The Navy SEAL Physical Fitness Guide 139
Another change that should be incorporated in an abdominal
workout is the addition of a 2 inch thick towel or an “Ab Mat” beneath
the lower spine. The anatomical range of motion for the abdominals is from 30 ̊
extension to approximately 75-90 ̊ flexion (Figure 8-3). When performing abdominal
exercises on a flat surface (i.e., the deck) you are limiting your exercise to only half the
normal abdominal range of motion. In other words, when abdominal exercises are
performed on a floor, deck, or mat, only half the work necessary to develop abdominal
strength is being done. Abdominal strength is best developed by exercises performed
within the full anatomical range of motion, with some curve in the lumbar spine (i.e., towel
or Ab Mat) as opposed to a flat back. By placing a towel or the Ab mat beneath your lower
spine you can achieve the right form for these exercises (see Figure 8-4).
Figure 8-3. Range of
Motion for Flexion and
Extension of the Upper
Body Based on
Anatomy
Figure 8-4. Placing a
Towel Beneath the Lower
Spine can Help Achieve the
Right Form for Abdominal
Exercises
Because of limited flexibility, it is better
to start abdominal exercises at approximately
15 ° of extension and eventually work toward
30 ° extension. A towel is particularly useful because you can adjust it to provide inclines
of 15° and 30°.
Recommendations for Sit-Ups
In recent years, the sit-up technique has undergone many modifications. Because
sit-ups compose a large portion of the SEAL training program, some specific comments
regarding their proper use are crucial.
When performing sit-ups, the preferred technique is to bend the legs at the hips (at
45 °) with the feet flat on the deck shoulder width apart. Legs should be slightly abducted
(turned outward). If hands are placed behind the head, care should be taken not to force the
FlexionExtension(30°)(75° TO 90°)Neutral
(0°)Towel