Weight Training: Three Phases of the Repetition
A repetition is one range of motion of the exercise you are doing. A group of reps that are divided by periods of recovery are described as a set. For example if you do ten sit-ups, rest, ten more sit-ups, followed by another rest period, you’ve done two sets of ten sit-ups.
There are many aspects that influence every repetition. The more knowledge you have concerning these factors during each rep will allow you to better understand how your muscle is growing. By applying this wisdom to every exercise you perform you will increase your efficiency and effectiveness.
A repetition consists of three phases. Phase one is concentric contraction or the lifting of the weight. This is where your muscle contracts or shortens. Phase two is transition when the muscle at its shortest length. Phase three is eccentric contraction when the weight is lowered. During eccentric contraction the muscle is lengthened as the joint is extended. A common misconception is that the muscle only contracts during concentric contraction and relaxes during eccentric contraction. The truth is that the muscle contracts or is being worked during both motions. That fact is what makes all phases of the repetition equally important.
During concentric contraction, the muscle being exercised shortens and pulls the bones above and below the joint closer together. Exercises with lighter weights allow only a small portion of the muscle to contract. A heavier weight or a fatigued muscle will require the muscle group to recruit more fibers to accomplish the rep. This leads to the axiom that lighter weights with a high number of reps increases muscle tone while heavier weights and lower reps per set develops muscle mass and strength.
Motion during your repetition should be controlled. Inhale slowly while contracting your muscle. Avoid swinging the weight or using momentum to complete the rep. A slow controlled movement allows for the maximum muscle recruitment. If the weight is swinging during your motion, a portion of the resistance workload is being lost to momentum. This reduces the effectiveness of your workout and may even lead to injury.
The transition phase is when the muscle is at its most contracted point. As your muscles adapt to its workout you will notice that weights that were once heavy become easier to lift during the concentric contraction phase. This is mainly due to increased muscle mass and strength but could also be due, in part, to the muscle learning to more efficiently recruit muscle fibers. To prevent the muscle from getting used to its exercise you will want to vary the way it is worked. That is way several exercises per muscle group is so important.
There are things you can do during the transition phase to add variety to your workout. During the transition phase when your muscle is at its shortest position you can pause for a second or two to get an intense contraction. This technique is called peak contraction. This method also requires your muscle to recruit fibers that are not usually used during a normal repetition.
Another variation you can perform during the transition phase is lowering the weight an inch or two as if entering the elongating eccentric contraction phase but instead of going to full elongation return the muscle to its fully contracted position once more before lowering the weight completely. This motion is referred to as pulsing. For an even more intense contraction try pulsing two or three times during the transition phase.
Many weight trainers mistakenly neglect the last phase, the eccentric contraction. They let the weight simply drop with minimal muscle input. It is true that during this elongation of the muscle not as many fibers are being utilized. However, those that are being recruited to control the weight are working under more stress. Simply put, you are lowering the same weight but with less muscle fibers. This means that each fiber involved has to endure greater force than it did during the concentric contraction. The key to effective eccentric contraction is deliberate control of the weight while remembering to exhale slowly.
These three factors taken as a whole produces an exercise’s full range of motion. Movements that start or stop too early reduce the number of muscle fibers being recruited. Do not discount the importance of maintaining tension in your muscle during eccentric contraction. It’s just as important as the initial concentric contraction when it comes to building muscle and increasing strength. Remember to breathe naturally and keep your movements controlled. If every set you perform consists of reps with good form, you will see increased productivity and efficiency in your training sessions.
