The plank jack is a bodyweight exercise that adds a jumping jack movement pattern to the [standard plank](https://www.masterclass.com/articles/plank-guide) exercise. Perform plank jacks by starting in a high plank position with your hands shoulder-width apart beneath you. Keep your upper body and lower body in a straight line as you jump your feet out and back. Plank jacks are a total-body home workout, activating your lower back muscles, leg muscles, arm muscles, and core muscles simultaneously. With proper form, this plank variation can increase your heart rate, burn calories, and build your core strength. For plank jacks, begin by performing 2–3 sets of 30–60 seconds or 10–20 repetitions. Choose your length of time or number of repetitions based on your ability to maintain good technique throughout all sets and repetitions. 1. Get into the all-fours position with your knees and toes flexed and in contact with the floor. Your hips should be over your knees. Your hands should be slightly wider than your shoulders. 2. Grip the ground with your hands and rotate your shoulders outward to engage your lats. 3. Straighten your legs to lift your knees off of the ground so you end up in a pushup position. Your legs should be no wider than hip-width apart. 4. Pre-tension your shoulders and hips while engaging your core. Squeeze your quads and glutes. Your chin should remain tucked throughout the movement as if you were holding an egg under your chin. All repetitions should begin from this position. 5. While maintaining your alignment, jump your feet outside of your shoulders, then jump your feet back to the starting position. 6. Quickly repeat this movement as if you were performing a horizontal jumping jack. 7. Continue for the desired number of repetitions or length of time. If you have a previous or pre-existing health condition, consult your physician before beginning an exercise program. Proper exercise technique is essential to ensure the safety and effectiveness of an exercise program, but you may need to modify each exercise to attain optimal results based on your individual needs. Always select a weight that allows you to have full control of your body throughout the movement. When performing any exercise, pay close attention to your body, and stop immediately if you note pain or discomfort. In order to see continual progress and build body strength, incorporate proper warm-ups, rest, and nutrition into your exercise program. Your results will ultimately be based on your ability to adequately recover from your workouts. Rest for 24 to 48 hours before training the same muscle groups to allow sufficient recovery. Throw on some athleisure, fire up a [MasterClass Annual Membership](https://www.masterclass.com), and get ready to sweat it out with exclusive instructional videos from Nike Master Trainer and *GQ* fitness specialist Joe Holder. Want to improve your cardiovascular endurance? Give Joe’s HIIT workout a go. Trying to get a little swole? He’s got a strength training workout for that. From fitness tips to nutrition hacks, Joe will have you feeling healthier in no time. If you want to include more cardio in your strength-training program, try a full-body workout like the plank jack.