Get a Body Like Blake Lively

No one would say Blake Lively ever looked anything short of amazing, but after getting into superhero-worthy shape for her role in 'The Green Lantern', her body is insane! Her secret? Celebrity trainer Bobby Strom’s circuit workouts. "This was new for her-Blake had never done a regimented routine with a trainer before," says Strom. "Believe it or not her body began to change in only three weeks!"

All you need is a set of 5-8 pound dumbbells and a swiss ball. Lively worked out five times a week, but "if you only have time to put in three days a week, make sure it's high intensity (push the weight and repetitions to your maximum comfort level) and you'll still get results," says Strom, who emphasizes pairing any routine with a healthy diet (Lively added fresh vegetable juices and lean protein to hers). "Minor diet tweaks and healthy, conscious eating will get you faster, better results."

• Sit on a swiss ball with the small of your back supporting your weight on the ball and legs bent at a 90 degree angle in front of you. Then, holding a five-pound weight with both hands, place it behind your head and perform 15-20 crunches.

• Lie on your back and place feet shoulder-width apart on the swiss ball. Keep your back flat and arms at your sides. Slowly lift your hips, making a straight line from your chest to your knees and return. Repeat 15-20 times.

• On your stomach, keeping your core muscles tight and engaged, hold plank for 60 seconds, relax and repeat 10 times.

• Perform 20 squats with eight-pound dumbbells in each hand. Make sure your back is straight and knees don't reach out past your toes (like you're sitting in a chair).

• With the same dumbbells, perform 10 reverse lunges on each leg. Make sure to maintain good posture and keep your core muscles engaged.

• Keep your arms at your sides with five-pounds dumbbells in each hand. Perform 20 squat jumps.

Tip: If the weight is too challenging, complete the first week with just body weight. Then, add a few pounds each week until you reach the recommended amount.

• Perform 15 bicep curls on each arm with an eight-pound dumbbell. When you're used to the weight, try standing on one leg, do 15 right arm curls on the opposite arm and switch. This extra challenge will engage your core and leg muscles while you tone your arms.

• Using five-pound dumbbells, bend at the waist until your upper body is parallel to the floor and perform 15 tricep kickbacks on each arm.

• Hold five-pound dumbbells in each hand, palms facing in, arms at your side. Slowly lift the weights with straight to shoulder level and return. To also engage your core and leg muscles, stand on one leg with your knee slightly bent for eight repetitions, switch legs and repeat.

Rest as needed and repeat entire core, legs and arms circuit two more times.