To do kick-outs using correct form, sit on the floor with your upper body angled back no more than 45 degrees and your arms extended behind you with your palms flat on the floor. Extend your legs in front of you with your feet together, the soles of your feet on the floor and your knees bent roughly 90 degrees. Begin the exercise by leaning your torso back, lifting your feet off the floor and pulling your knees toward your upper chest. This is your starting position. Kick out by extending your legs completely, keeping them off the floor, and pointing your toes toward the ceiling. Lean your torso back as you kick out, but keep your back above the floor -- your body should resemble a severely flattened V-shape when your legs and torso are both extended. Return to the starting position, then continue for your desired number of repetitions.
Kick-out exercises can be used as part of a kickboxing or martial arts workout, for obvious reasons, because the exercise employs a kicking motion. For non-kickboxers, the kick-out exercise begins strengthening your lower abdominal muscles from the moment your feet leave the floor and continues to work them until your set is complete. The activity also works the quadriceps muscles on the front of each thigh.
You can do kick-outs as stand-alone exercises or make them part of an overall abdominal session. The American Council on Exercise recommends that you perform a five-minute daily ab routine that includes several exercises. Among the best exercises to complement kick-outs are bicycle crunches, the captain’s chair exercise and reverse crunches, all of which work your rectus abdominis and oblique muscles. As a beginner, perform at least five kick-outs, but try to work up to three sets of 15 repetitions. Alternatively, try to do as many kick-outs as you can in a 30-second or one-minute span.
Consult a doctor before starting a new exercise routine, particularly if you’ve been inactive or have any health concerns. Stop doing kick-outs if you feel pain. Warm up before you exercise by doing five to 10 minutes of light cardio activity. Stretch your muscles dynamically before doing kick-outs. For example, loosen your abs by performing at least 10 standing trunk rotations, and stretch your quads by walking with long strides.