Editor’s note: The following excerpt comes from FM 21-20: Physical Readiness Training, an Army field manual published in 1969. It makes a note to soldiers in more administrative positions that they will need to do make-up workouts when their more active brethren are out on maneuverers: “If your assignment is such that you are ‘chairborne’ during the time your unit is participating in vigorous field training, you will require a supplementary individual program to maintain your physical fitness.” As part of this supplementary training, doing isometrics around the office is suggested. The exercises below take less than 15 minutes to perform, and are not only useful for the military “chairborne,” but for civilian desk jockeys who wish to flex their muscles a little over the course of an otherwise sedentary day.
Isometric Principle and Procession
The isometric principle is to apply force gradually over a 5- to 10-second period until the maximum application is applied. Relaxation follows for approximately 5 seconds and then force is applied. This process continues until the prescribed dosage, as indicated for each exercise, is complete.
Doorframe Exercises
The following exercises are designed for use with a standard doorframe found in all offices or barracks.
a. Exercise 1, Arm Press
Stand in the doorway with the legs straight, knees locked. Using your arm muscles, press hard upward against the top of the doorframe. Repeat for three repetitions applying gradual effort to maximum contraction.
b. Exercise 2, Leg Press
Stand in the doorway with the hands on the top of the doorframe, elbows locked. With your knees bent, press hard with your leg muscles. Repeat for three repetitions beginning with a gradual effort and increasing to maximum contraction. A low platform may be necessary to reach the top of the doorframe and still maintain a bent knee position.
c. Exercise 3, Side Press
Extend both arms to the side of the doorway. Palms are shoulder high, facing outward. With both arms, press hard against the sides of the doorframe. Repeat for three repetitions. Begin gradually and increase to maximum contraction.
d. Exercise 4, Lateral Raise
Extend both arms to the sides of the doorway, arms down, palms facing inward. With the back of the hands, press hard against the sides of the doorframe. Repeat for three repetitions. Begin with a gradual effort and increase to maximum contraction.
e. Exercise 5, Neck Press
Place your forehead against the doorframe, hands clasped behind the back. Using your neck muscles, press hard against the doorframe. Repeat for three repetitions, then reverse your position so that the back of the head is resting on the doorframe. Again for three repetitions. Begin gradually with both exercises and increase to maximum contraction.
f. Exercise 6, Door Pull
Stand facing the edge of the open door and grasp the doorknobs. Pull outward with both arms (if doorknobs are not available grasp the edge of the door). As you apply outward pressure, move the body toward and way from the door. Repeat for three repetitions. Begin with gradual effort and increase to maximum contraction.
Isometrics at the Desk
The following exercises are designed for use while sitting at a desk or table.
a. Exercise 1, Arm Press
Place the arms on the top of the desk, palms down. Press downward with the arm muscles. Begin gradually and increase to your maximum effort. Repeat for three repetitions.
b. Exercise 2, Chair Lift
Grasp the bottom of the chair seat with both hands. Pull upward with the arm muscles. Begin gradually and increase to your maximum effort. Repeat for three repetitions.
c. Exercise 3, Desk Lift
Place the hands under the desk, palms up. Lift upward with the arms muscles. Begin gradually and increase to your maximum effort. Repeat for three repetitions.
d. Exercise 4, Leg Raiser
Lift the legs until the toes touch the inside top of the desk. Using the leg muscles, press upward with the toes. Begin gradually and increase to your maximum effort. Repeat for three repetitions.
e. Exercise 5, Abdominal Contractions
Contract the stomach muscles and hold at maximum effort for 10 seconds. Relax for 5 seconds, then repeat for three repetitions. Repeat this procedure for both inward and outward contractions.
f. Exercise 6, Neck Contractions
Fold the arms, lean forward, and place them on the desk top. Bow the head, placing the forehead on your arms. Using the neck muscles, apply downward pressure. Begin gradually and increase to maximum effort.
