Over the past few years some of the “box” style fitness systems have become fairly prominent. Each has its own unique style and most are valuable for what they achieve. Unfortunately, most also only address one phase of training and never actually properly prepare the body or transition the body. Injury and plateaus are too often the result of a poorly planned or executed workout program. To keep this posting fairly short I am only going to address strength training.
The first thing to remember is that the body will always try to stay at a certain set point (homeostasis), but the body will adapt to the demands imposed upon it. This is a very simple concept until we think about the different tissues in the body. Not all tissue adapts at the same rate. Muscle adapts faster than connective tissue (due mostly to the lack of nerves and vascularity in tendons, ligaments, etc). Muscles work in one of three ways; isometric contractions stabilize, concentric contractions shorten the muscle while under tension and usually accelerating, and eccentric contractions lengthen the muscle while under tension, usually decelerating. Although injury can occur with any of these movements, many injuries happen while the muscle is lengthening (eccentric contraction) while under tension. The down phase of a squat is a good example – the quads are lengthening while trying to control deceleration and therefore still contracting. Injury can occur very easily if the muscle gets too much stronger than the connective tissue and force or velocity is attempted. If the muscles are stronger than the connective tissue, or the neuromuscular system doesn’t efficiently respond, the connective tissue will tear.
Another aspect of some of the “box” workout programs is that they repeatedly stress the same musculature in the same fashion. For example if one were to perform push ups day after day, results would be obtained in the first few weeks but then push ups would become easy and continued adaptations would cease. As the body becomes accustomed to an activity, the body becomes more efficient and fewer muscle motor units are required – progress stops. To continue to see improvement, the body must have new demands imposed upon it that require increased motor unit recruitment. Increased motor unit recruitment increases the number of muscle fibers that are activated allowing for greater potential growth.
Because tissue adapts when appropriate stimulus is imposed, manipulating exercise variables becomes paramount to achieving greater results. Volume (sets and reps), intensity, velocity, training frequency, planes of motion and exercise selection, as well as coordinated movement patterns all need to be changed every four to six weeks. This type of periodized training leads to greater improvements than non-periodized training as specific combinations illicit specific adaptations.
A safe program that addresses dynamic stabilization, muscular endurance, muscle growth and strength, and then power and velocity in a progressive manner will lead to the greatest adaptations. Stabilization training builds joint support during movement allowing for the practitioner to dynamically accelerate and decelerate in a controlled fashion. Muscular endurance training builds type I muscle fibers that are used for core and joint stabilization – a precursor to building strength and power. Hypertrophy and strength training (type II muscle fibers) will make the muscles bigger and stronger as well as activate the neuromuscular system to adequately overcome and control external and internal forces. Since power is the product of force x velocity it requires increased motor unit recruitment from strength training and neuromuscular efficiency from stabilization training (to adequately produce velocity one must be able to push off of something – usually the ground, see Newton’s Laws of Physics). By utilizing a periodized exercise plan, the body will properly be prepared for each phase of training and progressions can be made in a safe manner that minimizes the potential for injury.
Info taken from:
Clark, M., & Lucett, S. (2010) NASM’s essentials of sports performance training. pp. 257-267; Baltimore Lippincott, Williams, and Wilkins.
