Here’s what you need to know… How you perform your reps plays a huge part in stimulating the gains you want. The principle behind CAT is that when you’re lifting a submaximal weight, you can compensate that lack of resistance by accelerating more quickly. Dynamic correspondence reps require that you should lower and lift the weight the same way you do a max lift – same speed, same acceleration, and same tension. Constant tension reps are based on the principle of occlusion, which is when blood entry to the muscle is limited, depriving it of oxygen. Normal reps allow you to have energy to do more reps at a given weight while still using enough force to stimulate growth and strength gains. How Should I Do My Reps? I never get asked that question. That’s a shame because how you do your reps plays a huge part in stimulating the gains you want. Think about it. The workout itself is nothing but a long group of repetitions spread over different exercises. The basic unit of your session is the rep. The more reps you get right, the better your gains will be. By “get right” I mean doing the rep the proper way in order to get the exact stimulation necessary to achieve the gains you desire. There’s more than one proper way to do reps, and the style you use depends on what your goals are. The 4 Rep Styles 1 – The CAT Rep The concept of compensatory acceleration training (CAT) was popularized by powerlifting legend Fred Hatfield. The basic premise is simple: Force is equal to mass times acceleration (F = ma). In other words, you can increase the amount of force the muscles have to produce by increasing the mass (weight on the bar) and/or the acceleration you impart on the barbell when you lift it. So the principle behind CAT is that when you’re lifting a submaximal weight, you can compensate for that lack of resistance by accelerating more quickly. What does such a rep look like? Let’s say you’re doing a bench press. It means trying to blast the barbell off your chest and trying to accelerate it as much as possible for as long as possible. Another aspect of CAT is the transition between the eccentric (lowering) and concentric (lifting) portions. The transition itself should be rapid. This requires very strong antagonist muscles to stabilize the joints at the point of reversal. For example, you need strong rhomboids, rear delts, and lats to do a fast turnaround on the bench. Even the biceps can help. The majority of the eccentric phase should be done under control (not slowly, but you must control the barbell), but the transition point is rapid and then you attempt to produce as much acceleration as possible on the way up. If the weight is heavy, the bar might not actually move fast. The acceleration is meant to compensate for the lower weight, and a heavy weight means you won’t be able to compensate much and the acceleration won’t be high. Regardless, you still attempt to produce as much acceleration/speed as possible. Pros of CAT This rep style maximizes peak force production at any given load, so it makes the muscles stronger. By working on acceleration you’ll also develop more power/explosiveness than if you used a more “regular” lifting style, which is good if you’re an athlete trying to be explosive. By attempting to move as fast as possible you maximize fast-twitch motor unit recruitment. Over time you’ll become more efficient at recruiting those fibers, which will obviously help you gain more strength, size, and power in the future. By using the stretch reflex at the turnaround point, you become more efficient at using it in muscle actions, which can help you in athletic activities that require the use of the stretch reflex. Cons of CAT It will sound weird because I mentioned that CAT maximizes peak force output during a rep at a given weight, but CAT actually isn’t optimal for building “1RM slow-speed strength.” You’ll become very strong on fast reps, but as soon as the weight is too heavy for you to accelerate, you won’t be able to push it farther. Someone who trained otherwise, however, will normally be able to grind out a weight much heavier than the one he can lift with acceleration. I also mentioned that CAT leads to a higher peak force production for a given weight. That’s true. But it doesn’t mean that the average force production of the whole range of motion is higher. In fact it isn’t. What happens is that you produce a very high peak of force initially, but the later portions of the range of motion have a fairly low force production level because you’re relying on the momentum built from the initial thrust. In reality, the momentum actually “lowers the mass to overcome” in later parts of the movement, which diminishes the amount of force to produce. What happens is that you become very good at producing a burst of force over a very short time frame/range of motion, but you lose the capacity to keep that force production “turned on” for the duration of the rep. That means you won’t be
Origin: The Rep Bible