California girl Montag loves a beach workout. "Beach training can be a very nice way to get motivated to exercise, with the chance to be outside in a beautiful, relaxing environment," says Dr. Kenton Fibel, sports medicine physician at the Cedars-Sinai Kerlan-Jobe Institute. "A potential benefit of beach training can be to strengthen the foot and ankle muscles, as well as the stabilizers of other joints. Sand is a surface that does not have the same stability and predictability as other surfaces. For this reason, this uneven—and sometimes unstable—surface can lead to injury. If you do not typically exercise, this could end up being too aggressive of an activity. Wearing shoes may be helpful."