Other than being used as an apparatus to rest a barbell on for squats, the power rack is generally overlooked in most gyms. The fact is, the power rack enables you to perform many training methods that can help you blast through training plateaus, whether your primary goal is to add muscle or get stronger.
A power rack, also known as a squat cage, consists of four vertical posts linked together to increase stability. A common size is 48 inches long by 48 inches wide and 84 inches tall, giving the trainee enough room to perform squats without hitting the posts. The posts have holes in which to insert safety rods. These rods can be positioned to catch a missed lift, thus increasing training safety.
The safety rods can also be positioned to perform partial movements through specific ranges of motion. Let’s say your sticking point in the bench press is halfway up. You can set the safety rods a few inches below the sticking point, place the barbell on the safety rods, and then perform your sets throughout this specific range of motion. By combining these “sticking-point reps” with full-range bench presses, you’ll have specialized training to help you blast through your particular training plateaus.
Another way power rack training can help you use more weight in full-range exercises is by performing partial-range-movements.
One early bodybuilder who popularized partial-range training was the late Chuck Sipes. Sipes won the 1960 IFBB Mr. Universe, later placing second to Sergio “The Myth” Oliva in the 1967 Mr. Olympia. Sipes sported 19½-inch arms at just 5'9½" and was as strong as he looked, reportedly being able to bench press 570 pounds raw and perform barbell curls with 250 pounds.
Sipes believed that heavy partial movements built tendon strength, but in fact what they do is disinhibit the nervous system so you can lift more weight. More specifically, heavy supports help raise the shutdown threshold of the Golgi tendon organ (GTO), which is a tension/stretch receptor located in the junction between a tendon and a muscle. When the GTO senses excessive tension, it shuts down the muscle. An example of such a shutdown occurs during an arm wrestling match, in which the weaker opponent appears to suddenly give up when their arm is slammed to the table after several seconds of maximal effort.
A practical application of this effect is to perform heavy isometric supports between conventional sets. With a heavy support, you simply unrack the weight and hold it just short of lockout (about 1/16 of full range). To perform this safely, you must set the safety rods in the power rack two to three inches below your lockout position.
Let’s say you can bench press 235 for a max single. After warm-up, you could perform three sets of five reps, which for most trainees translates into about 200 pounds. Between sets, perform eight seconds of heavy supports, progressively increasing the weight with each set. For example, for the first heavy support use 280 pounds (120% of one-rep max); second, 295 pounds (125%); and third, 305 pounds (130%). It’s another great solution for training plateaus. - FLEX