The purpose of physical training is to cause serial adaptations to the organism (you/ a trainee) over a period of time, which add up to become certain physical qualities, the possession of which will improve the trainees' performance (in athletics, work, life in general). These adaptations affect all aspects of the organism (mental, neural, structural, metabolic, hormonal, circulatory, etc.)
A critical load of stressors must be applied through training to cause an adaptation(s) to the trainee (you or your client/athlete). The concept is simple; an organism encounters a new stressor in its environment; this stressor then induces a genetic mutation in the organism, which secures its future survival when faced with the stressor again.
The essence of effective training lies in controlling and optimizing these adaptations by correctly calculating, prescribing, and applying the dosage of stressors according to your/the trainee's purpose; this is where the concept of training load comes into play.
Aspects Of The Load
There are two interrelated aspects of the training Load: the external Load and the internal Load. We define external Load by calculating the relevant physical quantities according to the type of training done (i.e., Kilograms lifted, meters ran/swam/cycled, a number of throws, etc.); essentially, it describes the amount and intensity of work done.
External Load: KG Lifted, distance ran and at what speed, number of jumps and at what height, number of throws and what length, etc.
The internal Load refers to the effect this external Load has on the organism internally (i.e., its biological impact on all the subsystems of the organism.) Another less training-specific word for internal Load is simply "stress."
Image 1: The body's reaction to a stressor(s) that eventually becomes an adaptation.
Internal Load: The biological effect a particular external load has on all the subsystems of a trainee.
The internal load/stress developed in training must be above a critical level for the adaptive process(es) to engage. If the internal Load is great enough, it becomes the catalyst of adaptation, known as stimuli overload.
Overload: A training load exceeding the normal/habitual magnitude the training has currently adapted to.
Simply put, a training adaptation would take place only if the external Load prescribed is above the habitual level, so that the internal Load developed in reaction to it is greater than what the organism has already adapted to. If a standard exercise with the same weight and number of sets and reps is used repeatedly for a period of time, no additional adaptations after the initial phase (in which the external Load was enough to cause overload) will occur; physical fitness will not improve. After a more extended period, slow decay of the ability will occur.
For this reason, it is necessary to increase either the average intensity (% maximum for a given exercise) or the total amount (sets and reps, distance, time) in training over a period of time.
The methods of manipulating the external Load in training over extended periods can be very complex. The same external Load can produce very different internal Loads in different trainees according to age, genetic factors, training history, their current level of previous adaptations, and other factors; so, the way a trainer increases the external Load over time will vary from person to person. The more advanced a trainee is, the longer a training cycle that constitutes an overload stimulus will be. For a beginner, a single training session constitutes an overload; for advanced trainees, it can take more than a month's worth of sessions; this is just one example of how much the amount of external Load needed to cause overload can vary between different trainees.
Foundationally, we define the training Load as a qualitative and quantitative combination of the intensity and amount of a training unit. At StratFit, we have fully developed the Load concept and created an entirely new system of science around it. Check out our applied science white papers to dive much deeper into our ideas.
The Bottom Line
The art of training comes down to calculating and prescribing the external loads across time that will develop the optimal level and kind of internal loading at the right times, which finally causes the desired adaptation(s) to manifest when it/they are wanted. This art is the essence of athletic preparation and applies to all competitive and non-competitive trainees.