Abdominal Training
Rapid movements can jolt the small facet joints at the back of spine over and over again. Exercises which use the middle part of joint's movement are safer than those which take the joint over to the end point of its movement. Movement of the pelvis directly affects the lumbar spine. In the neutral position the spine is correctly aligned and the spinal tissues are held at the right length. The deep trunk muscles make the spine more stable, holding the spinal bones together. It is the muscles on the surface which cause movement and if the hip flexor muscle is worked too hard it will pull on the lower spine, dangerously increasing the pressure within the disc. A muscle can only pull - it cannot push.
The three types of muscle action are concentric (lifting), isometric (holding) and eccentric (lowering). When deciding on an exercise, consider its type (which muscles are working), the duration (how long it lasts), frequency (how often performed) and intensity (how hard the exercise is). For an exercise to be truly 'specific' it must closely match the action which is to be improved. The trunk muscles must be able to effectively hold the spine in a stable position before any vigorous trunk exercise is attempted. Ideally, a programme begins by improving spinal stability and moves on to improve general movements.
All the fitness components must be balanced for optimal health. The quality (control) of an exercise is always more important than the quantity (number of repetitions) that can be performed. The spine is in its neutral position when the pelvis is level and the lower back is slightly hollow. Use the neutral position as often as possible to safeguard your back. Over time, as an exercise becomes easier then it must be made harder if any progress is to be made and so maintain the training effect.
Posture will affect the way you exercise, and the exercises you choose will in turn alter your posture. In an optimal posture the body segments are correctly aligned, so very little effort is needed to maintain the position. In the hollow back posture, the lumbar curve is excessive and the abdominal muscles are lengthened. In the round back posture the chin pokes forward, and the shoulders are rounded. The chest muscles are tight and the muscles controlling the shoulder blades are weak. In the swayback posture the hip and pelvis are thrust forwards and the body slouches. In the flatback posture, the normal lumbar curve is lost, and the lower back appears stiff.
The amount of body fat you have is more important than your weight. The most effective way to trim yourself down, and keep that way, is to combine a high quality, balanced diet with regular exercise. When the amount of energy coming into your body as food equals the amount going out through activity and exercise, you are said to be in 'energy balance'. Regular exercise is essential for effective, long-term weight loss. Our bodies combine tendencies towards being fat, lean and muscled. The combination of these factors you were born with determines your body type.
Training Style
Bending your the legs in a sit-up reduces the unwanted forces on the lower back. Do not allow the legs to move into a horizontal position when performing a leg raise action. The trunk crunch is an advanced exercise to be used only after initial abdominal strength has been gained using other exercises. The crunch focuses on the upper abdominal region and must be balanced by movements which emphasise the lower abdominal area, such as the pelvic raise. The knee raise can place stress on the lower back if it is performed with a 'swinging' action. Keep the action under control at all times, especially when lowering the legs.
Leverage is greatest when a lever is in a horizontal position. If an exercise doesn't allow you to keep your spine vertical, place your hand on something for support. Looking at the pelvis gives an important indication of lumbar spine position. Keep movements slow and controlled and use the middle of a joint's total movement more often than the ends. Try to keep your spine in the neutral position as often as possible and avoid nodding your head when performing any abdominal exercises. Wear comfortable clothing, and warm up gradually before beginning an abdominal training programme.
In water, buoyancy is related to body density. Thinner and muscular individuals tend to sink, while those with high body fat will float. Buoyancy can be used to assist or resist a movement, and to support a body part during exercise. Less streamlined objects offer greater water resistance, and can be used to make an exercise harder.
Summary
The spine is divided into regions: cervical (neck), thoracic (rib cage), lumbar (lower back), sacrum and coccyx (tailbone). The spine forms an 'S' curve, making it naturally springy. Bending and straightening the spine stretches and relaxes the spinal ligaments. Nerves transmit electrical messages for movement and feeling and if a nerve is trapped, movement and feeling can alter, giving weakness, pain or tingling.
The disc contains gel and acts as a shock absorber. Safe movement keeps the discs healthy but poor movements allow stress to build up in the discs over many years. Mid-range is the centre part of the total extent of movement possible at a joint. In its neutral position, the spine is correctly aligned and the spinal tissues are only at their normal length.
The split in the abdominal muscles that occurs during pregnancy is called a 'diastasis'. This may be larger if you have a narrow pelvis, or if you have a large baby or twins. The diastasis may be larger if you are overweight or have poor abdominal tone. The abdominal hollowing exercise can help regain your figure, but vigorous abdominal training is dangerous after pregnancy. Correct posture is important after pregnancy to help prevent back pain.
In an optimal posture - the hip, shoulder and ear lie in a vertical line. The pelvis is level and the lower spine should be gently hollowed. The inner edge of the shoulder blades are 4-5 in (10-12cm).
Body fat is much more critical than actual body weight. Your weight will include muscle, bone, tissues and fluids as well as fat. The feeding control mechanism (FCM) in the brain attempts to match the amount of energy you take in as food to the amount you burn off through physical activity. Starches and sugars are the energy-providing foods (carbohydrate). Fat is an energy store and is therefore high in calories.
Physical exercise increases your body's tick-over, the basal metabolic rate (BMR), reactivates your feeding control mechanism and increases muscle tone. You cannot substantially change the body type you were born with, but correct training can significantly adapt it.