Maximal cardiac output in athletes: influence of age.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of cross-sectional observational studies
PubMed 25595549 · doi:10.1177/2047487314566759
What was done
A systematic review and meta-analysis of MEDLINE, Cochrane, and Web of Science (inception to June 2014) evaluated maximal cardiac output (Qmax) in endurance-trained athletes (EA) compared with age-matched untrained healthy subjects. Included studies had groups matched for body size or presented Qmax normalized to body size. Subgroup comparisons evaluated young EA (mean age ≤40 years) versus master EA (mean age >55 years), and meta-regression tested the moderating effects of age and body fat differences.
What was found
Eighteen studies were included, comprising 268 EA and 232 untrained subjects across 9 young and 9 master athlete studies. Both young and master EA had higher Qmax than controls (standardized mean difference [SMD] = 1.49 and SMD = 1.68, respectively; both p < 0.0001), with no significant difference between the two age tiers (p = 0.61). The SMD in VO2max between EA and controls also showed no difference between young and master cohorts (p = 0.37). In meta-regression, the difference in body fat percentage was inversely associated with SMD in Qmax (B = -0.17, p = 0.01) and SMD in VO2max (B = -0.20, p = 0.01). Mean age was not associated with SMD in Qmax (B = -0.001, p = 0.90) or SMD in VO2max (B = 0.01, p = 0.58).
Why it matters
This review demonstrates that the central hemodynamic advantage of endurance exercise persists into older age relative to sedentary peers, suggesting that accelerated VO2max declines in athletes are not primarily driven by an exaggerated loss of maximal cardiac output.
Limits
All included studies were cross-sectional rather than longitudinal. The overall sample was modest (500 total participants across 18 studies). The study design excluded or did not capture individuals aged 41 to 54 years, and potential heterogeneity in cardiac output measurement techniques across studies was not detailed.
Cited by
- supports Elite endurance athletes can achieve maximal cardiac outputs of 40 liters per minute.