In obese adults aged 65 and older undergoing approximately 10% weight loss through dietary intervention, resistance exercise or combined aerobic and resistance exercise reduces hip bone mineral density loss by 70-80% compared to aerobic exercise alone over six months, with hip bone mineral density decreasing by 0.7% and 1.1% versus 2.6% respectively.

When older obese adults lose weight, their fat tissue shrinks and releases less leptin, which causes more bone breakdown. Resistance exercise puts stress on the hip bones, which tells bone cells to reduce a signal that normally promotes bone loss. This stress also helps maintain leptin levels, which keeps another signal that stops bone breakdown from rising. Together, these effects slow down the cells that eat away bone, so the hip doesn't lose as much density.