Is peak VO2 a maximal index of children's aerobic fitness?

Cardiorespiratory Fitness Is an Indicator of Arterial Stiffness and Aortic Blood Pressure in Healthy Adolescents

Background/Objectives: We aimed to investigate the influence of cardiorespiratory fitness (CRF) and body composition on arterial stiffness. Methods: Carotid-to-femoral pulse wave velocity (cfPWV) and aortic systolic (ASBP) and diastolic (ADBP) blood pressure were compared between upper and lower tertiles of oxygen consumption at the aerobic threshold (VO2AerT), peak oxygen consumption (VO2peak), percentage of fat mass (FM%), and body mass index (BMI) in sixty adolescents (30 males and 30 females, 14.9 ± 2.1 years old). A stepwise multivariable linear regression analysis was performed to investigate the independent associations between VO2AerT and VO2peak and cfPWV, and between BMI and FM% and cfPWV with adjustments for age, sex, ASBP, and ADBP. Results: cfPWV and ADBP were lower in the second and third VO2AerT tertiles compared to the first tertile (cfPWV, 4.7 ± 0.5 and 4.7 ± 0.5 vs. 5.3 ± 0.8 m/s, p < 0.01; ADBP, 62 ± 7 and 62 ± 7 vs. 70 ± 8 mmHg, p < 0.01). ASBP was lower in the third VO2AerT tertile compared to the first tertile (94 ± 7 vs. 101 ± 12 mmHg, p = 0.05). ADBP was lower in the second VO2peak tertile compared to the first tertile (62 ± 7 vs. 68 ± 9 mmHg, p = 0.03). ASBP was lower in the first and second BMI tertiles compared to the third tertile (95 ± 8 and 95 ± 7 vs. 102 ± 11 mmHg, p = 0.02). The eight-variable model significantly contributed to the variance of cfPWV (F(8, 51) = 7.450, p < 0.01), accounting for 47% of the variance. Individually, age (p < 0.05) and ADBP (p < 0.01) significantly predicted cfPWV. Conclusions: Submaximal indicators of CRF such as VO2AerT should be considered as a part of the risk stratification of cardiovascular disease in healthy adolescents.

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.

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.

Confirming the attainment of maximal oxygen uptake within special and clinical groups: A systematic review and meta-analysis of cardiopulmonary exercise test and verification phase protocols

BACKGROUND AND AIM

A plateau in oxygen uptake ([Formula: see text]) during an incremental cardiopulmonary exercise test (CPET) to volitional exhaustion appears less likely to occur in special and clinical populations. Secondary maximal oxygen uptake ([Formula: see text]) criteria have been shown to commonly underestimate the actual [Formula: see text]. The verification phase protocol might determine the occurrence of 'true' [Formula: see text] in these populations. The primary aim of the current study was to systematically review and provide a meta-analysis on the suitability of the verification phase for confirming 'true' [Formula: see text] in special and clinical groups. Secondary aims were to explore the applicability of the verification phase according to specific participant characteristics and investigate which test protocols and procedures minimise the differences between the highest [Formula: see text] values attained in the CPET and verification phase.

METHODS

Electronic databases (PubMed, Web of Science, SPORTDiscus, Scopus, and EMBASE) were searched using specific search strategies and relevant data were extracted from primary studies. Studies meeting inclusion criteria were systematically reviewed. Meta-analysis techniques were applied to quantify weighted mean differences (standard deviations) in peak [Formula: see text] from a CPET and a verification phase within study groups using random-effects models. Subgroup analyses investigated the differences in [Formula: see text] according to individual characteristics and test protocols. The methodological quality of the included primary studies was assessed using a modified Downs and Black checklist to obtain a level of evidence. Participant-level [Formula: see text] data were analysed according to the threshold criteria reported by the studies or the inherent measurement error of the metabolic analysers and displayed as Bland-Altman plots.

RESULTS

Forty-three studies were included in the systematic review, whilst 30 presented quantitative information for meta-analysis. Within the 30 studies, the highest mean [Formula: see text] values attained in the CPET and verification phase protocols were similar (mean difference = -0.00 [95% confidence intervals, CI = -0.03 to 0.03] L·min-1, p = 0.87; level of evidence, LoE: strong). The specific clinical groups with sufficient primary studies to be meta-analysed showed a similar [Formula: see text] between the CPET and verification phase (p > 0.05, LoE: limited to strong). Across all 30 studies, [Formula: see text] was not affected by differences in test protocols (p > 0.05; LoE: moderate to strong). Only 23 (53.5%) of the 43 reviewed studies reported how many participants achieved a lower, equal, or higher [Formula: see text] value in the verification phase versus the CPET or reported or supplied participant-level [Formula: see text] data for this information to be obtained. The percentage of participants that achieved a lower, equal, or higher [Formula: see text] value in the verification phase was highly variable across studies (e.g. the percentage that achieved a higher [Formula: see text] in the verification phase ranged from 0% to 88.9%).

CONCLUSION

Group-level verification phase data appear useful for confirming a specific CPET protocol likely elicited [Formula: see text], or a reproducible [Formula: see text], for a given special or clinical group. Participant-level data might be useful for confirming whether specific participants have likely elicited [Formula: see text], or a reproducible [Formula: see text], however, more research reporting participant-level data is required before evidence-based guidelines can be given.

TRIAL REGISTRATION

PROSPERO (CRD42021247658) https://www.crd.york.ac.uk/prospero.

Assessment of Cardiorespiratory Fitness in 8-to-15-Year-Old Children with Overweight/Obesity by Three-Minute Step Test: Association with Degree of Obesity, Blood Pressure, and Insulin Resistance

OBJECTIVE

To assess cardiorespiratory fitness in children and adolescents with overweight/obesity using the Kasch pulse recovery (KPR) test, and its correlation with severity of obesity, insulin resistance, and blood pressure (BP).

METHODS

This is a retrospective analysis of baseline data from a study evaluating the efficacy of yoga for reduction of body mass index (BMI) in children aged 8-15 y with overweight/obesity. KPR three-minute step test was done. Children were classified into cardiorespiratory fitness categories based on the post-KPR heart rate (HR); the maximal oxygen consumption (VO2 max) was calculated, and the correlation analysis was done.

RESULTS

One hundred fifty-five children with mean age of 11.6 ± 1.8 y and mean BMI of 26.2 ± 4.1 kg/m2 were included. Mean post-KPR-HR and calculated VO2 max were 119 ± 14 per minute and 48.7 ± 5.6 mL/kg/min, respectively. In children < 13 y, cardiorespiratory fitness was excellent or very good in 28%, good or sufficient in 58%, and poor or very poor in 14%. BMI, waist circumference (WC), resting HR, systolic BP, and homeostatic model of insulin resistance (HOMA-IR) were higher among those with poor/very poor fitness, with WC z score being statistically significant (p = 0.015). Post-KPR-HR showed positive correlation with BMI z score (r = 0.16, p = 0.044), WC z score (r = 0.21, p = 0.011), and HOMA-IR (r = 0.22, p = 0.012).

CONCLUSION

In children with overweight/obesity, 14% had poor cardiorespiratory fitness. Post-KPR-HR and calculated VO2 max had good correlation with measures of obesity and HOMA-IR. Further studies evaluating cardiorespiratory fitness and normative data of VO2 max for Indian children are warranted.

What Tests are Used to Assess the Physical Qualities of Male, Adolescent Rugby League Players? A Systematic Review of Testing Protocols and Reported Data Across Adolescent Age Groups

BACKGROUND

Understanding the physical qualities of male, adolescent rugby league players across age groups is essential for practitioners to manage long-term player development. However, there are many testing options available to assess these qualities, and differences in tests and testing protocols can profoundly influence the data obtained.

OBJECTIVES

The aims of this systematic review were to: (1) identify the most frequently used tests to assess key physical qualities in male, adolescent rugby league players (12-19 years of age); (2) examine the testing protocols adopted in studies using these tests; and (3) synthesise the available data from studies using the most frequently used tests according to age group.

METHODS

A systematic search of five databases was conducted. For inclusion, studies were required to: (1) be original research that contained original data published in a peer-reviewed journal; (2) report data specifically for male, adolescent rugby league players; (3) report the age for the recruited participants to be between 12 and 19 years; (4) report data for any anthropometric quality and one other physical quality and identify the test(s) used to assess these qualities; and (5) be published in English with full-text availability. Weighted means and standard deviations were calculated for each physical quality for each age group arranged in 1-year intervals (i.e., 12, 13, 14, 15, 16, 17 and 18 years) across studies.

RESULTS

37 studies were included in this systematic review. The most frequently used tests to assess anthropometric qualities were body mass, standing height, and sum of four skinfold sites. The most frequently used tests to assess other physical qualities were the 10-m sprint (linear speed), 505 Agility Test (change-of-direction speed), Multistage Fitness Test (aerobic capacity), bench press and back squat one-repetition maximum tests (muscular strength), and medicine ball throw (muscular power). Weighted means calculated across studies generally demonstrated improvements in player qualities across subsequent age groups, except for skinfold thickness and aerobic capacity. However, weighted means could not be calculated for the countermovement jump.

CONCLUSION

Our review identifies the most frequently used tests, but highlights variability in the testing protocols adopted. If these tests are used in future practice, we provide recommended protocols in accordance with industry standards for most tests. Finally, we provide age-specific references for frequently used tests that were implemented with consistent protocols. Clinical Trial Registration This study was conducted in accordance with the Preferred Reporting Items of Systematic Review and Meta-analysis guidelines and was registered with PROSPERO (ID: CRD42021267795).

Reference Values of Cardiopulmonary Exercise Test Parameters in the Contemporary Paediatric Population

BACKGROUND

The evaluation of health status by cardiopulmonary exercise test (CPET) has shown increasing interest in the paediatric population. Our group recently established reference Z-score values for paediatric cycle ergometer VO_2max, applicable to normal and extreme weights, from a cohort of 1141 healthy children. There are currently no validated reference values for the other CPET parameters in the paediatric population. This study aimed to establish, from the same cohort, reference Z-score values for the main paediatric cycle ergometer CPET parameters, apart from VO_2max.

RESULTS

In this cross-sectional study, 909 healthy children aged 5-18 years old underwent a CPET. Linear, quadratic, and polynomial mathematical regression equations were applied to identify the best CPET parameters Z-scores, according to anthropometric parameters (sex, age, height, weight, and BMI). This study provided Z-scores for maximal CPET parameters (heart rate, respiratory exchange ratio, workload, and oxygen pulse), submaximal CPET parameters (ventilatory anaerobic threshold, VE/VCO₂ slope, and oxygen uptake efficiency slope), and maximum ventilatory CPET parameters (tidal volume, respiratory rate, breathing reserve, and ventilatory equivalent for CO₂ and O₂).

CONCLUSIONS

This study defined paediatric reference Z-score values for the main cycle ergometer CPET parameters, in addition to the existing reference values for VO_2max, applicable to children of normal and extreme weights. Providing Z-scores for CPET parameters in the paediatric population should be useful in the follow-up of children with various chronic diseases. Thus, new paediatric research fields are opening up, such as prognostic studies and clinical trials using cardiopulmonary fitness outcomes. Trial registration NCT04876209-Registered 6 May 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04876209 .

Effect of hypobaric hypoxia on hematological parameters related to oxygen transport, blood volume and oxygen consumption in adolescent endurance-training athletes

Objective

To analyze the effect of altitude on hematological and cardiorespiratory variables in adolescent athletes participating in aerobic disciplines.

Methods

21 females and 89 males participated in the study. All were adolescent elite athletes engaged in endurance sports (skating, running and cycling) belonging to two groups: permanent residents in either low altitude (LA, 966 m) or moderate altitude (MA, 2640 m). Hematocrit (Hct), hemoglobin concentration ([Hb]), total hemoglobin mass (Hbt), blood, plasma and erythrocyte volumes (BV, PV and EV), VO₂peak and other cardiorespiratory parameters were evaluated.

Results

Sex differences were evident both in LA and HA skating practitioners, the males having higher significant values than the females in oxygen transport-related hematological parameters and VO₂peak. The effect of altitude residence was also observed in Hct, [Hb], Hbt and EV with increased (14%–18%) values in the hematological parameters and higher EV (5%–24%). These results matched the significantly higher values of VO₂peak measured in MA residents. However, BV and PV did not show differences between LA and MA residents in any case. Sports discipline influenced neither the hematological variables nor most of the cardiorespiratory parameters.

Conclusions

LA and MA adolescent skaters showed sex differences in hematological variables. Endurance-trained male adolescent residents at MA had an increased erythropoietic response and a higher VO₂peak compared to their counterparts residing and training at LA. These responses are similar in the three aerobic sports studied, indicating that the variables described are highly sensitive to hypoxia irrespective of the sports discipline.

Associations between Second-Hand Tobacco Smoke Exposure and Cardiorespiratory Fitness, Physical Activity, and Respiratory Health in Children

BACKGROUND

Cardiorespiratory fitness (CRF) and physical activity (PA) are associated with a plethora of positive health effects. Many UK children fail to meet the recommended level of PA, with an observed decline in CRF levels over recent decades. Second-hand tobacco smoke (SHS) is responsible for a significant proportion of the worldwide burden of disease, but little is understood regarding the impact of SHS exposure on CRF and PA in children. The aim of this study was to test the associations between SHS exposure and CRF, PA, and respiratory health in children.

METHOD

Children (9-11 years) from UK primary schools in deprived areas participated (n = 104, 38 smoking households). Surveys determined household smoking, and exhaled carbon monoxide was used to indicate children's recent SHS exposure. CRF (VO_2peak) was assessed via maximal treadmill protocol using breath-by-breath analysis. Fractional exhaled nitric oxide and spirometry were utilised as indicators of respiratory health.

RESULTS

Linear regression models demonstrated that SHS exposure was negatively associated with allometrically scaled VO_2peak (B = -3.8, p = 0.030) but not PA or respiratory health.

CONCLUSION

The results indicate that SHS is detrimental to children's CRF; given that approximately one-third of children are regularly exposed to SHS, this important finding has implications for both public health and the sport and exercise sciences.

Effects of Active Video Games on Health-Related Physical Fitness and Motor Competence in Children and Adolescents With Overweight or Obesity: Systematic Review and Meta-Analysis

Background

Childhood obesity is one of the most important public health problems. Active video games (AVGs) have been proposed as an attractive alternative to increase energy expenditure and are being investigated to determine their effectiveness against childhood obesity.

Objective

The aim of this study is to summarize the existing research and draw conclusions about the effects of AVGs on health-related physical fitness and motor competence in children and adolescents with overweight and obesity.

Methods

The search strategy was applied to PubMed, MEDLINE, Web of Science, and SPORTDiscus, including randomized and nonrandomized controlled trials investigating the effects of AVG programs on health-related physical fitness and motor competence in children and adolescents with overweight and obesity. To measure the risk of bias in randomized and nonrandomized controlled trials, 2 different quality assessment tools were used. In total, 15 articles met the inclusion criteria, and the variables of interest were BMI, body fat percentage, cardiorespiratory fitness (CRF), waist circumference, fat-free mass, muscular fitness, and motor competence. A meta-analysis was performed.

Results

Positive effects were found for BMI and body fat percentage, favoring the AVG group compared with a control group with no intervention (mean difference −0.209; 95% CI −0.388 to −0.031 vs mean difference −0.879; 95% CI −1.138 to −0.602). Positive effects seem to be observed for CRF. The effects of AVG interventions on muscular fitness, fat-free mass, waist circumference, and motor competence are unclear.

Conclusions

AVG programs showed positive effects on BMI, body fat percentage, and CRF. AVG could be a good strategy to combat childhood obesity.

The Effect of an Intervention with Active Video Games Combined with Multicomponent Exercise on Cardiorespiratory fitness in Children with Overweight and Obesity: A Randomized Controlled Trial. (Preprint)

Background

Childhood overweight and obesity have become major global health problems and are negatively related with the cardiorespiratory fitness (CRF) level in school children and adolescents. Exercise, specifically multicomponent training, is effective for CRF improvement, but the main challenge is to ensure adherence to exercise in children with overweight and obesity. Therefore, new ways of exercising that are more attractive and motivational for this population are needed and playing or training with active video games (AVGs) has been proposed as an effective alternative because they require full-body movement and therefore increase energy expenditure.

Objective

The main aim of this study was to investigate the effects of an AVG intervention combined with multicomponent training on CRF at maximal and submaximal intensities in children with overweight or obesity.

Methods

We recruited 28 children (13 girls and 15 boys) aged 9 to 11 years with overweight or obesity from medical centers and divided them into 2 groups, an intervention group (n=20) that participated in a 5-month supervised AVG exercise program combined with multicomponent exercise, and a control group (n=8) that continued daily activities without modification. A maximal stress test to measure CRF using a walking-graded protocol with respiratory gas exchange was performed by the participants.

Results

The AVG group showed a significant decrease in heart rate and oxygen uptake for the same intensities in the submaximal stages of the maximal treadmill test, as well as a lower oxygen uptake percentage according to the individual maximal oxygen uptake, whereas the control group did not show overall changes. No change in the peak oxygen uptake (VO_2peak) was found.

Conclusions

A 5-month AVG intervention combined with multicomponent exercise had positive effects on CRF at submaximal intensity, showing a lower heart rate and oxygen uptake at the same intensities and displaying a lower oxygen uptake percentage according to the individual (VO_2peak). Greater benefits were found in children with the highest fat percentage.

Trial Registration

ClinicalTrials.gov NCT04418713; https://clinicaltrials.gov/show/NCT04418713

The Effects of Active Video Games on Health-Related Physical Fitness and Motor Competence in Children and Adolescents with Healthy Weight: A Systematic Review and Meta-Analysis

(1) Background: Poor levels of physical fitness and motor skills are problems for today's children. Active video games (AVG) could be an attractive strategy to help address them. The aim was to investigate the effects of AVG on health-related physical fitness and motor competence in children and adolescents with healthy weight. (2) Methods: Randomized and non-randomized controlled trials investigating the effects of AVG programs on health-related physical fitness and motor competence were included. Two different quality assessment tools were used to measure the risk of bias. Twenty articles met the inclusion criteria and the variables of interest were body mass index (BMI), body fat, cardiorespiratory fitness (CRF), muscular fitness and motor competence. (3) Results: AVG interventions seem to have benefits in BMI when lasting longer than 18 weeks (SMD, -0.590; 95% IC, -1.071, -0.108) and in CRF (SMD, 0.438; 95% IC, 0.022, 0.855). AVG seems to be a promising tool to improve muscular fitness and motor competence but the effects are still unclear due to the lack of evidence. (4) Conclusions: AVG seem to be an effective tool for improving some components of health-related physical fitness and motor competence in healthy-weight children and adolescents, but the effect on some fitness components needs further research. Therefore, AVG may be included as a strategy to improve health.

Understanding the role of aerobic fitness, spatial learning, and hippocampal subfields in adolescent males

Physical exercise during adolescence, a critical developmental window, can facilitate neurogenesis in the dentate gyrus and astrogliogenesis in Cornu Ammonis (CA) hippocampal subfields of rats, and which have been associated with improved hippocampal dependent memory performance. Recent translational studies in humans also suggest that aerobic fitness is associated with hippocampal volume and better spatial memory during adolescence. However, associations between fitness, hippocampal subfield morphology, and learning capabilities in human adolescents remain largely unknown. Employing a translational study design in 34 adolescent males, we explored the relationship between aerobic fitness, hippocampal subfield volumes, and both spatial and verbal memory. Aerobic fitness, assessed by peak oxygen utilization on a high-intensity exercise test (VO2 peak), was positively associated with the volumetric enlargement of the hippocampal head, and the CA1 head region specifically. Larger CA1 volumes were also associated with spatial learning on a Virtual Morris Water Maze task and verbal learning on the Rey Auditory Verbal Learning Test, but not recall memory. In line with previous animal work, the current findings lend support for the long-axis specialization of the hippocampus in the areas of exercise and learning during adolescence.

The Oxygen Uptake Plateau-A Critical Review of the Frequently Misunderstood Phenomenon

A flattening of the oxygen uptake–work rate relationship at severe exercise indicates the achievement of maximum oxygen uptake \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left({\text{VO}}_{2\max } \right)$$\end{document}VO2max. 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Peak Oxygen Uptake and Exercise Capacity of Children Undergoing Leukemia Treatment

The aim of the study was to assess the exercise capacity (VO_2peak) of children undergoing leukemia treatment and to compare the results with healthy children. Furthermore, we assessed the influence of treatment methods on the level of exercise capacity and the increase in sedentary behaviors. The study comprised 21 children (12 boys and 9 girls) undergoing treatment for acute lymphoblastic leukemia (ALL) (n = 13) and acute myeloid leukemia (AML) (n = 8). The subjects were aged 7-13 years (mean age 10.7, SD 2.0 years). Cardiorespiratory fitness was assessed by using the ergospirometry test. Progressive Godfrey protocol was performed. The level of physical activity was assessed by using the questions from the Health Behavior in School-Aged Children (HBSC 2018) questionnaire. The study results showed that children undergoing leukemia treatment were characterized by a reduced level of exercise capacity. The measured value of VO_2peak in the group of treated children was, on average, 22.16 mL·kg^-1·min^-1. The mean values of VO_2peak predicted for this age group were 45.48 mL·kg^-1·min^-1 (SD, 3.8). The measured value of VO_2peak in the study group with the division into age groups was, on average, 21.21 mL·kg^-1·min^-1 in the group of children aged 7-10 years. In the group of children aged 11-13 years, this parameter was 22.64 mL·kg^-1·min^-1. Lack of physical activity and failure to meet the standards for the minimum level of weekly physical activity (MVPA index-moderate-to-vigorous physical activity) probably contribute to the deterioration in exercise capacity level of cancer-treated children.

Simple tests of cardiorespiratory fitness in a pediatric population

A progressive, treadmill-based VO_2max is the gold standard of cardiorespiratory fitness determination but is rarely used in pediatric clinics due to time requirements and cost. Simpler and shorter fitness tests such as the Squat Test or Step Test may be feasible and clinically useful alternatives. However, performance comparisons of these tests to treadmill VO_2max tests are lacking. The primary aim of this cross-sectional study was to assess the correlation between Squat and Step Test scores and VO_2max in a pediatric population. As secondary outcomes, we calculated correlations between Rated Perceived Exertion Scale (RPE) scores, NIH PROMIS Physical Activity scores, and BMI z-score with VO_2max, and we also evaluated the ability of each fitness test to discriminate low and high-risk patients based on the FITNESSGram. Forty children aged 10–17 completed these simple cardiorespiratory fitness tests. Statistically significant correlations were observed between VO_2max and the Step Test (r = -0.549) and Squat Test (r = -0.429) scores, as well as participant BMI z-score (r = -0.458). RPE and PROMIS scores were not observed to be correlated with VO_2max. Area Under the Receiver Operator Curve was relatively high for BMI z-scores and the Step Test (AUC = 0.813, 0.713 respectively), and lower for the Squat Test (AUC = 0.610) in discriminating risk according to FITNESSGram Scores. In this sample, the Step Test performed best overall. These tests were safe, feasible, and may add great value in assessing cardiorespiratory fitness in a clinical setting.

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

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

Effects of a 12-Week Exercise Intervention on Subsequent Compensatory Behaviors in Adolescent Girls: An Exploratory Study

PURPOSE

Chronic exercise programs can induce adaptive compensatory behavioral responses through increased energy intake (EI) and/or decreased free-living physical activity in adults. These responses can negate the benefits of an exercise-induced energy deficit; however, it is unclear whether young people experience similar responses. This study examined whether exercise-induced compensation occurs in adolescent girls.

METHODS

Twenty-three adolescent girls, heterogeneous for weight status, completed the study. Eleven adolescent girls aged 13 years completed a 12-week supervised exercise intervention (EX). Twelve body size-matched girls comprised the nonexercise control group (CON). Body composition, EI, free-living energy expenditure (EE), and peak oxygen uptake (V˙O2) were measured repeatedly over the intervention.

RESULTS

Laboratory EI (EX: 9027, 9610, and 9243 kJ·d-1 and CON: 9953, 9770, and 10,052 kJ·d-1 at 0, 12, and 18 wk, respectively; effect size [ES] = 0.26, P = .46) and free-living EI (EX: 7288, 6412, and 5273, 4916 kJ·d-1 and CON: 7227, 7128, and 6470, 6337 kJ·d-1 at 0, 6, 12, and 18 wk, respectively; ES ≤ 0.26, P = .90) did not change significantly over time and were similar between groups across the duration of the study. Free-living EE was higher in EX than CON (13,295 vs 12,115 kJ·d-1, ES ≥ 0.88, P ≥ .16), but no significant condition by time interactions were observed (P ≥ .17).

CONCLUSION

The current findings indicate that compensatory changes in EI and EE behaviors did not occur at a group level within a small cohort of adolescent girls. However, analysis at the individual level highlights large interindividual variability in behaviors, which suggests a larger study may be prudent to extend this initial exploratory research.

Prediction of peak V˙ O2 in Children and Adolescents With HIV From an Incremental Cycle Ergometer Test

PURPOSE

To examine the capacity of physiological variables and performance to predict peak oxygen consumption (peak V˙ O₂) in children and adolescents living with HIV.

METHOD

Sixty-five children and adolescents living with HIV (30 boys) aged 8-15 years, participated in the study. Peak V˙ O₂ was measured by breath-by-breath respiratory exchange during an incremental cycle ergometer until volitional exhaustion. Information on the time to exhaustion, maximal power output (Pmax), and peak heart rate (peak HR) were also recorded.

RESULTS

Predictive models were developed and all equations showed the ability of performance variables to predict peak V˙ O₂. However, Model 1 was based only on Pmax by following equation: Y = 338.8302 + (Pmax [W] * 11.16435), R² = 0.90 and standard error of estimation (SEE) = 180 ml ⋅ min^-1.

CONCLUSION

The V˙ O₂ peak can be predicted simply by the Pmax obtained from the incremental cycle ergometer test. This protocol is a valid and useful tool for monitoring the aerobic fitness of children and adolescents living with HIV, especially in resource-limited settings.

Interpreting Aerobic Fitness in Youth: The Fallacy of Ratio Scaling

In this paper, we draw on cross-sectional, treadmill-determined, peak oxygen uptake data, collected in our laboratory over a 20-year period, to examine whether traditional per body mass (ratio) scaling appropriately controls for body size differences in youth. From an examination of the work of pioneering scientists and the earliest studies of peak oxygen uptake, we show how ratio scaling appears to have no sound scientific or statistical rationale. Using simple methods based on correlation and regression, we demonstrate that the statistical relationships, which are assumed in ratio scaling, are not met in groups of similar aged young people. We also demonstrate how sample size and composition can influence relationships between body mass and peak oxygen uptake and show that mass exponents derived from log-linear regression effectively remove the effect of body mass. Indiscriminate use of ratio scaling to interpret young people's fitness, to raise "Clinical Red Flags", and to assess clinical populations concerns us greatly, as recommendations and conclusions based upon this method are likely to be spurious. We urge those involved with investigating youth fitness to reconsider how data are routinely scaled for body size.

Validity of the Supramaximal Test to Verify Maximal Oxygen Uptake in Children and Adolescents

Purpose: This study had 2 objectives: (1) to examine whether the validity of the supramaximal verification test for maximal oxygen uptake ( V˙O2max ) differs in children and adolescents when stratified for sex, body mass, and cardiorespiratory fitness and (2) to assess sensitivity and specificity of primary and secondary objective criteria from the incremental test to verify V˙O2max . Methods: In total, 128 children and adolescents (76 male and 52 females; age: 9.3-17.4 y) performed a ramp-incremental test to exhaustion on a cycle ergometer followed by a supramaximal test to verify V˙O2max . Results: Supramaximal tests verified V˙O2max in 88% of participants. Group incremental test peak V˙O2 was greater than the supramaximal test (2.27 [0.65] L·min^-1 and 2.17 [0.63] L·min^-1; P < .001), although both were correlated (r = .94; P < .001). No differences were found in V˙O2 plateau attainment or supramaximal test verification between sex, body mass, or cardiorespiratory fitness groups (all Ps > .18). Supramaximal test time to exhaustion predicted supramaximal test V˙O2max verification (P = .04). Primary and secondary objective criteria had insufficient sensitivity (7.1%-24.1%) and specificity (50%-100%) to verify V˙O2max . Conclusion: The utility of supramaximal testing to verify V˙O2max is not affected by sex, body mass, or cardiorespiratory fitness status. Supramaximal testing should replace secondary objective criteria to verify V˙O2max .

A Systematic Approach to Interpreting the Cardiopulmonary Exercise Test in Pediatrics

The use of cardiopulmonary exercise testing 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. Clinical interpretation of the results of a cardiopulmonary exercise test in pediatrics requires specific knowledge with regard to pathophysiological responses and interpretative strategies that can be adapted to address concerns specific to the child's medical condition or disability. In this review, the authors outline the 7-step interpretative approach that they apply in their outpatient clinic for diagnostic, prognostic, and evaluative purposes. This approach allows the pediatric clinician to interpret cardiopulmonary exercise testing results in a systematic order to support their physiological reasoning and clinical decision making.

Ability of preschoolers to achieve maximal exercise and its correlation with oxygen uptake efficiency slope ∼ an observational study by direct cardiopulmonary exercise testing

The oxygen uptake efficiency slope (OUES) is a well-established substitute for maximum oxygen uptake ((Equation is included in full-text article.)O2 max) in submaximal exercise effort among adolescents and adults. Few studies have analyzed the exercise capacity (EC) and OUES of children aged 4 to 6 (preschoolers). Body fat has been proved to negatively affect EC among schoolchildren. The purposes of this study were to assess the capacity of preschoolers in achieving (Equation is included in full-text article.)O2 max and evaluate the correlation of peak metabolic equivalent (peak MET) and peak oxygen consumption (peak O2) with OUES. We also evaluated if body fat affected EC among preschoolers.Forty-three preschoolers under the ramped Bruce protocol of treadmill exercise testing had been retrospectively studied. The criteria for achieving (Equation is included in full-text article.)O2 max included respiratory exchange ratio (RER) >1.1, heart rate (HR) >85% of age-predicted maximum, and HR >200 bpm. OUES was calculated by the 75% (OUES-75) and the entire (OUES-100) duration of the testing and normalized by body surface area. Body fat was measured using vector bioelectrical impedance analysis. The fat mass (FM) index and fat-free mass index (FFMI) were defined as FM or FFM (kg) divided by height squared (m), respectively.The mean age of the participants was 5.70 ± 0.56. Seventy-nine percent of preschoolers met at least 1 criterion, 36.84% met 2 criteria, and none met all 3 criteria for (Equation is included in full-text article.)O2. OUES-75 was moderately positively correlated with peak MET (P = .034; Spearman's rho = 0.324) and peak O2 (P <.001; Spearman's rho = 0.667). OUES-100 was moderately to highly positively correlated with peak MET (P <.001; Spearman's rho = 0.592) and peak O2 (P <.001; Spearman's rho = 0.825). There were moderate to high positive correlations between FFMI and peak O2 (P <.001; Spearman's rho = 0.668), OUES-75 (P <.001; Spearman's rho = 0.642), and OUES-100 (P < .001; Spearman's rho = 0.670).None of the preschoolers reached all 3 criteria for (Equation is included in full-text article.)O2max. OUES-75 and OUES-100 might be indicators of peak O2 at submaximal effort. Preschoolers with higher FFMI had better EC during treadmill exercise testing.

Children with Burn Injury Have Impaired Cardiac Output during Submaximal Exercise

INTRODUCTION

Burn trauma damages resting cardiac function; however, it is currently unknown if the cardiovascular response to exercise is likewise impaired. We tested the hypothesis that, in children, burn injury lowers cardiac output (Q˙) and stroke volume (SV) during submaximal exercise.

METHODS

Five children with 49% ± 4% total body surface area (BSA) burned (two female, 11.7 ± 1 yr, 40.4 ± 18 kg, 141.1 ± 9 cm) and eight similar nonburned controls (five female, 12.5 ± 2 yr, 58.0 ± 17 kg, 147.3 ± 12 cm) with comparable exercise capacity (peak oxygen consumption [peak V˙O2]: 31.9 ± 11 vs 36.8 ± 8 mL O2·kg·min, P = 0.39) participated. The exercise protocol entailed a preexercise (pre-EX) rest period followed by 3-min exercise stages at 20 W and 50 W. V˙O2, HR, Q˙ (via nonrebreathing), SV (Q˙/HR), and arteriovenous O2 difference ([a-v]O2diff, Q˙/ V˙O2) were the primary outcome variables.

RESULTS

Using a 2-way factorial ANOVA (group [G] × exercise [EX]), we found that Q˙ was approximately 27% lower in the burned than the nonburned group at 20 W of exercise (burned 5.7 ± 1.0 vs nonburned: 7.9 ± 1.8 L·min) and 50 W of exercise (burned 6.9 ± 1.6 vs nonburned 9.2 ± 3.2 L·min) (G-EX interaction, P = 0.012). SV did not change from rest to exercise in burned children but increased by approximately 24% in the nonburned group (main effect for EX, P = 0.046). Neither [a-v] O2diff nor V˙O2 differed between groups at rest or exercise, but HR response to exercise was reduced in the burn group (G-EX interaction, P = 0.004). When normalized to BSA, SV (index) was similar between groups; however, Q˙ (index) remained attenuated in the burned group (G-EX interaction, P < 0.008).

CONCLUSIONS

Burned children have an attenuated cardiovascular response to submaximal exercise. Further investigation of hemodynamic function during exercise will provide insights important for cardiovascular rehabilitation in burned children.

Yoga versus physical exercise for cardio-respiratory fitness in adolescent school children: a randomized controlled trial

Background Yoga is very effective in improving health especially cardio-respiratory fitness and also overall performance in adolescents. There are no large numbers of randomized controlled studies conducted on comparing yoga with physical activity for cardio-respiratory fitness in adolescent school children with large sample size. Objective Aerobic training is known to improve physical and cardio-respiratory fitness in children. Cardio-respiratory fitness is an important indicator of health in children. In this study we evaluate the effects of yoga versus physical exercise training on cardio-respiratory fitness in adolescent school children. Subjects Eight hundred two school students from 10 schools across four districts were recruited for this study. Methods In this prospective two arm RCT around 802 students were randomized to receive daily one hour yoga training (n = 411) or physical exercise (n = 391) over a period of two months. VO2 max was estimated using 20 m shuttle run test. However, yoga (n = 377) and physical exercise (n = 371) students contributed data to the analyses. Data was analysed using students t test. Results There was a significant improvement in VO2 max using 20 m Shuttle run test in both yoga (p < 0.001) and exercise (p < 0.001) group following intervention. There was no significant change in VO2 max between yoga and physical exercise group following intervention. However, in the subgroup with an above median cut-off of VO2 max; there was a significant improvement in yoga group compared to control group following intervention (p = 0.03). Conclusion The results suggest yoga can improve cardio-respiratory fitness and aerobic capacity as physical exercise intervention in adolescent school children.

Verification of Maximal Oxygen Uptake in Obese and Nonobese Children

PURPOSE

The purpose of this study was to examine whether a supramaximal constant-load verification test at 105% of the highest work rate would yield a higher V˙O2max when compared with an incremental test in 10- to 12-yr-old nonobese and obese children.

METHODS

Nine nonobese (body mass index percentile = 57.5 ± 23.2) and nine obese (body mass index percentile = 97.9 ± 1.4) children completed a two-test protocol that included an incremental test followed 15 min later by a supramaximal constant-load verification test.

RESULTS

The V˙O2max achieved in verification testing (nonobese = 1.71 ± 0.31 L·min and obese = 1.94 ± 0.47 L·min) was significantly higher than that achieved during the incremental test (nonobese = 1.57 ± 0.27 L·min and obese = 1.84 ± 0.48 L·min; P < 0.001). There was no significant group (i.e., nonobese vs obese)-test (i.e., incremental vs verification) interaction, suggesting that there was no effect of obesity on the difference between verification and incremental V˙O2max (P = 0.747).

CONCLUSION

A verification test yielded significantly higher values of V˙O2max when compared with the incremental test in obese children. Similar results were observed in nonobese children. Supramaximal constant-load verification is a time-efficient and well-tolerated method for identifying the highest V˙O2 in nonobese and obese children.

Relation of oxygen uptake to work rate in prepubertal healthy children - reference for VO2 /W-slope and effect on cardiorespiratory fitness assessment

PURPOSE

Exercise testing by cycle ergometer allows to observe the interaction between oxygen uptake (VO₂ ) and workload (W), and VO₂ /W-slope can be used as a diagnostic tool. Respectively, peak oxygen uptake (VO_2PEAK ) can be estimated by maximal workload. We aim to determine reference for VO₂ /W-slope among prepubertal children and define agreement between estimated and measured VO_2PEAK .

METHODS

A total of 38 prepubertal children (20 girls) performed a maximal cycle ergometer test with respiratory gas analysis. VO₂ /W-slopes were computed using linear regression. Agreement analysis by Bland and Altman for estimated and measured VO_2PEAK was carried out including limits of agreement (LA). Determinants for VO₂ /W-slopes and estimation bias were defined.

RESULTS

VO2/W-slope was in both girls and boys ≥9·4 and did not change with exercise level, but the oxygen cost of exercise was higher among physically more active children. Estimated VO_2PEAK had 6·4% coefficient of variation, and LA varied from 13% underestimation to 13% overestimation. Bias had a trend towards underestimation along lean mass proportional VO_2PEAK . The primary determinant for estimation bias was VO2/W-slope (β = -0·65; P<0·001).

CONCLUSION

The reference values for VO₂ /W-slope among healthy prepubertal children were similar to those published for adults and among adolescents. Estimated and measured VO_2PEAK should not be considered to be interchangeable because of the variation in the relationship between VO₂ and W. On other hand, variation in the relationship between VO₂ and W enables that VO₂ /W-slope can be used as a diagnostic tool.

Top 10 Research Questions Related to Youth Aerobic Fitness

Peak oxygen uptake ([Formula: see text]₂) is internationally recognized as the criterion measure of youth aerobic fitness, but despite pediatric data being available for almost 80 years, its measurement and interpretation in relation to growth, maturation, and health remain controversial. The trainability of youth aerobic fitness continues to be hotly debated, and causal mechanisms of training-induced changes and their modulation by chronological age, biological maturation, and sex are still to be resolved. The daily physical activity of youth is characterized by intermittent bouts and rapid changes in intensity, but physical activity of the intensity and duration required to determine peak [Formula: see text]₂ is rarely (if ever) experienced by most youth. In this context, it may therefore be the transient kinetics of pulmonary [Formula: see text]₂ that best reflect youth aerobic fitness. There are remarkably few rigorous studies of youth pulmonary [Formula: see text]₂ kinetics at the onset of exercise in different intensity domains, and the influence of chronological age, biological maturation, and sex during step changes in exercise intensity are not confidently documented. Understanding the trainability of the parameters of youth pulmonary [Formula: see text]₂ kinetics is primarily based on a few comparative studies of athletes and nonathletes. The underlying mechanisms of changes due to training require further exploration. The aims of the present article are therefore to provide a brief overview of aerobic fitness during growth and maturation, increase awareness of current controversies in its assessment and interpretation, identify gaps in knowledge, raise 10 relevant research questions, and indicate potential areas for future research.

A novel treadmill protocol for exercise testing in children: the British Columbia Children's Hospital protocol

BACKGROUND

Exercise testing in children is widely recommended for a number of clinical and prescriptive reasons. Many institutions continue to use the Bruce protocol for treadmill testing; however, with its incremental changes in speed and grade, it has challenges for practical application in children. We have developed a novel institutional protocol (British Columbia Children's Hospital (BCCH)), which may have better utility in paediatric populations.

AIM

To determine if our institutional protocol yields similar peak responses in minute ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (RER), metabolic equivalents (METS) and heart rate (HR) when compared with the traditional Bruce protocol.

METHODS

On two different occasions, 70 children (boys=33; girls=37) aged 10-18 years completed an exercise test on a treadmill using each of the protocols. During each test, metabolic gas exchange parameters were measured. HR was monitored continuously during exercise using an HR monitor.

RESULTS

Physiological variables were similar between the two protocols (median (IQR); rs): VE (L/min) (BCCH=96.7 (72.0-110.2); Bruce=99.2 (75.6-120.0); rs=0.95), peak VO2 (mL/min) (BCCH=2897 (2342-3807); Bruce=2901 (2427-3654); rs=0.94) and METS (BCCH=16.2 (14.8-17.7); Bruce=16.4 (14.7-17.9); rs=0.89). RERs were similar (BCCH=1.00 (0.96-1.02); Bruce=1.03 (0.99-1.07); rs=0.48). Total exercise time (in seconds) was longer for the BCCH protocol: BCCH=915 (829-1005); Bruce=810 (750-919); rs=0.67.

CONCLUSION

The BCCH protocol produces similar peak exercise responses to the Bruce protocol and provides an alternative for clinical exercise testing in children.

Effects of Two-Week High-Intensity Interval Training on Cognition in Adolescents – A Randomized Controlled Pilot Study

We investigated the effects of a two-week high-intensity interval training (HIT) on cognition in adolescents.

The participants were recruited from local high schools with an electronic messaging system. The HIT group participated in 4 high-intensity interval running sessions and 2 circuit training sessions. The control group (CG) continued their usual habits. Reaction time, choose reaction time, working memory, visual memory, and learning were assessed by computerized CogState test battery. The intervention effect was investigated with repeated measures ANOVA and the effect size by Morris dppc2.

The total of 25 participants aged 17–20 years participated in the baseline measurements and were randomized into the intervention (

The study on HIT produced mixed effects on cognition in adolescents. Studies with a longer intervention period and larger sample sizes are warranted to further explore HIT effects on cognition.

Prediction of peak oxygen uptake in children using submaximal ratings of perceived exertion during treadmill exercise

Purpose

This study assessed the utility of the Children’s Effort Rating Table (CERT) and the Eston–Parfitt (EP) Scale in estimating peak oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak) in children, during cardiopulmonary exercise testing (CPET) on a treadmill.

Methods

Fifty healthy children (n = 21 boys; 9.4 ± 0.9 years) completed a continuous, incremental protocol until the attainment of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak. Oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2) was measured continuously, and ratings of perceived exertion (RPE) were estimated at the end of each exercise stage using the CERT and the EP Scale. Ratings up to- and including RPE 5 and 7, from both the CERT (CERT 5, CERT 7) and EP Scale (EP 5, EP 7), were linearly regressed against the corresponding \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2, to both maximal RPE (CERT 10, EP 10) and terminal RPE (CERT 9, EP 9).

Results

There were no differences between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from CERT 5, CERT 7, EP 5 and EP 7 when extrapolated to either CERT 9 or EP 9 (P > 0.05). Pearson’s correlations of r = 0.64–0.86 were observed between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak, for all perceptual ranges investigated. However, only EP 7 provided a small difference when considering the standard error of estimate, suggesting that the prediction of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from EP 7 would be within 10 % of measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak.

Conclusions

Although robust estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak may be elicited using both the CERT and EP Scale during a single CPET with children, the most accurate estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak occur when extrapolating from EP 7.

Comparison between parameters from maximal cycle ergometer test first without respiratory gas analysis and thereafter with respiratory gas analysis among healthy prepubertal children

It is important to distinguish true and clinically relevant changes and methodological noise from measure to measure. In the clinical practice, maximal cycle ergometer tests are typically performed first without respiratory gas analysis and thereafter, if needed, with respiratory gas analysis. Therefore, we report a comparison of parameters from maximal cycle ergometer exercise tests that were done first without respiratory gas analysis and thereafter with it in 38 prepubertal and healthy children (20 girls, 18 boys). The Bland-Altman method was used to assess agreement in maximal workload (WMAX), heart rate (HR), and systolic blood pressure (SBP) between rest and maximum. Girls achieved higher WMAX in the exercise tests with respiratory gas analysis compared with exercise tests without respiratory gas analysis (p = 0.016), whereas WMAX was similar in the tests among boys. Maximal HR (proportional offset, -1%; coefficients of variation, 3.3%) and highest SBP (proportional offset, 3%; coefficients of variation, 10.6%) were similar in the tests among children. Precision and agreement for HR improved and precision for SBP worsened with increasing exercise intensity. Heteroscedasticity was not observed for WMAX, HR, or SBP. We conclude that maximal cycle ergometer tests without and with respiratory gas analysis can be used consecutively because measurement of respiratory gases did not impair performance or have a significant effect on the maximality of the exercise tests. Our results suggest that similar references can be used for children who accept or refuse using a mask during a maximal exercise test.

The clinimetric properties of aerobic and anaerobic fitness measures in adults with cerebral palsy: A systematic review of the literature

OBJECTIVE

To analyze the clinimetric properties of maximal aerobic and anaerobic fitness measurement protocols in adults with cerebral palsy (CP).

DATA SOURCES

A systematic search through March 2015 of databases PubMed, Embase, SPORTDiscus and PsycINFO was performed with medical subject heading terms for 'cerebral palsy' combined with search terms adults or adolescents and multiple text words for fitness and exercise tests that yielded 864 articles.

STUDY SELECTION

Abstracts were screened by two reviewers to identify use of maximal fitness measurements in adolescents (14-18yrs) or adults (>18yrs) with CP of all abilities. Ninety-four articles were reviewed. No studies of adolescent (14-18yrs) qualified. Eight articles reported clinimetric properties for adults with CP who walk or propel a wheelchair independently. Five articles reported on aerobic capacity, one reported on anaerobic capacity and two reported on both.

DATA EXTRACTION

Methodological quality of the studies was rated using portions of the COSMIN (COnsensus-based Standards for the selection of health status Measurement INstruments) checklist. Quality of the measurement protocols was evaluated based on statistical strength of the clinimetrics. Synthesis of the overall evidence was based on the Cochrane review group guidelines which combine methodological quality and statistical strength.

DATA SYNTHESIS

Eight articles reported on 4 aerobic and 1 anaerobic protocols. Overall synthesis revealed that for ambulatory adults with CP there is (i) moderate evidence for good reliability and good construct validity of maximal aerobic and anaerobic cycle tests, (ii) moderate evidence for good criterion validity of sub-maximal aerobic cycle tests, and (iii) strong evidence for poor criterion validity of the six-minute walk test as a maximal aerobic test. And for adults who propel a wheelchair there is limited evidence of good reliability for maximal aerobic wheelchair ergometer tests.

CONCLUSIONS

Limited quality research exists on the clinimetric properties of aerobic and anaerobic capacity measures for adults with CP who have independent mobility. Quality aerobic and anaerobic measures for adults with more severe mobility impairments are absent.

The effects of a peer modeling intervention on cardiorespiratory fitness parameters and self-efficacy in obese adolescents

Inconsistencies exist in the assessment and interpretation of peak VO2 in the pediatric obese population, as cardiorespiratory fitness assessments are effort-dependent and psychological variables prevalent in this population must be addressed. This study examined the effect of a peer modeling intervention on cardiorespiratory fitness performance and task self-efficacy in obese youth completing a maximal treadmill test. Forty-nine obese (BMI ≥ 95th percentile for age and sex) youth were randomized to an experimental (received an intervention) or to a control group. The outcome variables were mean and variability cardiorespiratory fitness (peak VO2, heart rate, duration, respiratory exchange ratio), rating of perceived exertion, and task self-efficacy scores. Irrespective of whether a mean or variability score was used, receiving the intervention was associated with non-significant trends in fitness parameters and task self-efficacy over time, favoring the experimental group. Cardiorespiratory fitness and task self-efficacy were moderately correlated at both time points. To elucidate the aforementioned findings, psychosocial factors affecting obese youth and opportunities to modify the peer modeling intervention should be considered. Addressing these factors has the potential to improve standard of care in a clinical setting regarding pretest patient education.

Measures of cardiorespiratory fitness in relation to measures of body size and composition among children

BACKGROUND

In the exercise testing measures of cardiorespiratory fitness need to be scaled by body size or composition to enable comparison between individuals. Traditionally used weight-proportional measures are potentially confounded by body adiposity that hampers their interpretation and applicability in the clinical assessment of cardiorespiratory fitness.

OBJECTIVE

We aimed to find the most appropriate measure of body size or composition for scaling of measures of cardiorespiratory fitness among children.

METHODS

We assessed body weight and height, maximal workload (W MAX ) and maximal oxygen uptake (VO2 MAX ) using cycle ergometer exercise test with respiratory gas analysis and body lean mass (LM) and fat mass (FM) by dual-energy X-ray absorptiometry and by bioimpedance analysis among 38 children. The data were analysed using Pearson's coefficients for correlation and stepwise linear regression models.

RESULTS

Lean mass (r > 0.54) and height (r > 0.51) had stronger positive correlations with absolute W MAX and VO2 MAX than weight (r > 0.30) in girls and boys. None of the measures of body size or composition correlated with LM-proportional W MAX or VO2 MAX in girls or boys. Only LM correlated positively with height-proportional W MAX (r = 0.65) and VO2 MAX (r = 0.71) in boys. FM correlated negatively with weight-proportional W MAX (r < -0.58) and VO2 MAX (r < -0.64) in girls and boys. FM was even stronger determinant of weight-proportional W MAX (β = -0.68) and VO2 MAX (β = -0.61) than exercise performance in multivariate linear regression models.

CONCLUSIONS

While assessing cardiorespiratory fitness, LM is the most appropriate measure of body size or composition for scaling of W MAX and VO2 MAX, because scaling by body weight introduces confounding by body adiposity.

Predição da potência aeróbia (VO2máx) de crianças e adolescentes em teste incremental na esteira rolante

O consumo máximo de oxigênio (VO2máx) é a quantidade máxima de energia que pode ser produzida pelo metabolismo aeróbio em determinada unidade de tempo, podendo ser determinado direta ou indiretamente através de equações preditivas. O objetivo deste trabalho foi elaborar uma equação preditiva específica para determinar o VO2máx de meninos de 10 a 16 anos. Quarenta e dois meninos realizaram teste ergoespirométrico de corrida em esteira rolante com velocidade inicial de 9 km/h até exaustão voluntária. Através da regressão linear múltipla foi possível desenvolver a seguinte equação para a determinação indireta do VO2máx: VO2máx (ml/min) = -1574,06 + (141,38 x Vpico) + (48,34 * Massa corporal), com erro padrão de estimativa = 191,5 ml/min (4,10 ml/kg/min) e o coeficiente de determinação = 0,934. Sugerimos que esta é uma fórmula adequada para predizer o VO2máx para esta população.

Aerobic capacity and exercise performance in young people born extremely preterm

OBJECTIVES

The goal of this study was to compare aerobic capacity and exercise performance of children and adolescents born extremely preterm and at term, and to relate findings to medical history and lifestyle factors. Potential cohort effects were assessed by studying subjects born in different decades.

METHODS

Two area-based cohorts of subjects born with gestational age ≤28 weeks or birth weight ≤1000 g in 1982-1985 and 1991-1992 and matched control subjects born at term were compared by using standardized maximal treadmill exercise and pulmonary function tests. Background data were collected from questionnaires and medical records.

RESULTS

Seventy-five of 86 eligible preterm subjects (87%) and 75 control subjects were assessed at mean ages of 17.6 years (n = 40 + 40) and 10.6 years (n = 35 + 35). At average, measures of aerobic capacity for subjects born preterm and at term were in the same range, whereas average running distance was modestly reduced for those born preterm. Leisure-time physical activity was similarly and positively associated with exercise capacity in preterm and term-born adolescents alike, although participation was lower among those born preterm. Neonatal bronchopulmonary dysplasia and current forced expiratory vol in 1 second was unrelated to exercise capacity. Differences between subjects born preterm and at term had not changed over the 2 decades studied.

CONCLUSION

Despite their high-risk start to life and a series of potential shortcomings, subjects born preterm may achieve normal exercise capacity, and their response to physical training seems comparable to peers born at term.

Exercise metabolism during moderate-intensity exercise in children with cystic fibrosis following heavy-intensity exercise

Muscle metabolism is increased following exercise in healthy individuals, affecting exercise metabolism during subsequent physical work. We hypothesized that following heavy-intensity exercise (HIE), disease factors in children with cystic fibrosis (CF) would further exacerbate exercise metabolism and perceived exertion during subsequent exercise. Nineteen children with CF (age, 13.4 ± 3.1 years; 10 female) and 19 healthy controls (age, 13.8 ± 3.5 years; 10 female) performed 10 bouts of HIE interspersed with 1 min of recovery between each bout. Three minutes later participants completed a 10-min moderate-intensity exercise (MIE) test (test 1). The MIE test was subsequently repeated 1 h (test 2) and 24 h (test 3) later. Each MIE test was identical and participants exercised at individualized work rates, calibrated by an initial graded maximal cardiopulmonary exercise test, while metabolic and perceived exertion measurements were taken. Following HIE, mixed-model ANOVAs showed a significant difference in oxygen uptake (VO2) and rating of perceived exertion (RPE) between the 2 groups across the MIE tests (p < 0.01). In controls, VO2 (L·min–1) and RPE decreased significantly from test 1 to test 2 (p < 0.01) and test 2 to test 3 (p < 0.05). However, in children with CF, VO2 (L·min–1) increased significantly from test 1 to test 2 (p < 0.01), while RPE did not differ, both VO2 and RPE decreased significantly from test 2 to test 3 (p < 0.01). In conclusion, following HIE the metabolic and perceptual responses to MIE in both groups decreased 24 h later during test 3. These data show that children with mild-to-moderate CF have the capability to perform HIE and 24 h allows sufficient time for recovery.

Cardiopulmonary exercise testing in congenital heart disease: (contra)indications and interpretation

Cardiopulmonary exercise testing (CPET) in paediatric cardiology differs in many aspects from the tests performed in adult cardiology. Children's cardiovascular responses during exercise testing present different characteristics, particularly oxygen uptake, heart rate and blood pressure response, which are essential in interpreting haemodynamic data. Diseases that are associated with myocardial ischaemia are rare in children. The main indications for CPET in children are evaluation of exercise capacity and the identification of exercise-induced arrhythmias. In this article we will review the main indications for CPET in children with congenital heart disease, the contraindications for exercise testing and the indications for terminating an exercise test. Moreover, we will address the interpretation of gas exchange data from CPET in children with congenital heart disease. (Neth Heart J 2009;17:385-92.).

Integrative gaming: a framework for sustainable game-based diabetes management

Obesity and diabetes have reached epidemic proportions in both developing and developed nations. While doctors and caregivers stress the importance of physical exercise in maintaining a healthy lifestyle, many people have difficulty subscribing to a healthy lifestyle. Virtual reality games offer a potentially exciting aid in accelerating and sustaining behavior change. However, care needs to be taken to develop sustainable models of employing games for the management of diabetes and obesity. In this article, we propose an integrative gaming paradigm designed to combine multiple activities involving physical exercises and cognitive skills through a game-based storyline. The persuasive story acts as a motivational binder that enables a user to perform multiple activities such as running, cycling, and problem solving. These activities guide a virtual character through different stages of the game. While performing the activities in the games, users wear sensors that can measure movement (accelerometers, gyrometers, magnetometers) and sense physiological measures (heart rate, pulse oximeter oxygen saturation). These measures drive the game and are stored and analyzed on a cloud computing platform. A prototype integrative gaming system is described and design considerations are discussed. The system is highly configurable and allows researchers to build games for the system with ease and drive the games with different types of activities. The capabilities of the system allow for engaging and motivating the user in the long term. Clinicians can employ the system to collect clinically relevant data in a seamless manner.