How Swimming and Running Affect the Heart Differently
Researchers from Brazil's Federal University of São Paulo (UNIFESP) have discovered that swimming and running impact the heart at a molecular level in distinct ways, even though both activities improve endurance. Swimming triggers deeper structural changes in the heart and activates molecular mechanisms that running does not.
Led by Professor Andre Jorge Serra and supported by the FAPESP foundation, the study was published in Scientific Reports. Using a mouse model, the team divided subjects into three groups: no exercise, running, and swimming. The training program lasted eight weeks, with 60-minute sessions five times per week. Exercise intensity was measured via VO₂ max, which increased by over 5% in both active groups.
Key Findings from the Research
A significant discovery was that only the swimming group showed a statistically meaningful increase in total heart mass and left ventricular mass. No such structural changes were observed in the running group. The researchers noted that swimming induces stronger shifts in microRNAs, which play a crucial role in heart adaptation by regulating messenger RNA expression. In contrast, the running group exhibited weaker effects on microRNAs.
'Swimming and running are both excellent ways to improve cardiorespiratory health and protect the heart muscle, but we wanted to find out if one could be even more beneficial than the other.' - Professor Andre Jorge Serra
The researchers emphasize that choosing a sport largely depends on personal preference, physical ability, and enjoyment. While this remains a valid argument, the new findings from Brazilian scientists challenge the conventional equivalence between swimming and running. As Andre Jorge Serra noted:
'Although several studies have already examined the expression of microRNAs regulated by aerobic training in general, little was known about the patterns of this expression when directly comparing swimming and running within the same experimental model.' - Professor Andre Jorge Serra
Based on these results, it can be concluded that while both forms of physical activity benefit the cardiovascular system, their effects at the molecular level may differ.
This research underscores the importance of choosing the right type of exercise, as outcomes can vary depending on the activity. Swimming appears to offer greater heart benefits at the molecular level compared to running, which could be significant for those aiming to improve their cardiorespiratory health. These findings may inspire further studies in sports physiology and help develop more effective training programs.
Legal disclaimer. This article provides general reference information and should not be considered a substitute for medical advice.
The recent findings on the distinct heart benefits of swimming compared to running highlight the importance of re-evaluating our understanding of exercise recommendations. As scientists continue to uncover the nuances of physical activity's impact on health, updated guidelines on protein and activity may be necessary to reflect these insights and optimize heart health strategies.