6. Principles of Weight Training

The previous chapter discussed the variables that should be considered when designing a training program. This chapter will discuss how to design a training plan by modifying the training variables over time. Based on the muscle physiology and the adaptations that take place after training, some principles have been derived in order to simplify the procedure of designing a training plan. These principles (ACSM 2009, Kraemer and Ratamess 2004, Johnston 2013) are:

• Progressive overload: There must be a stimulus (workout) and this must be gradually increasing over time to further improve performance.
• Specificity: The training adaptations are specific to the stimulus applied.
• Variation (Periodization): The training stimulus should change (within the specificity limits) to remain challenging and effective.
• Individuality: The magnitude of the adaptation to the training stimulus (i.e., performance improvement) is different for each person.

Other principles are:

• Reversibility: The positive effects and health benefits of training are reversible. When individuals discontinue their exercise programs (detraining) performance decreases.
• Interference (concurrent training effect): When training several components at once (e.g., strength and endurance) the stimuli may interfere with each other, thereby slowing adaptation in one or all components.
• Initial values and diminishing returns: Individuals with low initial performance levels will show faster improvement and greater relative gains. As individuals approach their genetic ceilings the rate of improvement slows down.

The last three principles are indirectly included in the progressive overload, specificity, and individuality principles respectively and will be discussed there.