The use of resistance training for development of strength and endurance of specific muscle groups has long been a part of physical conditioning. Muscle response to short duration, heavy load exercise is called anaerobic conditioning.
Anaerobic conditioning, like aerobic conditioning, does not increase G-tolerance, but both increase the ability to sustain the AGSM needed to offset the effects of G-loads. Both aerobic and anaerobic training produce G-tolerance benefits through conditioning the neuromuscular system. However, due to the many variables associated with physical training, both aerobic and anaerobic, it is difficult to determine an effective program. The following are some parameters that apply to strength training programs in general.
Basically, strength training utilizes two modes of exercise: isotonic and isometric. Isotonic exercise uses muscle force to produce movement, whereas isometric exercise uses muscle force but no movement. In addition, there is concentric and eccentric training. Producing muscle force as muscle shortens is concentric; in contrast, maintaining force while the muscle lengthens is eccentric. The coordination needed for control inputs to fly aerobatics requires a balance between these two types of muscle contractions.
To improve muscle strength and endurance, it is necessary to overload the muscle. This is done by the repetition-set system. A repetition is a single movement of the weight or resistance; a set is a certain number of repetitions. Combined with this repetition-set system, muscle force is applied against resistance. The resistance overload can be in the form of free weights or weight machines. With these parameters in mind, an anaerobic conditioning program for the sport aerobatic pilot can be recommended.
To fly aerobatics does not require a high strength level, but instead, a fine control of concentric and eccentric muscle contractions. In addition, repeated isometric contractions are needed, not only to counter the effects of G-loads on blood flow to the brain, but also to support the pilot s body against the loads.
Even though the torso is strapped tightly in the airplane, muscles in the shoulders, chest, and back contract isometrically to stabilize the body during periods of G-load stress. Such stabilization is critical for support of the head. This is done automatically, without conscious thought. Muscles in the arms and legs contract isometrically to support the extremities against both positive and negative G-loads. This, too, requires no thought process. These muscle contractions are short in duration but, because of repetition, place demands on both muscle strength and endurance.
With these demands in mind, consider the specifics of an anaerobic conditioning program for the aerobatic pilot. Remember, for optimum results, training must be specific for a sport activity.
The use of weight machines is not recommended conditioning for aero-baric flight. While such devices permit isotonic overload for a specific muscle group, little demand is placed on the balance system. By contrast, free weights not only exercise the balance mechanism, but also require use of more muscles for body stability, the same situation found under G-load stress. Despite being strapped in with the harness system, muscles in the body are used to stabilize the pilot as the G-loads fluctuate. Free weights help develop the total body control and coordination needed to counter the effects from the wide variety of G-loads experienced by the aerobatic pilot.
To achieve anaerobic improvement, a muscle must be stressed beyond the level at which it is accustomed to working. Traditionally, the program for weight training has been six to eight repetitions with a given weight load, two to three sets, three times per week. Once this load can be tolerated easily, the amount of weight can be increased. As mentioned, the human neuromuscular system adapts to this exercise program in approximately six to eight weeks. Thus, to avoid regression or staleness, it is necessary to implement different overloads. The pyramid system is one method of varying workload.
The pyramid system of overload has several variations that work well for the aerobatic pilot. One variation is to use a number of sets in which the weight increases as the sets progress while the repetitions per set decreases. A second is to start with few repetitions and heavy weight, then increase the repetitions with less resistance for subsequent sets. A third is a combination- increasing resistance to a maximum and then backing down again, varying sets and repetitions as the resistance changes. Each of these variations can be used for two to three weeks. There must be at least 48 hours between each workout to avoid overstress; muscles must be allowed to recover from the stress of a workout.
If a strength program is stopped, 50 percent of the gain will be lost in five weeks and, with resumption of training, strength level will return in 10 weeks. The greatest decline will be in the first 10 to 14 days; however, as little as one workout per week will maintain the same level.
For the military pilots G-load profile with long-duration G-loads, muscles of the extremities, particularly the legs, are a major component of AGSM. The sport aerobatic pilot, however, must use the arm and leg muscles for control inputs needed to fly the figures. This is done under positive and negative G-loads that fluctuate in magnitude and duration. Not only are the muscle demands being made under G-loads, but the muscles must function to produce fine movements of the controls required by the complexity of the aerobatic figures. Therefore, the aerobatic pilot does not have the benefit of isometric muscle contractions in the arms and legs as a means to counter G-loads.
For the aerobatic pilot, the abdominal muscles are the single most important muscle group for countering the G-load profile experienced in sport aerobatics. Over the years, I have studied the effectiveness of isometric contraction of the abdominal muscles to counter short-duration, high-magnitude G-loads combined with rapid alterations between positive and negative loads. Consequently, I developed an AGSM technique that I called the squeeze maneuver.
Biomechanically, the abdominal muscles are the single most important muscle group for countering G-loads. Large veins in the abdominal cavity act as blood reservoirs, largely unsupported by muscle and capable of holding a significant quantity of blood. Compression of this cavity with abdominal muscles counters the effect of G-loads. This requires a sudden, explosive isotonic contraction of the abdominal muscles so as to compress the abdominal contents against the spine. This contraction is then held isometrically for the duration of the G-load so as to keep the intra-abdominal pressure elevated.
Through experimentation I found the squeeze maneuver very effective for use with the sport aerobatic G-load profile. It frees up the muscles of the arms and legs to make the needed contractions for control movements required by the aerobatic figures.
The traditional type of AGSM used by the military requires the pilot to strain as if trying to have a bowel movement. Not so with the squeeze maneuver. Instead, the pilot sucks in the rectum as if trying not to have a bowel movement, while at the same time contracting the abdominal muscles as if trying to make the waist as small as possible.
While the abdominal muscles do not lend themselves to a wide variety of strength training techniques, the following program is specific for sport aerobatics. First, learn the technique by contracting the abdominal muscles so as to squeeze the abdomen tightly for approximately 10 seconds; then relax and repeat. During this contraction do not hold the breath.
Second, once the squeeze technique is learned, use it as part of mental practice. When mentally practicing an aerobatic sequence with imagery, perform the squeeze in coordination with the mental image of the figure just as if you are experiencing the G-loads of flying the figure. With practice, the technique becomes automatic, just as flying the aerobatic figure does.
The physical stress placed on the sport aerobatic pilot during G-loads calls for voluntary activation of the abdominal muscles to maintain blood pressure to the head and for involuntary muscle contraction of the shoulder, chest, and back muscles to stabilize the torso. These intermittent isometric contractions during an aerobatic sequence produce localized muscle fatigue that, when combined with repeated flights, places stress on the total endurance of the pilots physiological system.
No matter how well the airplane flies or how much talent the pilot possesses, a peak performance depends on the human system-physical and mental-being at peak efficiency. Like any sport, this demands both aerobic and anaerobic physical conditioning programs designed specifically for aerobatics.