This bike-run plan will tone your thighs and leave fat in the dust.

Your mission You can push past that voice that says, “I want to stop” or “This workout’s too hard”—just channel your inner competitor. With this duathlon-inspired plan, you’ll split your time between a bike and a treadmill, “racing” yourself for 15 minutes on each machine. Thanks to speed intervals and challenging inclines, this workout burns up to 12 calories a minute. Plus, you’ll be strengthening your legs and butt. There may not be a crowd cheering you on at this finish line, but you’re guaranteed to win a prize: A slimmer, sexier body. See you at the medal stand!