United States calisthenics is a type of exercise consisting of a variety of simple movements usually performed without weights or other equipment that are intended to increase body strength and flexibility using the weight of one's own body for resistance. The history of calisthenics is linked to gymnastics. Disciples of Friedrich Ludwig Jahn brought their version of gymnastics to the United States, while Catherine Beecher and Dio Lewis set up physical education programs for women in the 19th Century. Organized systems of calisthenics in America took a back seat to competitive sports after the Battle of the Systems during which states mandated physical education systems.
Examples of calisthenic exercises include:
Sit-ups/crunches: Start with your back on the floor, knees bent, bottoms of feet against the floor. Lift shoulders off the floor by tightening abdominal muscles bringing your chest closer to your knees. Lower back to the floor with a smooth movement.
Push-ups: Start face down on floor, palms against floor under shoulders, toes curled up against floor. Push up with arms keeping a straight line from head through toes. Lower to within a few inches off floor and repeat. You should keep your head tilted upward, your back straight. Do not rest on your shoulder blades, even when you feel fatigue.
Squats: Stand with feet shoulder width apart. Squat as far as possible bringing your arms forward parallel to the floor. Return to standing position. Repeat. Again, if you feel like this is not a challenge, there are other forms of squats. One method is lifting one leg off the floor in front of you, putting both arms in front of you for balance, and squatting. This is a one-legged squat or pistol. Squats are deemed by many health experts to be unsafe, because they put too much stress on the knee joints.