correlational
Analysis v1
Strong Support
Runners who train harder and faster for years tend to have bigger heart chambers than those who run less, which helps their hearts pump more blood.
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Evidence from Studies
Supporting (1)
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Community contributions welcome
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The study found that elite amateur runners have bigger heart chambers than casual runners, which means their hearts have grown bigger over time from training hard — just like the claim says.
Contradicting (0)
0
Community contributions welcome
No contradicting evidence found
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.