Progression Models in Resistance Training for Healthy Adults

Nicholas A. Ratamess, Ph.D.; Brent A. Alvar, Ph.D.; Tammy K. Evetoch, Ph.D., FACSM; Terry J. Housh, Ph.D., FACSM (Chair); W. Ben Kibler, M.D., FACSM; William J. Kraemer, Ph.D., FACSM; N. Travis Triplett, Ph.D.


March 01, 2010

In This Article

Progression Principles

The foremost principles of RT progression are progressive overload, specificity, and variation.[157] Countless RT models can be effective if these principles are incorporated and manipulated into the design. The magnitude of improvement depends upon the individual's training status and genetic predisposition.[8] Progressive overload is the gradual increase of stress placed upon the body during exercise training. Among untrained or novice populations, physiological adaptations to an RT program may occur in a short period. Systematically increasing the demands placed upon the body is necessary for further improvement and may be accomplished through altering one or more of the following variables: 1) exercise intensity (i.e., absolute or relative resistance/load for a given exercise/movement) may be increased; 2) total repetitions performed at the current intensity may be increased; 3) repetition speed/tempo with submaximal loads may be altered according to goals; 4) rest periods may be shortened for endurance improvements or lengthened for strength and power training; and 5) training volume (total work represented as the product of the total number of repetitions performed and the resistance) may be gradually increased (e.g., 2.5-5%[75]) (Table 2).

Specificity. All training adaptations are "specific" to the stimulus applied. The specific physiological adaptations to RT are determined by various factors, including 1) muscle actions involved,[56] 2) speed of movement,[39,44] 3) range of motion,[145] 4) muscle groups trained,[156] 5) energy systems involved,[259] and 6) intensity and volume of training.[225] Although there is some carryover of training effects to other general fitness and performance attributes, the most effective RT programs are those that are designed to target-specific training goals.

Variation. Variation, or periodization, entails the systematic process of altering one or more program variable(s) over time to allow for the training stimulus to remain challenging and effective. Because the human body adapts quickly to an RT program, at least some changes are needed in order for continual progression to occur. It has been shown that systematic variation of volume and intensity is most effective for long-term progression.[254] Variation may take place in many forms and manifests by manipulation of any one or a combination of the acute program variables. However, the two most commonly studied variables have been volume and intensity. The concept of periodization was developed based on the studies of general adaptation syndrome by Hans Selye[239] to optimize performance and recovery.[74,100] In addition to sport-specific training, periodized RT has been shown to be effective for recreational[54] and rehabilitative[67] objectives and is supported through a meta-analytical investigation to be superior to nonperiodized RT.[223]

Classical Periodization. The classic (linear) model of periodization is characterized by high initial training volume and low intensity, and as training progresses, volume decreases and intensity gradually increases. This traditional model of periodization is carried out to enhance fundamental fitness variables through training in a designated succession to serve as an appropriate arrangement to elicit "peak" performance of a distinct fitness variable (e.g., strength, rate of force development [RFD], and/or peak power) for a precise and often narrow time window.[74] Most, but not all,[14] studies have shown classic strength/power periodized training to be superior to nonperiodized RT for increasing maximal strength (e.g., 1 repetition maximum [RM] squat), cycling power, motor performance, and jumping ability.[252,254,272] It appears that longer training periods (>6 months) may be necessary to underscore the benefits of periodized training[273] because periodized and nonperiodized training are effective during short-term training. Important to periodization is the use of rest days to allow recovery and to reduce the probability or magnitude of overtraining.[79]

Reverse Periodization. A reverse linear periodization model has also been studied.[227] This model is the inverse of the classical model in which intensity is initially at its highest and volume at its lowest. Subsequently, over an extended time, intensity decreases and volume increases with each phase. This periodization model has been used for individuals targeting local muscular endurance (LME) enhancement[59] and was shown to be superior for enhancing LME to other periodization models when volume and intensity were equated.[227] Strength improvements following this model have been shown to be lower compared with linear and undulating models.[227]

Undulating Periodization. The undulating (nonlinear) model of periodization enables variation in intensity and volume within a cycle by rotating different protocols to train various components of neuromuscular performance (e.g., strength, power, LME). For example, in loading schemes for core exercises (those exercises most specific to target goals), the use of heavy, moderate, and light resistances may be systematically or randomly rotated over a training sequence, for example, 3-5 repetition maximum (RM) loads, 8-10 RM loads, and 12-15 RM loads may used in the rotation. This model has compared favorably with linear periodized and nonperiodized multiple-set models[14] and has been shown to produce superior strength increases over 12 wk of RT compared with the classical model.[226] Further, this model has demonstrated advantages in comparison to nonperiodized, low-volume training in women.[155,169] Few investigations have evaluated the impact of undulating RT for multiple fitness objectives.[199] Most recently, this model has been demonstrated superior over nonundulating RT for generating fitness and performance enhancement outcomes among firefighter trainees.[209]