to 60%) per each data collection period compared with 53% (CI: 7% to 119%) in the intervention group.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

State mandates, parent engagement, and funding are key for designing effective health and Physical Education (PE) programs.

CONCLUSION

Children in the BN CSHP, compared to those in the control group, had a significantly higher increase in their CRF. This finding is important because of the health benefits of CRF in children.

CLINICALTRIALS

gov Identifier: NCT05501392.

Investigation of Underlying Association between Anthropometric and Cardiorespiratory Fitness Markers among Overweight and Obese Adolescents in Canada

BACKGROUND

Adolescents who experience overweight or obesity commonly persist in these conditions into adulthood, thereby elevating their vulnerability to health issues. The focus of this study is on health risk markers such as body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), body surface area (BSA), and cardiorespiratory fitness (CRF). The objectives include updating normative values for BMI, WC, WHtR, and BSA in Canadian adolescents, establishing cardiometabolic risk zones, and developing a composite score considering both anthropometric and CRF markers.

METHODS

Involving 1864 adolescents, the study used the LMS method to generate percentile norms, stratified by age and sex. Cardiometabolic risk zones were established for each marker based on Z-scores, and a composite score was created.

RESULTS

An increase in WC of 5.8 and 7.4 cm for boys and girls, respectively, was observed since 1981. Forward multiple regression analyses were conducted to assess the robustness and validity of the proposed model. The results indicated that the model explained nearly 90% (R2 = 0.890) of the common variance between the composite score and the retained independent variables. Moreover, the model demonstrated a mean absolute error (MAE) of approximately 6 percentiles, confirming its high precision. Furthermore, these analyses yielded key thresholds for identifying adolescents at risk: the 70th percentile for high cardiometabolic risk and the 85th percentile for very-high risk.

CONCLUSIONS

Individually, WC or WHtR seem to be better markers for evaluating cardiometabolic risk than BMI during adolescence. However, CRF showed comparable importance to anthropometric markers in determining cardiometabolic risk. The simultaneous inclusion of anthropometric and CRF markers provides a better picture of the global cardiometabolic risk in adolescents.

Influence of vitamin D supplementation on muscle strength and exercise capacity in Mongolian schoolchildren: a randomised controlled trial

Objective

To determine whether weekly oral vitamin D supplementation influences grip strength, explosive leg power, cardiorespiratory fitness or spirometric lung volumes in Mongolian schoolchildren.

Methods

Multicentre, randomised, double-blind, placebo-controlled clinical trial conducted in children aged 6-13 years at baseline attending 18 schools in Ulaanbaatar. The intervention was weekly oral doses of 14,000 IU vitamin D3 (n=4418) or placebo (n=4433) for 3 years. Outcome measures were grip strength, standing long jump distance and serum 25-hydroxyvitamin D (25[OH]D) concentrations (determined in all participants), peak oxygen uptake (VO2peak, determined in a subset of 632 participants using 20-metre multi-stage shuttle run tests) and spirometric outcomes (determined in a subset of 1,343 participants).

Results

99.8% of participants had serum 25(OH)D concentrations <75 nmol/L at baseline, and mean end-study 25(OH)D concentrations in children randomised to vitamin D vs. placebo were 77.4 vs. 26.7 nmol/L (mean difference 50.7 nmol/L, 95% CI, 49.7 to 51.4). However, vitamin D supplementation did not influence mean grip strength, standing long jump distance, VO2peak, spirometric lung volumes or peak expiratory flow rate, either overall or within sub-groups defined by sex, baseline 25(OH)D concentration <25 vs. ≥25 nmol/L or calcium intake <500 vs. ≥500 mg/day.

Conclusion

A 3-year course of weekly oral supplementation with 14,000 IU vitamin D3 elevated serum 25(OH)D concentrations in Mongolian schoolchildren with a high baseline prevalence of vitamin D deficiency. However, this intervention did not influence grip strength, explosive leg power, peak oxygen uptake or spirometric lung volumes, either overall or in sub-group analyses.

A systematic review and cluster analysis approach of 103 studies of high-intensity interval training on cardiorespiratory fitness

AIMS

This study aims to systematically review the systematic reviews and meta-analyses examining the effect of high-intensity interval training (HIIT) protocols on improving cardiorespiratory fitness (CRF) and to characterize the main patterns of HIIT modalities using clustering statistical procedures to examine their potential differences on improving CRF. Finally, we aimed to develop a comprehensive guideline for reporting HIIT protocols.

METHODS AND RESULTS

A systematic review was conducted on PubMed and Web of Science from their inception to 31 October 2022 for systematic reviews and meta-analysis aimed at assessing the effect of HIIT on CRF in the entire study population. The Assessment of Multiple Systematic Reviews 2 tool was used to evaluate the risk of bias of each review. Additionally, a principal component analysis testing the data adequacy for the factor solution through the Kaiser-Meyer-Olkin procedure test was conducted. Once the number of factors was identified, in order to identify data patterns according to the main characteristics of the HIIT protocols, a two-step cluster analysis was conducted. Nineteen systematic reviews and/or meta-analyses comprising 103 studies were included. Clustering of systematic reviews and meta-analyses identified three HIIT modalities ('HIIT-normal mixed', 'HIIT-long running', and 'HIIT-short cycling') underlying the interventions across the included studies. Similar effectiveness in increasing CRF among the three HIIT modalities was observed. Subgroup analyses showed no significant differences in CRF by sex, weight status, study design, and baseline physical activity level (P > 0.05), but differences were observed by age group, and exercise intensity indicator was used in the HIIT programmes (P < 0.05).

CONCLUSION

All three HIIT modalities produced significant improvements of CRF, although some modalities showed greater changes for some specific age groups or intensity indicators.

Interval aerobic/resistance exercise training depresses adrenergic-induced apoptosis of lymphocytes in sedentary males

PURPOSE

Adrenergic stimulation affects lymphocyte autophagy and apoptosis by activating β1-adrenergic receptor (β1-AR) and G protein-coupled receptor kinase 2 (GRK-2) downstream signaling. This study investigated how combined aerobic and resistance exercise training on the interval or continuous pattern influences aerobic/muscular fitness and β1-AR/GRK-2 signaling, and corresponding apoptosis/autophagy of lymphocytes in sedentary males.

METHODS

Thirty-four sedentary males were randomized into interval training (IT, age = 22.5 ± 0.6 years, fitness level = 47.5 ± 0.9 mL/min/kg, body mass index (BMI) = 22.4 ± 0.4 kg/m2, n = 17) and continuous training (CT, age = 21.6 ± 0.4 years, fitness level = 45.2 ± 1.0 mL/min/kg, BMI = 22.2 ± 0.3 kg/m2, n = 17) groups. These subjects performed IT (bicycle exercise at alternating 40% and 80%VO2 reserve (VO2R) and isokinetic exercise at alternating 60°/s and 180°/s) or CT (bicycle exercise at continuously 60%VO2R and isokinetic exercise at continuously 120°/s) for 30 min/day, 5 days/week for 6 weeks. Aerobic capacity and muscular strength/endurance were determined by the graded exercise test (GXT) and isokinetic strength test, respectively. Blood lymphocyte autophagy/apoptosis and β1-AR/GRK-2 signaling were analyzed using flow cytometry.

RESULTS

Both IT and CT groups increased isokinetic strengths at various angular velocities, whereas only IT significantly enhanced muscle endurance, indicated by lowered fatigue index from 47.0 ± 1.3% to 41.8 ± 1.6% (P < 0.05). Moreover, the IT group (143 ± 7%) revealed a higher improvement in VO2peak than CT group (132 ± 6%) (P < 0.05). Acute GXT augmented (i) GRK-2 and protein kinase A expressions, (ii) LAMP-2 upregulation and acridine orange staining, (iii) mitochondrial transmembrane potential diminishing, caspase-3 activation, and phosphatidylserine (PS) exposure caused by epinephrine in blood lymphocytes. However, the degree of epinephrine-induced lymphocyte PS exposure potentiated by GXT was suppressed from 65.2 ± 5.2% to 47.4 ± 6.5% following 6 weeks of the IT (P < 0.05).

CONCLUSION

The IT may be considered more beneficial than CT in terms of improving aerobic/muscular fitness and simultaneously ameliorating apoptosis of blood lymphocyte evoked by intense exercise or adrenergic stimulation in sedentary males.

Global status of cardiorespiratory fitness and physical activity - Are we improving or getting worse?

Despite heightened recognition of the importance of cardiorespiratory fitness (CRF) to cardiovascular (CV) health, along with updated international consensus guidelines for physical activity (PA) and sedentary behavior (SB), significant proportions of the global adult population are physically inactive, and do not meet the threshold for CRF. Physical inactivity is considered a surrogate for low CRF given that the former is defined as not reaching the recommended minimum level of PA per week to derive a health benefit. Physical inactivity remains a major global public health problem despite decades of work by various United Nations agencies, and members of the international community to improve PA levels. Given the common coupling between physical inactivity and poor health status, it is reasonable to suggest that for a significant proportion of the global population, CRF is compromised by physical inactivity. This poses a longer-term risk to morbidity and mortality. Here we provide an indicative summary of the global status of CRF and PA and reference the implications for global health. We briefly reference opportunities moving forward, including reinforcement of the importance of engaging in movement from an early age, discouraging SB, and taking a life course approach to optimise healthy living for all.

Cross-sectional and longitudinal relationships between cardiorespiratory fitness and health-related quality of life in primary school children in England: the mediating role of psychological correlates of physical activity

AIMS

The aims were (1) to analyse the cross-sectional and longitudinal associations between children's cardiorespiratory fitness (CRF) and health-related quality of life (HRQoL) and (2) to examine whether these associations were mediated by physical activity self-efficacy and physical activity enjoyment.

METHODS

This study involved 383 children (10.0 ± 0.5 years) recruited from 20 primary schools in northwest England. Data were collected on two occasions 12 weeks apart. The number of laps completed in the 20-m Shuttle Run Test was used as the CRF indicator. HRQoL was assessed using the KIDSCREEN-10 questionnaire. Physical activity self-efficacy and enjoyment were assessed with the social-cognitive and Physical Activity Enjoyment Scale questionnaires, respectively. Linear mixed models with random intercepts (schools) assessed associations between CRF and HRQoL cross-sectionally, and longitudinally. Boot-strapped mediation procedures were performed, and indirect effects (IE) with 95% confidence intervals (CI) not including zero considered as statistically significant. Analyses were adjusted for sex, time of the year, socioeconomic status, waist-to-height ratio, maturation, and physical activity.

RESULTS

CRF was cross-sectionally associated with HRQoL (β = 0.09, 95% CI = 0.02, 0.16; p = .015). In the longitudinal analysis, CRF at baseline was associated with HRQoL at 12 weeks after additionally controlling for baseline HRQoL (β = 0.08, 95% CI = 0.002; p = .15, p = .045). Cross-sectionally, physical activity self-efficacy and enjoyment acted individually as mediators in the relationship between CRF and HRQoL (IE = 0.069, 95% CI = 0.038; p = .105 and IE = 0.045, 95% CI = 0.016; p = .080, respectively). In the longitudinal analysis, physical activity self-efficacy showed a significant mediating effect (IE = 0.025, 95% CI = 0.004; p = .054).

CONCLUSION

Our findings highlight the influence of CRF on children's psychological correlates of physical activity and their overall HRQoL.

Validity of the two-minute walk test to assess exercise capacity and estimate cardiorespiratory fitness in individuals after stroke: a cross-sectional study

OBJECTIVES

The purpose of this study was to investigate the construct validity of the 2-minute walk test (2MWT) to assess the exercise capacity and the criterion-concurrent validity of the 2MWT and the 6-minute walk test (6MWT) to estimate the cardiorespiratory fitness of ambulatory individuals with chronic stroke. In addition, to provide an equation to predict the distance covered in the 6MWT and another to predict the peak oxygen consumption (VO2peak) for these individuals.

METHODS

This is a cross-sectional and prospective study. A convenience sample with 57 individuals with chronic stroke was recruited. The 2MWT, the 6MWT and the cardiopulmonary exercise test (CPET) were performed in a laboratory. The Spearman's correlation coefficient was used to investigate the validity. To develop the equations, stepwise multiple linear regression analysis was used.

RESULTS

A significant correlation of very high magnitude between the distance covered in the 2MWT and the 6MWT was found (rs = 0.93; p < 0.001). A significant correlation of moderate magnitude between the distance covered in the 2MWT and the VO2peak (rs = 0.53; p < 0.001) similar to the correlation between the 6MWT and the VO2peak (rs = 0.55; p < 0,001) were found. Furthermore, an equation was developed to predict the VO2peak (R2 = 0.690; p < 0.001; VO2peak = 13.532 + 0.078*distance walked in the 2MWT +4.509*sex-0.172*age), and another to predict the distance covered in the 6MWT (R2 = 0.827; p < 0.001; MWT = -1.867 + 3.008*distance walked in the 2MWT).

CONCLUSION

2MWT showed adequate construct and concurrent validity. Furthermore, it is possible to use the prediction equations developed to estimate the VO2peak or the distance covered in the 6MWT.

Longitudinal Relationships Between Physical Fitness With Physical Self-Concept and Self-Esteem in Adolescents

Purpose: Physical fitness has shown to be positively related with young people's general mental health, mainly due to the changes in body composition derived from a regular sportive practice. Thus, the aim of this study was three-fold: 1) to analyze the relationship between physical fitness with the mental health status assessed as physical self-concept and self-esteem, 2) to study whether self-esteem offers longitudinal relationships with physical fitness three months after the first assessment, and 3) to know the most implicated variables of physical fitness in mental health variables. Method: A total of 1441 adolescents aged 12 to 19 years (mean=14.52; standard deviation=1.96 years), being the 49.5 % of them girls, from 4 high schools in Andalusia, Spain, participated in the study. The EUROFIT battery test was administered to the participants, as well as some questionaries to assess the physical self-concept and the self-steem. Physical tests and self-concept were assessed in an only temporal point, while self-esteem was analyzed longitudinally. Results: The results obtained indicated that physical self-concept was related to physical fitness, while self-esteem was especially related to the Course Navette test. Conclusions: These results suggest that having great levels of physical fitness, especially related to aerobic endurance, may help to have higher levels of physical self-concept and self-esteem as components of mental health in Spanish adolescents.

Cardiorespiratory fitness and physical activity in the lens of social justice - Reporting on the disparities that exist

Cardiorespiratory fitness (CRF), heavily influenced by physical activity (PA), represents a strong and independent risk factor for a wide range of health conditions, most notably, cardiovascular disease. Substantial disparities in CRF have been identified between white and non-white populations. These disparities may partly account for group differences in susceptibility to poor health outcomes, including non-communicable disease. Race and ethnic differences in CRF may partly be explained by social injustices rooted in persistent structural and systemic racism. These forces contribute to environments that are unsupportive for opportunities to achieve optimal CRF levels. This review aims to examine, through the lens of social justice, the inequities in key social ecological factors, including socioeconomic status, the built environment, and structural racism, that underly the systemic differences in CRF and PA in vulnerable communities. Further, this review highlights current public health initiatives, as well as opportunities in future research, to address inequities and enhance CRF through the promotion of regular PA.

2023 update: The importance of cardiorespiratory fitness in the United States

The American Heart Association issued a Policy Statement in 2013 that characterized the importance of cardiorespiratory fitness (CRF) as an essential marker of health outcomes and specifically the need for increased assessment of CRF. This statement summarized the evidence demonstrating that CRF is "one of the most important correlates of overall health status and a potent predictor of an individual's future risk of cardiovascular disease." Subsequently, this Policy Statement led to the development of a National Registry for CRF (Fitness Registry and the Importance of Exercise: A National Data Base [FRIEND]) which established normative reference values for CRF for adults in the United States (US). This review provides an overview of the progress made in the past decade to further our understanding of the importance of CRF, specifically related to prevention and for clinical populations. Additionally, this review overviews the evolvement and additional uses of FRIEND and summarizes a hierarchy of assessment methods for CRF. In summary, continued efforts are needed to expand the representation of data from across the US, and to include data from pediatric populations, to further develop the CRF Reference Standards for the US as well as further develop Global CRF Reference Standards.

Clinimetric Properties of the Steep Ramp Test to Assess Cardiorespiratory Fitness, Its Underlying Physiological Responses, and Its Current Applications: A Scoping Review

OBJECTIVE

Providing an overview of the clinimetric properties of the steep ramp test (SRT)-a short-term maximal exercise test-to assess cardiorespiratory fitness (CRF), describing its underlying physiological responses, and summarizing its applications in current clinical and research practice.

DATA SOURCES

MEDLINE (through PubMed), CINAHL Complete, Cochrane Library, EMBASE, and PsycINFO were searched for studies published up to July 2023, using keywords for SRT and CRF.

STUDY SELECTION

Eligible studies involved the SRT as research subject or measurement instrument and were available as full text articles in English or Dutch.

DATA EXTRACTION

Two independent assessors performed data extraction. Data addressing clinimetric properties, physiological responses, and applications of the SRT were tabulated.

DATA SYNTHESIS

In total, 370 studies were found, of which 39 were included in this study. In several healthy and patient populations, correlation coefficients between the work rate at peak exercise (WRpeak) attained at the SRT and oxygen uptake at peak exercise during cardiopulmonary exercise testing (CPET) ranged from .771-.958 (criterion validity). Repeated measurements showed intraclass correlation coefficients ranging from .908-.996 for WRpeak attained with the first and second SRT (test-retest reliability). Physiological parameters, like heart rate and minute ventilation at peak exercise, indicated that the SRT puts a lower burden on the cardiopulmonary system compared to CPET. The SRT is mostly used to assess CRF, among others as part of preoperative risk assessment, and to personalize interval training intensity.

CONCLUSIONS

The SRT is a practical short-term maximal exercise test that is valid for CRF assessment and to monitor changes in CRF over time in various healthy and patient populations. Its clinimetric properties and potential applications make the SRT of interest for a widespread implementation of CRF assessment in clinical and research practice and for personalizing training intensity and monitoring longitudinal changes in CRF.