But just because you aren’t showing off your abs, doesn’t mean that their existence isn’t on your mind. Fortunately, a few changes to your routine can make all the difference. When you shock your body with a new exercise regimen, you may start seeing results in as little as one to two weeks.

The unique benefit of this routine is that you can do it when you’re short on time. The circuit format will also help keep your heart rate up to burn more calories and fat, and the variety of moves will challenge even the most advanced exerciser.

Perform this routine in a circuit, completing one set of each exercise before moving on to the next, with little to no rest. Catch your breath, then repeat the circuit one or two more times. Since you’ll definitely feel the after-effects the next day, do this workout twice a week, with recovery time in between.

Obliques Bench Crunch:

Target Muscles: internal and external obliques, rectus abdominis

How to:

  • Lie faceup on the floor and rest your lower legs on a bench or chair.
  • Place your fingertips lightly behind your head for support.
  • As you exhale, contract your abs to lift your shoulders from the floor and twist one elbow towards your opposite knee.
  • Inhale as you return to the center, lower back down to the floor, then come up and twist to the other side.
  • Continue alternating for your set.

Related article: 7 Body Weight Exercises That Will Change Your Body In 28 Days

Reverse Crunch:

Target Muscles: transverse abdominis, rectus abdominis

How to:

  • Lie on your back with your arms at your sides, palms down.
  • Lift your feet and bend your knees to 90 degrees.
  • Exhale as you contract your abs and lift your hips several inches off the floor, directing your knees towards your chest.
  • Slowly return to the starting position and repeat.

Related article: Speed Up Your Metabolism With These Super 5 Fat-Burning Foods

Side Plank with Overhead Raise:

Target Muscles: rectus abdominis, internal and external obliques

How to:

  • Grab a dumbbell in your left hand and lie on your right side with your legs extended.
  • Prop yourself up on your right forearm, and stack your feet so the inner edges touch.
  • Lift your hips up away from the floor to bring your body into a straight line from your head to your heels.
  • Move your left arm in an arc until the weight is directly above your shoulder, then lower with control.
  • Complete all reps before switching sides.

Related article: If You Want A Six Pack Fast Then These 3 Exercises Are Great To Give You Just That

Single-Legged Plank:

Target Muscles: transverse abdominis, erector spinae, gluteus maximus

How to:

  • Begin on all fours.
  • Place your elbows on the floor directly under your shoulders, then extend your legs behind you and lift up onto your toes.
  • Raise one leg from the floor and hold for 30 seconds.
  • When finished, return to the starting position and repeat with your opposite leg.

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Weighted Windmill:

Target Muscles: internal and external obliques

How to:

  • Stand with your feet wider than shoulder-width apart, with toes turned out slightly.
  • Hold a dumbbell in your left hand and extend both arms out to the sides at shoulder height.
  • Inhale as you bend to the right side, reaching your right hand to the outside of your foot and raising your left arm overhead.
  • Exhale as you return to standing.
  • Complete all your reps, then move the dumbbell to your right hand and repeat on the other side.