Doing crunches until the cows come home? Stop it! When you're down to your final inches of belly fat, the dreaded crunch won't be the exercise that finally reveals your six-pack. "You can't spot reduce," Jill says. Instead, she suggests doing functional exercises that use the muscles in your core—abdominals, back, pelvic, obliques—as well as other body parts. "These exercises use more muscles, so there is a higher rate of calorie burn while you are doing them," she says. Planks are her favorite functional exercise—they activate not just your core muscles but also your arm, leg, and butt muscles.
The Nike Run Club app, however, is the star of the show. Each Nike watchface has dedicated complications for launching the app and a tally of your last run (or a guilty nag if you haven't hit the pavement for a while). Once you're in the NRC app, it's a simple thing to start a run or download one of the guided runs (including the ever-expanding library of Run with Headspace workouts, my favorites).