"I train biceps and triceps on the same day," says the 23-year-old. "I feel I can best focus on my arms by training them in one workout a week. I've always done that."

Jessica—who became an IFBB professional figure competitor at age 20—typically trains biceps before triceps for about nine working sets per muscle group. She keeps things moving by using relatively short rest periods, about one minute between sets.

"I usually start with biceps, but sometimes I know my body needs something different, so I'll change things up and train my triceps first just to shock the muscles."

You'll find Jessica's off-season workout on these pages. When she's preparing for a contest, she supersets her exercises—meaning she performs two exercises back to back without resting in between. Noncompetitors can do this, too: It's a great way to get through your workout more quickly and burn more calories in the process. You can pair two biceps moves or even a biceps exercise with a triceps movement, supersetting them the same way. hers