When many people hear the term calisthenics, they often think of high school gym or military boot-camp. While exercise options have expanded to include equipment and other forms of movement, calisthenics continue to be an effective total body workout. Further because it relies on your body for resistance, you don't need equipment or much space, which makes calisthenics portable and affordable.
One of the reasons calisthenics are so effective is that they work more than one muscle at a time. One of the the best total body exercises is the squat thrust, also called the burpee. This move increases the heart rate to improve cardiovascular health, and strengthens the core, legs, shoulders and arms. Stand upright with your legs shoulder width apart. Squat down reaching your hands to the floor. Jump both feet back until you're in a plank position. Do a pushup and then jump your feet back towards your hands and stand up. You can do a set number such as 20 or time yourself for 30 seconds to a minute. To modify the exercise you can use a step aerobic bench for the plank and push up. You can also step the feet up and back instead of jumping them. For safety, keep your hands under or in line with your shoulders while in the plank and pushup positions, and don't let your back sag during the transition from the squat to the plank or during the pushup.
Like the squat thrust, mountain climbers work multiple parts of the body including the heart. Start on all-fours on the floor with your hands directly under your shoulders. With the balls of the feet on the floor, extend one leg back. It should look and feel like you're about to start a race. Jump your feet and have them switch positions, pulling the back one up towards the chest and extending the opposite one back. Do this back and forth at a brisk pace. Make sure you keep your shoulders over your hands and that your hands are flat on the floor. You can modify mountain climbers by having your hands on a step bench. You can also step your feet back and forth instead of jumping.
Plyometric exercises add a cardiovascular workout to your strength training. For example, squats are a traditional part of calisthenic exercises. You can add cardio benefits by doing a squat jump. Do a squat as you normally would, but instead of standing up, jump up. You can add jumps to lunges as well. Lunge forward or back on one leg, jump and switch the leg positions so that the opposite leg is forward when you land. In both these examples you're building leg and core strength while adding cardiovascular strength as well.
The best calisthenic exercise for upper body that doesn't involve weights or a pullup bar is the pushup. One way to change the intensity and the muscles worked in the pushup is to change the position of your hands. The closer your hands are to each other, the more challenging the pushup. For greater challenge, rest your feet on a chair, which puts more weight over your arms. One arm pushups not only maximize the workout for each arm, but also work the core more to help keep you balanced.