This week's 25-minute full-body HIIT exercise is sure to make you sweat SHEFIT’s Brand Ambassador Karrah demonstrates a three-circuit workout that starts by focusing on your core, then going into arm and leg workouts. Try to concentrate on form this time. It may seem small, but proper form ensures that you get the most out of your exercise without risk of injury! 

Karrah is wearing The Ultimate in Ambition, $69. 

Circuit 1: 3 Rounds

Alternating Straddle Steps (40 seconds)

Stand upright next to one long side of a flat bench. You should be perpendicular to the bench. From the starting position, raise the foot near the bench and place it on top of the bench. Push off the bench with the raised foot, changing feet in mid-air, so that you land on the opposite side of the bench with your other foot now on top and your landing leg slightly bent. Continue alternating for 40 seconds. 

5 Walking Lunges with Oblique Twists

Begin standing with your feet shoulder width apart and a barbell across your upper back. Step forward with your left leg, flexing the knees to drop your hips. Descend until your rear knee nearly touches the ground. Your posture should remain upright, and your front knee should stay above the front foot. Twist at the waist and rotate to your left, rotate back to the center and drive through the heel of your lead foot and extend both knees to raise yourself back up. Step forward with your rear foot, repeating the lunge on the opposite leg. 

10 Barbell Crunches 

Lie on your back, holding a barbell using an overhand grip (shoulder width apart). Extend your arms above you, raising your upper body off the ground and keep your lower back secure. Bend your knees and bring them to your chest. Hold for a moment and return to the starting position. 

Circuit 2: 3 Rounds

Knee Drives (40 seconds)

Stand facing a box or bench of an appropriate height with your feet together. Begin the movement by stepping up, putting your left foot on the top of the bench. As you stand on the box with your left leg, flex your right knee, jumping and bringing it up as high as you can. Reverse this motion to step down off the box, and repeat the sequence on the opposite leg. 

10 Good Mornings

Stand with your feet shoulder-width apart and rest a light barbell across the back of your shoulders (not your neck), holding it with both hands. Stand upright, brace your core and pull your shoulders back. Take a breath and hinge forwards from your hips, not your waist, allowing a slight bend in your knees but keeping your back flat. Lean forward until you feel a slight stretch in your hamstrings (but don't go beyond horizontal), then, as you exhale, reverse the move to stand up straight. 

10 Curls 

Stand up with your torso upright while holding a barbell at a shoulder-width grip. The palm of your hands should be facing forward and the elbows should be close to the torso. While holding the upper arms stationary, curl the weights forward while contracting the biceps as your breathe out. Continue the movement until your biceps are fully contracted and the bar is at shoulder level. Hold the contracted position for a second and squeeze the biceps hard. Slowly begin to bring the bar back to starting position as your breathe in. Repeat. 

Circuit 3: 3 Rounds

Pop Squats (40 seconds)

Position your legs using a wider-than-shoulder-width stance with the toes slightly pointed out and knees slightly bent. Keep your neck neutral and maintain a straight back. Descend into a squat by pushing your hips and butt backwards. Continue down until the upper legs are at or just below parallel to the floor. Inhale as you perform this portion of the movement. Once you reach your bottom position, begin to push through your heels to ascend upwards. Generate enough power to jump upwards bringing both feet inward towards one another so that you land with your feet a few inches apart. Make sure to land on your toes with your feet close together, immediately propel yourself upwards and jump to return to the starting position. Repeat. 

10 Alternating Lateral Lunges 

Set up with your feet shoulder width apart and a barbell resting across your traps. Step laterally with your trail leg extended and descend until the thigh is parallel with the floor. Drive through the weight bearing leg and extend the knee as you push back to the starting position. Repeat on the opposite leg. 

10 Plank Pull Throughs 

Begin in a full plank position with a dumbbell OR weight on the floor a few inches away from the outside of right hand. Engage abs to keep torso steady and reach left arm under right to grab the weight. Pull the weight across the floor to the left side of your body, releasing it just outside of your left arm, and then return to plank. That's one rep.