Pediatric Exercise Testing: Value and Implications of Peak Oxygen Uptake

Effect of exercise on postoperative recovery of patients with non-small cell lung cancer: a systematic review and meta-analysis

Patients with non-small cell lung cancer (NSCLC) in the postoperative recovery period often experience reduced exercise capacity and impaired lung function, which affects their overall quality of life. This paper investigated the effect of exercise interventions on exercise capacity, lung function, quality of life, and symptoms in these patients.

METHODS

We performed a literature search across Cochrane, Embase, PubMed, Web of Science, and EBSCO databases were comprehensively searched for randomized controlled trials (RCTs) from inception to September 2023, all English RCTs were eligible if they assessed the effects of exercise interventions on postoperative NSCLC patients.

RESULTS

Twelve articles met our inclusion criteria, evidencing that exercise interventions could significantly improve the functional capacity of NSCLC patients in postoperative recovery. Notably, Forced Expiratory Volume in 1 s (FEV1) was improved, indicating enhanced lung function. Furthermore, exercise improved the physical and mental health scores of SF-36, along with increased quadriceps strength and relieved dyspnea. However, fatigue levels were not significantly changed.

CONCLUSIONS

Exercise interventions of NSCLC patients in the postoperative recovery are associated with improved functional capacity, lung function, quality of life, and quadriceps strength, as well as alleviated symptoms of dyspnea. These findings underscore the potential benefits of incorporating exercise into postoperative care for NSCLC patients. Nonetheless, further large-scale RCTs are required to solidify the evidence base on the clinical outcomes of exercise following pneumonectomy.

A Comparison of Warm-Up Effects on Maximal Aerobic Exercise Performance in Children

The aim of this study was to compare the warm-up effects of treadmill walking (TW) with a dynamic (DY) bodyweight warm-up on maximal aerobic exercise performance in children. Sixteen children (10.9 ± 1.5 vrs) were tested for peak oxygen uptake (VO₂ peak) on 2 nonconsecutive days following different 6 min warm-up protocols. TW consisted of walking on a motor-driven treadmill at 2.2 mph and 0% grade whereas the DY warm-up consisted of 9 body weight movements including dynamic stretches, lunges, and jumps. Maximal heart rate was significantly higher following DY than TW (193.9 ± 6.2 vs. 191.6 ± 6.1 bpm, respectively; p = 0.008). VO₂ peak (54.8 ± 9.6 vs. 51.8 ± 8.7 mL/kg/min; p = 0.09), maximal minute ventilation (68.9 ± 14.8 vs. 64.9 ± 9.4 L/min; p = 0.27), maximal respiratory exchange ratio (1.12 ± 0.1 vs. 1.11 ± 0.1; p = 0.85) and total exercise time (614.0 ± 77.1 vs. 605 ± 95.0 s; p = 0.55) did not differ significantly between DY and TM warm-ups, respectively. These findings indicate that the design of the warm-up protocol can influence the heart rate response to maximal aerobic exercise and has a tendency to influence VO₂ peak. A DY warm-up could be a viable alternative to a TW warm-up prior to maximal exercise testing in children.

US School-Based Physical Fitness Assessments and Data Dissemination

BACKGROUND

Low physical fitness (PF) levels during childhood affect healthy growth and development, and increase the risk of cardiovascular diseases. Physical education standards exist for nearly all states in the United States, but evaluation of PF in youth has yet to be systematic, reproducible, and harmonized. The purpose of this project was to describe publicly available data of school-based PF testing (SB-PFT).

METHODS

A list of state-mandated SB-PFT programs published by SHAPE 2016 was confirmed by contacting appropriate authorities. SB-PFT data were obtained through each state's department of education.

RESULTS

Sixteen states mandate SB-PFT, with 10 states providing publicly available data; 92% to 100% of states perform the pacer/mile, curl-up, and push-up; 54.2% to 78.5% of elementary and 44% to 66.5% of high-school youth are in the "healthy fitness zone" for aerobic capacity.

CONCLUSIONS

SB-PFT provided PF data in children across the United States. The variability and inconsistency in reporting and in the values, however, raises questions about the current status of SB-PFT data and its utility in assessing PF in children. The critical nature of PF assessments is highlighted in the current COVID-19 pandemic, during which physical education has been curtailed, and emerging data demonstrate worsening of the already low levels of PF in youth.

Effect of high-intensity interval training in adolescents with asthma: The eXercise for Asthma with Commando Joe's® (X4ACJ) trial

BACKGROUND

Higher levels of cardiorespiratory fitness are associated with reduced asthma severity and increased quality of life in those with asthma. Therefore, the purpose of this study was to evaluate the effectiveness of a 6-month high-intensity interval training (HIIT) intervention in adolescents with and without asthma.

METHODS

A total of 616 adolescents (334 boys; 13.0 ± 1.1 years, 1.57 ± 0.10 m, 52.6 ± 12.9 kg, mean ± SD), including 155 with asthma (78 boys), were recruited as part of a randomized controlled trial from 5 schools (4 control and 1 intervention). The 221 intervention participants (116 boys; 47 asthma) completed 6 months of school-based HIIT (30 min, 3 times per week, 10-30 s bouts at >90% age-predicted maximum heart rate with equal rest). At baseline, mid-intervention, post-intervention, and 3-month follow-up, measurements for 20-m shuttle run, body mass index (BMI), lung function, Pediatric Quality of Life Inventory, Paediatric Asthma Quality of Life Questionnaire, and Asthma Control Questionnaire were collected. Additionally, 69 adolescents (39 boys (of the 36 with asthma there were 21 boys)) also completed an incremental ramp test. For analysis, each group's data (intervention and control) were divided into those with and without asthma.

RESULTS

Participants with asthma did not differ from their peers in any parameter of aerobic fitness, at any time-point, but were characterized by a greater BMI. The intervention elicited a significant improvement in maximal aerobic fitness but no change in sub-maximal parameters of aerobic fitness, lung function, or quality of life irrespective of asthma status. Those in the intervention group maintained their BMI, whereas BMI significantly increased in the control group throughout the 6-month period.

CONCLUSION

HIIT represents an effective tool for improving aerobic fitness and maintaining BMI in adolescents, irrespective of asthma status. HIIT was well-tolerated by those with asthma, who evidenced a similar aerobic fitness to their healthy peers and responded equally well to a HIIT program.

Bicycle spiroergometry: comparison of standardized examination protocols for adolescents: is it necessary to define own standard values for each protocol?

Purpose

To compare performance data of adolescents collected with five different bicycle spiroergometry protocols and to assess the necessity for establishing standard values for each protocol.

Methods

One-hundred-twenty adolescents completed two bicycle spiroergometries within 14 days. One of the two tests was performed based on our institutional weight-adapted protocol (P0). The other test was performed based on one out of four exercise protocols widely used for children and adolescents (P1, 2, 3 or 4) with 30 persons each. The two tests were performed in a random order. Routine parameters of cardiopulmonary exercise tests (CPET) such as VO₂peak, maximum power, O₂ pulse, OUES, VE/VCO₂ slope as well as ventilatory and lactate thresholds were investigated. Agreement between protocols was evaluated by Bland–Altman analysis, coefficients of variation (CV) and intra-class correlation coefficients (ICC).

Results

None of the CPET parameters were significantly different between P0 and P1, 2, 3 or 4. For most of the parameters, low biases between P0 and P1–P4 were found and 95% confidence intervalls were narrow. CV and ICC values largely corresponded to well-defined analytical goals (CV < 10% and ICC > 0.9). Only maximal power (Pmax) showed differences in size and drift of the bias depending on the length of the step duration of the protocols.

Conclusion

Comparability between examination protocols has been shown for CPET parameters independent on step duration. Protocol-dependent standard values do not appear to be necessary. Only Pmax is dependent on the step duration, but in most cases, this has no significant influence on the fitness assessment.

A new approach to estimate aerobic fitness using the NHANES dataset

INTRODUCTION

Physical activity and fitness are essential for healthy growth in children. The National Health and Nutrition Examination Survey (NHANES) evaluated fitness by estimating V̇O2 max from submaximal measurements of heart rate (HR) during graded treadmill exercise. Our aims were (a) to examine how well NHANES methodology used to estimate V̇O2 max correlated with actual VO2 max and (b) to evaluate a novel fitness metric using actual data collected during exercise and its relationship to physical activity and sedentary time, lipid profiles, and body composition.

METHODS

Fifty-three adolescents completed NHANES submaximal exercise protocol and maximal graded cardiopulmonary exercise testing. We used a novel approach to quantifying fitness (Δvelocity × incline × body mass (VIM)/ΔHR slopes) and evaluated its relationship to physical activity and sedentary time using NHANES data (n = 4498). In a subset (n = 740), we compared ΔVIM/ΔHR slopes to NHANES estimated V̇O2 max and examined their relationship to cardiovascular risk factors (BMI percentiles and lipid levels).

RESULTS

Measured V̇O2 peak was moderately correlated with NHANES estimated V̇O2 max (r = 0.53, P < 0.01). Significantly higher ΔVIM/ΔHR slopes were associated with increased physical activity and decreased sedentary time. ΔVIM/ΔHR slopes were negatively associated with LDL, triglycerides, and BMI percentiles (P < 0.01). In general, the two fitness models were similar; however, ΔVIM/ΔHR was more discriminating than NHANES in quantifying the relationship between fitness and LDL levels.

CONCLUSION

We found that the NHANES estimated V̇O2 max accounted for approximately 28% of the variability in the measured V̇O2 peak. Our approach to estimating fitness (ΔVIM/ΔHR slopes) using actual data provided similar relationships to lipid levels. We suggest that fitness measurements based on actually measured data may produce more accurate assessments of fitness and, ultimately, better approaches linking exercise to health in children.

Measurement and Interpretation of Maximal Aerobic Power in Children

The assessment of maximal aerobic power ( V˙O2max ) in both children and adults is an invaluable tool for the evaluation of exercise performance capacity and general physical fitness in clinical, athletic, public health, and research applications. The complexity of means and considerations, as well as varying specific aims of V˙O2max testing, has prevented the formulation of a universally applicable, standard testing protocol, in general, and for children in particular. Numerous tester-controllable factors, such as exercise modality, metabolic measurement system, testing protocol, or data reduction strategies, can affect both the measurement and interpretation of V˙O2max data. Although the general guiding principles are similar, children differ from adults in several aspects. One notable difference is the frequent absence of a discernible V˙O2 plateau in children. Thus, the proper choice of equipment and procedures may be different for children than for adults. It is therefore the aim of this article to highlight the general and pediatric-specific considerations that may affect V˙O2max measurement and interpretation of results.

Validity of equations for estimating aerobic fitness in Mexican youth

The purpose of this study was to evaluate the validity of prediction equations for estimating maximal oxygen uptake (VO_2peak) based on the PACER test and different adiposity indicators in Mexican youth. A convenience sample of youth aged 9-18 years from schools in Mexico City was recruited. VO_2peak was evaluated with a laboratory exercise test on a treadmill and using a gas analyser and with the 20-m PACER test guidelines. The sample was randomly divided to develop new equations (n = 220) and to evaluate their validity (n = 106). Prediction equations of VO_2peak were developed using multiple linear regression models. The adiposity indicators were BMI, waist circumference and body fat. The validity of the new and previously published equations was evaluated based on linear regression models, intra-class coefficient, Akaike's information criterion, mean absolute percentage error and Bland-Altman graphs. Equations with waist circumference and body fat performed better than those with BMI and without any anthropometric indicator. The accuracy of the developed equations (R² = 57.0%-59.50%) was higher than that of previously published equations (R² = 24.1%-56.0%). The new equations had lower bias in estimating VO_2peak. In Mexican youth, the estimation of VO_2peak from the 20-m PACER test is more accurate after including waist circumference or body fat than with BMI.

Commentary on the Assessment and Interpretation of Pediatric Aerobic Fitness-The Year That Was 2017

Three papers, which between them contribute to the current debate on the assessment and interpretation of pediatric aerobic fitness, were selected for commentary. The first paper (Children. 2017; 4:6; doi: 10.3390/children4010006 ) highlights the merits of clinical exercise testing and advocates the advancement of pediatric exercise testing through a rationale founded on demonstrated prognostic value of data obtained. It notes the lack of well-accepted definitions of exercise outcome variables in children and promotes the case for data harmonization across laboratories. The second paper (J Appl Physiol. 2017; 122: 997-1002) argues persuasively that the acceptance of peak oxygen uptake (peak [Formula: see text]) at the termination of an exercise test to voluntary exhaustion as a surrogate for a "true" maximal value (ie, [Formula: see text]) is no longer tolerable. The authors present a compelling case for the adoption of a follow-up verification test to unambiguously validate the achievement of [Formula: see text]. The third paper (Br J Sports Med. 2017; 1-10, doi: 10.1136/bjsports-2017-097982 ) compiles large, previously published datasets to provide a review of temporal trends in 20-m shuttle run test scores. The authors assert that temporal trends in 20-m shuttle run test performance provide meaningful insight into trends in population health. The commentary stresses the importance of scientific rigor in pediatric exercise testing, emphasizes the use of precise definitions when describing health-related variables, and cautions against the misuse of exercise outcome measures in recommendations relating to or impacting on young people's health and well-being.

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.