Use this six-minute abdominal exercise circuit to target and tone all of the muscles of your abdomen: internal and external obliques, transversus abdominis and rectus abdominis. If you don't see visible results within two to four weeks, consider shedding belly fat, which blankets your stomach like a heavy coat and conceals muscle development . Reducing your body fat percentage through careful attention to nutrition and high-intensity aerobic interval training will reveal six-pack abs even faster. Perform the circuit every day with one to two rest days each week.
Perform isometric contractions with planks and side planks for one minute. Hold the basic plank position for 10 seconds, then kick each leg behind you and bring your knee into your chest alternating between legs for another 20 seconds. For the remainder of the first minute, rotate and hold a side plank for 15 seconds on each side. To increase the challenge of the side plank, raise the top leg and hold for one second. Ensure that your body forms a straight line and your hips do not sag in any of the plank positions.
Roll over onto your back and perform these exercises in quick succession for two minutes: vertical leg crunch and reverse crunch. A study commissioned by the American Council on Exercise found these exercises 216 and 240 percent more effective, respectively, at recruiting the oblique muscles than the basic crunch.
Target your abdominal muscles from a slightly different angle by performing twisting exercises such as the bicycle maneuver and the Pilates scissor exercise for two minutes. The ACE study found the bicycle maneuver 248 percent more effective at recruiting the rectus abdominis than a basic crunch and a whopping 290 percent more effective at recruiting the oblique muscles.
Train your spinal erectors for the final minute in your circuit with supermans and stability ball knee tucks and pikes. Include spinal erector training in your abdominal workouts to support proper posture and a balanced core.