The Claim
Twelve-year-old endurance athletes exhibit higher stroke volume and left ventricular end-diastolic volume relative to fat-free mass compared to non-endurance-trained peers.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Twelve-year-old endurance athletes have larger heart chamber sizes and more blood pumped per heartbeat relative to their lean body mass than other children their age who do not train in endurance sports.
See the scientific wording
Twelve-year-old endurance athletes have higher stroke volume and left ventricular end-diastolic volume relative to fat-free mass than non-endurance-trained peers, suggesting greater cardiac adaptation in this group.
Repeated endurance exercise causes more blood to return to the heart during activity, which stretches the heart's main pumping chamber, making it hold more blood and pump out more with each beat, even after accounting for muscle mass.
What the research says
1 studyKids who train hard in endurance sports like cross-country skiing have bigger heart chambers and pump more blood with each heartbeat compared to kids who don't train, even when you account for how much muscle they have.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.