The foundation of any strength training program is the repetition. Surprisingly, in most strength training circles, little if no attention is paid to “how” a repetition is performed. It is commonplace for an exercise professional to attend a conference and listen to strength coaches, exercise physiology researchers, and pundits lecture and share slides that detail what exercises should be performed, how many sets, how many reps, how many days per week, how much weight, machines or free-weights (or body-weight or bands); yet almost no one discusses the foundation: The repetition. The mindset for productive strength training is this: Perform one perfect rep at a time. What is a perfect rep? To answer this, we must first understand the basics. Intensity is the stimulus for the cascade of positive responses we seek from strength training and the primary and immediate goal of strength training is to fatigue a targeted muscle by exposing it to tension over a period of time. Therefore, the guidelines of repetition performance must contribute to the outcome of creating muscular tension and in doing so, making an exercise more intense.
Obsess over each checkpoint during your next workout (this is going to get scientific!):
✓ Raise the resistance in a controlled manner, thus minimizing momentum. Performing a controlled concentric contraction keeps constant tension on a muscle which leads to fatigue and the recruitment of more glycolytic, fast twitch muscle fibers. According to the force-velocity relationship for muscle, if the velocity of shortening is slow, the tension that can be developed is large, and if the shortening velocity is fast, the tension developed is small. Because the goal of strength training is to place tension on a muscle and eventually fatigue it, we must lift the resistance slowly. When a weight is raised quickly, momentum is incorporated thus taking tension off of the targeted muscle. In such instances, the resistance may actually be moving by itself. In order to efficiently recruit and fatigue muscle fibers, tension must be continuous. This guideline is particularly important at the beginning of the set when the targeted musculature is fresh and repetitions are more easily performed. Because fatigue has not set in, we are capable of moving the weight fast or “throwing” it. Throwing the weight minimizes efficiency of the set (as described above) and is dangerous due to excessive force experienced during the acceleration phase. As the set nears momentary muscular failure, we can attempt to lift the weight as fast as possible, however, because the exercising muscles are fatigued, we will likely be unable to lift the weight fast. Although we may attempt to lift the weight fast, the actual outward display of movement of the resistance is quite slow. Note: It is the intent to move the weight fast or “explosively” that develops “explosiveness,” not the actual outward display of fast movement.
✓ Pause momentarily in the contracted position. A pause in the contracted position demonstrates control of the repetition and keeps tension on the targeted muscle. A distinct pause in the contracted position ensures that momentum did not play a significant role in raising the resistance. This guideline does not apply to closed chain movements such as the chest press or leg press. In these instances, a pause would serve as a rest or a period in which the muscle is unloaded.
✓ Change directions in a slow, smooth manner without incorporating momentum. Specific attention must be paid to changes of direction, from concentric to eccentric and eccentric to concentric; it is during these changes that momentum is commonly incorporated, thus minimizing muscle tension and muscle fiber recruitment. The rapid unloading and loading of the joints and musculature is not only inefficient as a means of fiber recruitment but may also lead to injury as a result of increased force.
✓ Lower the resistance in a slow and controlled fashion. The same muscles used to raise a weight are also used to lower a weight. In order to keep tension on these muscles, this phase of the repetition must not be performed rapidly allowing the weight to drop or fall. Because eccentric or negative strength is estimated at 40% greater than concentric or positive strength, the negative portion of a repetition should be approximately twice as slow as the positive phase. Research indicates that eccentric contractions produce greater tension than concentric or isometric contractions. For this reason, special attention should be paid to lower the resistance in a slow manner.
✓ Move through the greatest possible range of motion that safety allows. Moving through a full range of motion ensures that the entire muscle is worked. Generally, the greater the range of motion, the greater potential for strength gain and protection from injury. Full range of motion strength training may also improve a joint’s functional range of motion. Of course, if you have discomfort in a particular portion of the range of motion, modify the range of motion.
✓ Avoid creating leverage by altering body position. The human body will instinctively take the path of least resistance. Accordingly, trainees will do anything possible to make a repetition easier, often times while completely unaware they are doing so. This often includes shifting or changing body position in order to produce an improvement in leverage. Examples of this include arching the back on the bench press or raising the buttocks off of the seat of a leg press.