A person who weighs 150 pounds burns about 2 calories for each push-up. This varies based on individual differences. The calorie count for heavier people is a bit more, while lighter exercisers burn slightly less.
Push-ups primarily work the chest and triceps. When using correct form, however, the exercise also engages core, hip and leg muscles, and the body moves as one unit. The exertion comes from the upper body, and hips do not shift out of alignment during the raising or lowering stage. To maintain continual exertion, the chest never rests on the floor. The lowest position for the chest is 2 to 3 inches above the floor. If a full-body push-up is initially too difficult, the exercise should be done from the knees.