Australian Instagram sensation, personal trainer and author of Bikini Body Guide, Kayla Itsines has one of the hottest bods around. The 26-year-old's enviably trim and sculpted physique makes for one seriously aspirational #fitselfie, but what's even more impressive are the before and after pictures of her clients.

Try this quick exercise routine she has specially put together for Shape, and watch yourself tone up within weeks.

Do all exercises in these three circuits within seven minutes.

You may follow the number of repetitions recommended, or do as many as you can, so long as you maintain good form. Take a 60-second break between each circuit.

CIRCUIT 1: WORKS FULL BODY

Do 20 reps of snap jumps, 100 skips and 50 ab bikes. You will need a skipping rope, mat and timer.

1. SNAP JUMP

Start in push-up position: Get on all fours and place both hands on floor slightly wider than shoulder-width apart with feet together behind you, while resting on balls of feet. Transfer body weight onto hands and jump feet inwards to land in crouched position with feet directly behind or slightly outside hands. Kick feet backwards into starting push-up position, while maintaining neutral spine. Stabilise body using abdominal muscles. This counts as one rep.

2. SKIPPING

Form check: Make sure you land on balls of your feet with knees slightly bent. Each time you jump over the rope counts as one skip.

3. AB BIKE

Start by laying flat on back on yoga mat with feet extended in front of you. Lift both legs so they hover slightly above ground. Bring left leg in towards chest and twist upper body so right elbow meets left knee. Repeat on other side. Each individual twist counts as one rep.

CIRCUIT 2: WORKS LOWER BODY

Do 20 reps of sumo jump squats, 10 burpee and tuck jumps, and 30 reverse lunge and knee lifts (15 each side). You will need a timer.

1. SUMO JUMP SQUAT

Plant both feet wider than shoulder-width apart with feet pointed outwards. Ensuring knees point towards toes, bend them until thighs are parallel to floor in sumo squat position. Pushing through heels, propel body upwards into air in one explosive motion. Extend legs mid-air, and land softly into sumo squat position to complete rep.

2. BURPEE + TUCK JUMP

Once in push-up position on floor, transfer weight onto hands and jump feet inwards towards hands. As you stand, propel body upwards and bring knees in towards chest. Take care to land softly without locking knees. Bend at hips and knees to place hands on floor in front of you, and jump feet backwards to return to push-up position to complete rep.

3. REVERSE LUNGE + KNEE LIFT

Plant both feet on floor slightly wider than shoulder-width apart and carefully take one step backwards with right foot. As you plant right foot, bend both knees at 90-degree angle, ensuring weight is evenly distributed between both legs. Then, extend both legs and transfer weight completely onto left foot. Lift right foot and bring tight knee in towards chest. Lower right knee, place right foot back on floor behind you, and bend both knees at 90-degree angle. Do 15 reps (or as many as you can manage) on right before switching to left.

CIRCUIT 3: WORKS UPPER BODY

Do 20 toe taps, 50 X-mountain climbers (25 each side) and 15 lay down push-ups. You will need a yoga mat and a timer.

1. TOE TAP

Start by lying flat on yoga mat with arms extended above head. Carefully raise legs off floor so they create 90-degree angle with hips. Engage abdominals by drawing belly button in towards spine. Using abdominals, slowly lift head, shoulder blades and torso off floor to bring hands to toes. Squeeze upper abdominals before slowly lowering torso backwards and extending arms behind head, reclining into starting position, to complete rep.

2. X-MOUNTAIN CLIMBER

Place both hands on floor slightly further than shoulder-width apart with feet together behind you. Keeping left foot on floor, bend right knee and bring right leg in towards chest and left elbow. Extend right leg and return to starting position. Repeat with left leg. Continue between left and right, gradually increasing speed as if running on hands. Ensure wrists remain in line with shoulders at all times and body forms one straight line from head to toe. Each leg movement equals one rep.

3. LAY DOWN PUSH-UP

Start by lying flat on stomach with arms extended out in front of you, and legs straight behind you with feet slightly apart. Turn toes in towards floor. Bring arms in towards body and position hands on either side of chest. Push through chest and extend arms to lift body into push-up position. Maintain neutral spine and stabilise body using abdominals throughout entire movement. Slowly lower body completely to floor and extend arms out in front of you to complete rep.

•This article first appeared in www.shape.com.sg