The principle of muscle confusion is used in many popular workouts like P90X, Insanity and Crossfit, and refers to the fact that the human body is built to adapt to different stimuli. The movements you perform most often are performed at the highest efficiency because the body adjusts to those movements. Because of this, the principle of muscle confusion in workouts hinges upon varying the exercises that are performed from workout to workout, so as to prevent a plateau.
Dr. William Kraemer, a professor of kinesiology with the University of Connecticut, demonstrated the principle of muscle confusion years before workout programs like Insanity, CrossFit and P90X became popular. Kraemer prefers to call the concept "variation." When you do pushups every day, your body will become more efficient at doing those pushups because your muscles will respond to the demands being placed on them. In order to avoid plateauing, or becoming stagnant in your exercise progress, it is important to vary the types of stimulation and signals to which your muscle groups are exposed.
The Bigger Picture
Scott Silviera, an exercise specialist at the California Health and Longevity Institute, says that muscle confusion can be divided into two principles: micro and macro. In a macro sense, everyone should mix up their workout routines every four to six weeks, if not more frequently, because of the psychological and physical benefits of doing so. This prevents boredom and staleness, and it allows you to target different muscle groups more frequently. This change could mean switching from a kickboxing class to yoga, or it could simply mean incorporating a few different exercises into your normal routine.
The Individualized Principle
The micro principle of muscle confusion, according to both Silviera and Kraemer, is that each person has individualized needs. For 80 percent of the population, small changes in day to day workout routines are important. This means frequently adding new exercises that target the same muscle groups. If Day 1 of a workout involves bench presses, the next workout should include chest fly exercises. These two exercises work the same muscle groups, but they add variation and, ultimately, confusion to the muscles. Muscle memory and the risk of plateau are no longer issues when an individual's daily workout routines are slightly varied. Mixing up your routine after four to six weeks is essential, and Kraemer recommends changing things up more frequently. He suggests a two-week cycle of varied workouts for most people. This means that you perform the same four or five routines for two weeks. After two weeks, you start the same routine over again.
Rest days are necessary when using the principle of muscle confusion. Kraemer recommends incorporating a four-day-a-week program that allows for rest days. In this plan, Monday is a heavy day involving weight lifting for all major muscle groups, and Tuesday is a light recovery day involving light weights and muscle recovery. Wednesday is a rest day, and Thursday involves metabolic training with short rests, heavy sweating and light to moderate weight. Friday involves a light recovery workout, and Saturday and Sunday are rest days. Although this is only one option, it is important to note how much rest is involved in that plan. Some trainers even recommend 48 to 72 hours of rest to recover after a hard workout. Without rest, your body will not be able to perform adequately and injury is likely.
- Dr. William Kraemer, Professor of Kinesiology; University of Connecticut; Storrs-Mansfield, CT
- Scott Silveira, Exercise Specialist; California Health and Longevity Institute; Westlake Village, CA
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