These exercises strengthen the muscles on the sides of the abdomen and the lower part of the back, and are an excellent means to reduce the size of the waist in case of corpulency. =Exercises for the Muscles of the Back= (Fig. 51).—These exercises may be taken lying prone on the floor, with the feet caught under any piece of furniture which is strong and low enough to act as a cross-bar, as a lounge or dressing case. No one but an athlete could take this exercise without having the feet held down. The feet should be held firmly down, and the hands may be at the sides or clasped behind the waist; the body is then slowly raised and carried backward to the half-sitting posture, then gradually lowered to the original position. These movements should be taken slowly and not repeated more than five times in the beginning. In case of stooping or round shoulders, the hands should be clasped at the back of the neck instead of at the waist. Raise the head and extend the spine, pressing the elbows backward. This exercise is a severe one on the extensors of the back and the rotators of the shoulders. =Exercises for the Muscles of the Abdomen= (Fig. 52).—Lie supine on the floor, with the feet firmly fixed under a cross bar, or a piece of furniture which will answer this purpose, and the hands resting on the hips, as shown in the figure; slowly raise the body to the upright position, maintain for a moment, and return to the first position. This and the preceding exercise are both excellent for strengthening the abdominal muscles and reducing an excessive accumulation of fat in case of obesity of this region. [Illustration: Fig. 51.—Exercises for muscles of back.] [Illustration: Fig. 52.—Exercises for muscles of abdomen.] [Illustration: Fig. 53.—Swimming exercises: for back, thighs, and abdomen. First position.] [Illustration: Fig. 54.—Swimming exercises: for back, thighs, and abdomen. Second position.] [Illustration: Fig. 55.—Rope-pulling exercises: for back, chest, waist, legs, and arms. First position.] [Illustration: Fig. 56.—Rope-pulling exercises: for back, chest, waist, legs, and arms. Second position.] [Illustration: Fig. 57.—Exercises in lateral trunk flexions: for shoulders, chest, hips, and legs. First position.] =Swimming Exercises: for Back, Thighs, and Abdomen= (Figs. 53, 54).—_First Position._—The movements given here are those for the breast-stroke in swimming. Stand with the feet about eighteen inches apart, with the right foot advanced and the right leg straight; the weight is thrown on the left leg, and the arms bent at right angles, ready for the beginning of the stroke, as shown in the pose. _Second Position._—Shoot the arms directly forward, incline the whole body forward, straighten the left leg, and throw the weight on the right, which should be bent, as shown in the second pose. Then sweep the hands and arms outward in a horizontal plane, until the arms, trunk, and legs are brought into the original position.