Cardiorespiratory fitness and health in children and adolescents: an overview of systematic reviews with meta-analyses representing over 125 000 observations covering 33 health-related outcomes

Abstract

Objective: To synthesise data on the associations between cardiorespiratory fitness (CRF) and health in children and adolescents, evaluate the certainty of evidence and identify knowledge gaps.

Design: An overview of systematic reviews with meta-analyses. Results were pooled using forest plots and certainty of evidence evaluated with GRADE.

Data sources: Medline, Embase, Scopus, CINAHL and SPORTDiscus were searched from January 2002 to March 2024.

Eligibility criteria for selected studies: Systematic reviews with meta-analyses exploring CRF and health in children and adolescents aged <18 years.

Results: From the 9062 records identified, 14 reviews were included. Meta-analysed data from 125 164 observations covering 33 health outcomes were compiled, showing favourable (n=26) or null (n=7) associations with CRF. Among general populations, the associations were weak-to-moderate, with favourable links between CRF and indicators of anthropometry and adiposity, cardiometabolic and vascular health, and mental health and well-being. Among clinical populations, CRF was lower in participants with a condition compared with healthy controls, with the largest difference for newly diagnosed cancer (mean difference=-19.6 mL/kg/min; 95%CI: -21.4,-17.8). Patients with cystic fibrosis had a greater risk for all-cause mortality when comparing low CRF vs. high (relative risk=4.9; 95%CI: 1.1, 22.1). The certainty of evidence ranged from very low to moderate.

Conclusion: CRF shows promising links to numerous health outcomes in paediatric populations, though the low certainty of evidence calls for further research. High-quality longitudinal evidence is warranted to confirm the findings and investigate a predictive role of childhood CRF for future health.

Keywords: Health; Pediatrics; Physical fitness.

Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow chart illustrating the number of articles identified, screened and included in the overview. Notes: ^aA list of excluded articles with reasons is provided in online supplemental eAppendix 2.

Figure 2. Linear correlations between cardiorespiratory fitness and health outcomes in children and adolescents. Notes: all outcomes are presented for the general population, except HbA1c. ^aData are for the clinical population of children and adolescents with type 1 diabetes. ^bLongitudinal evidence was prioritised over cross-sectional for GRADE assessment. BF%, body fat percentage; BMI, body mass index; CI, confidence interval; DBP, diastolic blood pressure; HbA1c, glycated haemoglobin; HDL-C, high-density lipoprotein cholesterol; HOMA-IR, homeostatic model assessment for insulin resistance; I², heterogeneity index; LDL-C, low-density lipoprotein cholesterol; MetS, metabolic syndrome; r, correlation coefficient; SBP, systolic blood pressure; TC, total cholesterol; TC:HDL, total cholesterol to HDL-C ratio; WC, waist circumference.

Figure 3. Mean differences between cardiorespiratory fitness in clinical populations of children and adolescents vs healthy controls. Notes: ^aMeasured by V̇O₂peak corrected for lean tissue mass. CHD, congenital heart disease; CI, confidence interval; HIV, human immunodeficiency virus; JIA, juvenile idiopathic arthritis; I², heterogeneity index; MD, mean difference; NR, not reported.