Fitness moves are best done effectively in pairs. "Doing two moves at the same time—each targeting an opposing or unrelated muscle group—allows you to train harder without exhausting a single group too quickly," says certified personal trainer Katrina Hodgson, CEO and cofounder of ToneItUp.com and Tone It Up fitness studio in Los Angeles, who created this workout. "This method of training also boosts total-body tone and helps sidestep muscular imbalances that can lead to injuries."

These moves not only benefit your exercise, they get you out of the gym in half the time!

Do this 20-minute workout about three times a week on alternate days. You'll need a pair of dumbbells at about 5 to 8 pounds, and a balance ball. Do each exercise without resting in between. Once you're done with all the 8 moves, rest for a minute or two, then repeat the workout three more times.

Women's Health magazine shares this video tutorial: