For years, researchers scoffed at the idea that swimming affected bone mass. After all, only weight-bearing exercises were able to achieve this benefit, right? Not according to research published in the Journal of Applied Physiology. Because there are ethical reasons to avoid in-depth bone examination on humans, the study put rats into three groups: running, swimming, and a control group with no exercise stimulation. While running still showed the highest increase in BMD (Bone Mineral Density),[1] the swimming group also showed benefits over the control group in both BMD and femoral bone weight. While more studies are needed, these new findings show that previous research dismissing swimming’s bone benefits may need to be revisited.