Association of Cardiorespiratory Fitness Levels During Youth With Health Risk Later in Life: A Systematic Review and Meta-analysis

Key PointsQuestionIs cardiorespiratory fitness associated with future health benefits in children and adolescents? FindingsThis systematic review and meta-analysis of 55 studies that included 37563 youths revealed that cardiorespiratory fitness levels and change over approximately 1 year during youth were associated with lower risk of developing obesity and cardiometabolic disease later in life. These early associations detected from baseline to follow-up dissipated over time. MeaningThe study suggests that prevention strategies that target youth cardiorespiratory fitness may be associated with improved health parameters in later life. ImportanceAlthough the associations between cardiorespiratory fitness (CRF) and health in adults are well understood, to date, no systematic review has quantitatively examined the association between CRF during youth and health parameters later in life. ObjectivesTo examine the prospective association between CRF in childhood and adolescence and future health status and to assess whether changes in CRF are associated with future health status at least 1 year later. Data SourcesFor this systematic review and meta-analysis, MEDLINE, Embase, and SPORTDiscus electronic databases were searched for relevant articles published from database inception to January 30, 2020. Study SelectionThe following inclusion criteria were used: CRF measured using a validated test and assessed at baseline and/or its change from baseline to the end of follow-up, healthy population with a mean age of 3 to 18 years at baseline, and prospective cohort design with a follow-up period of at least 1 year. Data Extraction and SynthesisData were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effects models were used to estimate the pooled effect size. Main Outcomes and MeasuresAnthropometric and adiposity measurements and cardiometabolic health parameters. ResultsFifty-five studies were included with a total of 37563 youths (46% female). Weak-moderate associations were found between CRF at baseline and body mass index (r=-0.11; 95% CI, -0.18 to -0.04; I-2=59.03), waist circumference (r=-0.29; 95% CI, -0.42 to -0.14; I-2=69.42), skinfold thickness (r=-0.34; 95% CI, -0.41 to -0.26; I-2=83.87), obesity (r=-0.15; 95% CI, -0.23 to -0.06; I-2=86.75), total cholesterol level (r=-0.12; 95% CI, -0.19 to -0.05; I-2=75.81), high-density lipoprotein cholesterol (HDL-C) level (r=0.11; 95% CI, 0.05-0.18; I-2=69.06), total cholesterol to HDL-C ratio (r=-0.19; 95% CI, -0.26 to -0.13; I-2=67.07), triglyceride levels (r=-0.10; 95% CI, -0.18 to -0.02; I-2=73.43), homeostasis model assessment for insulin resistance (r=-0.12; 95% CI, -0.18 to -0.06; I-2=68.26), fasting insulin level (r=-0.07; 95% CI, -0.11 to -0.03; I-2=0), and cardiometabolic risk (r=-0.18; 95% CI, -0.29 to -0.07; I-2=90.61) at follow-up. Meta-regression analyses found that early associations in waist circumference (beta =0.014; 95% CI, 0.002-0.026), skinfold thickness (beta =0.006; 95% CI, 0.002-0.011), HDL-C level (beta=-0.006; 95% CI, -0.011 to -0.001), triglyceride levels (beta =0.009; 95% CI, 0.004-0.014), and cardiometabolic risk (beta =0.007; 95% CI, 0.003-0.011) from baseline to follow-up dissipated over time. Weak-moderate associations were found between change in CRF and body mass index (r=-0.17; 95% CI, -0.24 to -0.11; I-2=39.65), skinfold thickness (r=-0.36; 95% CI, -0.58 to -0.09; I-2=96.84), obesity (r=-0.21; 95% CI, -0.35 to -0.06; I-2=91.08), HDL-C level (r=0.05; 95% CI, 0.02-0.08; I-2=0), low-density lipoprotein cholesterol level (r=-0.06; 95% CI, -0.11 to -0.01; I-2=58.94), and cardiometabolic risk (r=-0.08; 95% CI, -0.15 to -0.02; I-2=69.53) later in life. Conclusions and RelevanceThis study suggests that early intervention and prevention strategies that target youth CRF may be associated with maintaining health parameters in later life. This systematic review and meta-analysis examines the prospective association between cardiorespiratory fitness in childhood and adolescence and health status later in life.