Swimming Could Be Better for Your Heart Than Running — Here’s Why

Swimming and running both improve aerobic fitness, but a new Brazilian study suggests they may reshape the heart differently. When researchers matched the two activities for duration and relative intensity, swimming produced stronger structural, functional and molecular changes.

The result does not prove that swimming protects human hearts better or that runners should change sports. The experiment involved young male rats, making it an important biological clue rather than clinical guidance for people.