Training Principles


Adaptation to exercise are specific to training stimuli. See Training Specificity.

Progressive Overload

Greater demand (intensity or duration) continually placed on the body in incremental stages. Corresponds to the first stage of SAID (Stress or Stimulus). If overload is not present, adaptation is not necessary, and will not occur. If overload is too great, acute overtraining may occur. If the same training load is used over a long period of time, performance improvements decrease due to accommodation (Zatsiorsky & Kraemer 1995).


Second stage of SAID (Adaptation or Response) occurs during this stage. Chronic overtraining can occur if recovery is insufficient over time. If recovery is too long, regularity is compromised.


Detraining will occur if specific overload is not practiced at regular intervals. See Residual Training Effect.

Diminishing Returns

The Principle of Diminishing Return explains how the magnitude of adaptation diminishes with greater training volumes or durations at any given time. One example is how additional sets of weight training yield progressively less benefit (see Strength Dose-Response Curve).

The Principle of Diminishing Return also applies to our ability to make as great of gains as we once did earlier in our exercise journey. For example, as a beginner, relatively small training loads are required to bring about large improvements. As one progresses, heavier workloads are required to make the smallest gains.


A basic prerequisite for continued adaptation is variation. Performance improvements will decrease if the same exercises and training loads are continued for a prolonged period of time (AKA Accommodation). Training variations inhibit accommodation and ultimately the exhaustion stage of SAID. Polarizing training stimulus around a target response between workouts can also help recovery between workouts. These variations indirectly assists recovery since the metabolic pathway are not taxed in the exact same way every workout. As a beginner, progress can be made most every workout. Variation is inherent due to relatively rapid progress in the initial phases of training (see Initial Level of Fitness). As progress slows, subtle variations must be made in other ways for progress to continue (see variation examples below).

Variation Examples

Cable Seated Chest Press


  • Resistance training
    • Performs additional repetition(s) most workouts
      • progressing from 8 to 12 reps
      • increases in muscular endurance
    • Resistance is increased
      • after 12 reps are achieved
      • increase in strength
    • Alternating cycle continues
    • Also see Systematic Progress Methods
  • Cardio training
    • Walking Programs
    • Progressively increase walking time throughout a few weeks
      • Increases in endurance
    • Increase walking speed at conclusion of few weeks
      • Increase in speed
    • Alternating cycle continues

Intermediate Trainees

Barbell Shrug


Advanced Trainees

Variation Deviations

Conceptual Fitness Continuum

  • Variations should be subtle
  • Training goals are specific to activities and may vary throughout body
    • Example
      • Athlete may require running endurance and throwing power
    • Training certain fitness components may inhibit the development of other fitness components

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