Decline Bench Crunch

EXECUTION

• Position the bench at a decline of approximately 30-40° from the horizontal. Secure the feet between the upper or under lower rollers depending upon the type of bench you are using.
• Lie with your trunk, shoulders and head in full contact with the bench and with the hands crossed on the chest.
• Inhale and hold your breath as you curl up the head and shoulders only.
• Curl up as much as possible flexing the thoracic spine only. Hold the upper most position for a moment or two and then exhale and return under control to the initial position.
• Be sure the shoulders and head come to rest on the bench before attempting the next repetition.
• In the beginning position, you should be looking up at the ceiling and in the ending position, after curling upward, you should be looking toward the feet.

TRAINING TIPS

• When first starting to do the decline bench crunch, start with the bench at a slight angle to the horizontal (approximately 10°). Gradually increase the angle as you become accustomed to the exercise.
• Angling the bench down beyond a 40-45° angle is not recommended. In the down position, excessive amount of blood collects in the upper body and especially in the head. The increased blood pressure in the head may be dangerous especially if you have weakened blood vessels.
• To increase the amount of resistance, place your hands behind the head and execute in exactly the same manner. Concentrate on curling the shoulders up, not the head.
• If you desire less resistance, use a smaller angle of decline and/or hold the arms alongside the body as you curl up. The more you place the hands toward the upper body or over the head, the greater is the resistance.
• Because of the decline position and because the feet are secured, the hip flexors must come into action to stabilize the pelvis and thus, allow you to do the exercise effectively. This is not dangerous since contraction of the hip flexors makes the exercise safer and more effective.
• Even though this exercise targets more of the upper abs, the lower abs still undergo contraction, but not shortening. The entire abdominal wall is under contraction along with the hip flexors during execution.
• Be sure to curl the head and shoulders up off the bench. Do not raise the head and shoulders straight upward toward the ceiling. This detracts from a full contraction of the upper abdominals and may activate the lower back muscles.
• Be sure to return to the initial position with the head and shoulders on the pad. If you keep the abdominals under contraction and the spine rounded on each repetition, the muscles will shorten to such an extent that you will become round shouldered and develop what is known as the hunchback or dowagers hump condition.
• It is important that you inhale and hold your breath on the exertion as you raise the head and shoulders. The breath holding makes you stronger so that you can go through the full range of motion and it helps to stabilize the spine to prevent injury.

MAJOR MUSCLES INVOLVED

The abdominal muscle group which includes the rectus abdominis, external oblique and internal oblique is involved in the crunch. The rectus abdominis is a long, slender muscle running vertically across the abdomen from the lower ribs to the pelvic bone. The fibers run parallel to one another and are crossed by three tendonous intersections, which provide the divisions seen in a person with well-developed and defined musculature.

The external oblique muscle covers the sides and front of the abdomen from the rectus abdominis to the latissimus dorsi muscles. The fibers run diagonally upward and sideward from the lower attachment on both sides of the abdomen and form the letter “V”.

The internal oblique is located directly underneath the external oblique. Its fibers run at nearly right angles to the external oblique, forming an inverted “V” (At the lower end, close to the pubis, the fibers are almost horizontal, but gradually become more angled as you move upward toward the ribs).

The hip flexors (rectus femoris, iliopsoas and pectineus) are also involved but only as stabilizers. The rectus femoris is located on the length of the anterior thigh and the iliopsoas is located deep in the abdomen. The pectineus is a small muscle located on the inner front side of the hip joint.

JOINT AND MUSCLE ACTIONS

In the decline bench crunch exercise, the upper abdominal muscles contract and shorten to flex the thoracic spine. In this action the shoulders move toward the lower body. The lower abdominals also undergo contraction but do not shorten or cause movement as they stabilize the lower abdomen. The hip flexors undergo an isometric contraction to stabilize the pelvis.

SPORTS USES

For bodybuilders, the decline bench crunch is extremely important for full development of the upper abdominals, especially for muscle definition and the “ripped” appearance. Because this exercise stresses mainly the upper abs and movement occurs in the thoracic spine, not much benefit transfers to other sports in which the athlete must flex the spine in the lumbar area. However, it is still of benefit to athletes who must perform a baseball pitch, football pass, tennis serve and overhead, javelin throw, soccer throw-in, and other sports that require overhead throwing and hitting. It is also important for gymnasts, acrobats, divers, wrestlers and martial art performers in execution of many skills and stunts but not as much as the 45°-60° sit-up.