Starting Strength, 3rd Edition - Mark Rippetoe [43]
A leg press machine – the “Hip Sled” – is even less useful to a lifter who is already strong enough to squat. By restricting the movement of joints that normally adjust their position during a squat, this device eliminates the expression of your normal biomechanics. The leg press may be useful for geriatric trainees or for special populations that cannot effectively use the squat as an exercise. But it is particularly heinous for healthy younger people because it allows the use of huge weights and therefore facilitates unwarranted bragging by those who should be squatting. A 1000-pound leg press is as irrelevant as a 500-pound quarter-squat.
Personal Equipment
Supportive apparel, such as squat suits, squat briefs, power socks, bench press shirts, and other such items, is designed to help powerlifters lift more weight at a meet where such equipment is permitted. Powerlifting is an extremely technical sport due to the use of this equipment, but it has no place in a program of strength training for athletics and fitness. Remember: lifting more weight is not always the same thing as getting stronger. This should be obvious in light of the principles already discussed regarding squatting and strength.
Belts and wraps
Less obvious is the role of belts and knee wraps. A properly designed and adjusted belt is useful as a safety device when you’re squatting heavy weights. A belt protects the spine by increasing the amount of pressure that can be applied to it by the muscles that support it. The belt itself reinforces the “cylinder” of the ab muscles around the spine. At the same time, the belt acts as a proprioceptive cue for a harder abdominal muscle contraction: you can actually squeeze harder with a belt on than you can without one, just as you can push harder against a loaded barbell than you can against a broomstick. This effect ultimately produces both stronger abs, due to the stronger isometric contraction facilitated by the belt, and a stronger squat, due to the heavier loads made possible by the more stable spine.
Figure 2-59. Increased pressure against the spine is necessary for the safety and efficiency of the lift. The belt facilitates this increase by providing a platform for proprioceptive feedback for increased abdominal muscle contraction. Pushing against the resistance of the belt makes for a harder abdominal contraction. And the volumetric containment it provides allows an increase in pressure in the abdominal and thoracic cavities.
A suit is different in that it actually enables you to lift weights that are heavier than those you can lift without the suit. With a suit, some of the kinetic energy of the descending, bar-loaded, eccentric contraction is stored as elastic energy in the suit material and in the compressed skin and muscle under the suit. That energy is then made available to the lifter as he rebounds up, so the suit is in fact an artificial aid. It has been argued that the belt is too, but a belt does not function across a joint going into a sequence of flexion, stretch reflex, and extension, like a suit does. Spinal support and safety are necessary for our general strength training purposes, while a squat 30% heavier than that which can be done unaided is not. Leave the squat suit for later, when you’re entered in the meet.
A properly designed belt is the same width, usually 4 inches, all the way around. Many millions of cheap, junky belts have been produced with 2-inch buckles and fronts, and either 4- or 6-inch backs. These belts were designed by someone who did not understand how a belt works. For the belt to function correctly, it must act around the complete circle, and there is no reason for it to be wider in the back than