Manini TM, Newman AB, Fielding R, Blair SN, Perri MG, Anton SD, Goodpaster BC, Katula JA, Rejeski WJ, Kritchevsky SB, Hsu FC, Pahor M, King AC. Effects of exercise on mobility in obese and nonobese older adults. Obesity (Silver Spring). 2010 Jun; 18(6):1168-75.