Periodization, the systematic planning of exercise and athletic training. It is one of the cornerstones of high level sports and physical performance and without it, training has no context and no direction.

This series will cover the big picture as well as dive into the small nuances of what makes periodization such an important topic to learn for any aspiring strength & conditioning coach or high performance trainer.

This first part will talk about the history of periodization and how the concept came to practice, as well as the true definition of periodization and the physiological basis behind physical training and planning.

~1900 words ; 10-15 minute read

Read Part 101: Introduction
Read Part 201: Training Variation
Read Part 202: Training Effect & Phases
Read Part 301: Review of Periodization Models
Read Part 401: The Complexities and Problems of Periodization Theory

Introduction To Periodization

Many articles posted online about training periodization revolve around how to set up your training to "bust through plateaus" and hit your "biggest PRs ever". While periodization certainly does help you in doing both, many authors neglect to write about the "whys" and are inconsistent when using training terminologies. What's the difference between linear and daily undulating (DUP)? What's block training? I thought blocks were called phases? How do I linearly progress man? A lot of terms get thrown around without proper context, and unless you have some background in exercise science or an in-depth understanding of exercise physiology, it can get confusing. To play devil's advocate though, there are many concepts and training methods that share different names; usually due to that fact that different researchers and difference coaches around the world use them and have made them popular in their own training niche or sport.

Quick example: tempo training in the world of running (tempo running) consists of a more fast-paced run usually right at an athlete's lactate-threshold. However in cycling, tempo training is done below anywhere from 10-15 beats below an athlete's lactate-threshold. What seems like a small adjustment can be the difference between increased endurance, or poor recovery and overtraining. This may be a specific example, but I hope you get the idea.

Before we even get into the types of periodization and how to manipulate training variables, we must know WHY things are set up the way they are. Training terminology must be consistent and training modalities need to be contextualized.

With all that said, let's jump into it.

The History Of Periodization

How did the concept of periodization come to fruition and why was it invented?

Sport training theories and methodologies have been developed throughout human history, dating back to the 2nd century AD, notably by Roman philosopher and physician Galen and ancient Greek scientist Philostratus. In order to achieve spectacular results and performances at the ancient Olympic games, these 2 gentlemen developed their own training theories which have laid down the foundation for contemporary training periodization.

Galen created the idea of building strength without speed, developing speed without strength, then using intense exercises to combine the 2 to create the most powerful athlete possible. Philostartus on the other hand, constructed the idea compartmentalizing training protocols:

"compulsory 10-month period of purposeful training followed by 1 month of centralized preparation... prior to the Olympic Games".

Sounds an awful lot like the off-season and in-season training camps of today, right?

Let's fast forward a few thousand years.

In the 20th century, the contributions from a factory supervisor named Frederick Winslow Taylor further paved the way for modern training management. As the founder of the "Principles of Scientific Management", Frederick believed there was a systematic way to organize and plan in order to achieve the best outcomes in the most efficient manner. The appeal for the scientific method came from several different driving forces: the fact that the explanatory power of the scientific method resonated with the society, and the ingrained human attraction for simplicity, rules and automatized solutions. What originally was a paradigm developed for the engineering and automobile industry, has given way to exercise and sports performance planning.

How do we achieve the best performance possible on any given date? How do we create a training system that works for a particular group of athletes? How do we improve performance given our current resources and limitations?

These are the questions periodization attempts to answer for a variety of different sports, athletes and scenarios.

Popularization of Periodization

"All World Records Shall Be Ours!" A Soviet poster from 1948.

The concept of training periodization was not developed on a large scale until the 1950's, where former USSR teachers, coaches and scientists called for separate training periods, general and specialized phases. These phases, encompassing the training of basic athletic abilities, cardiovascular fitness and strength, were applied in a sport performance as well as physical education setting. When numerous studies on exercise physiology and human biology were published to back these concepts, sport scientist Lev P. Matveyev compiled the massive amount of data. Matveyev is to this day, recognized as the founder of the traditional theory of periodization (commonly and wrongfully called linear periodization - more on this later).

The definition of periodization

Although there have been several models of periodization developed since Matveyev's traditional model, it is widely agreed upon that the definition of periodization is the divison of training periods and the principle of cyclical training where programming variables such as intensity, volume, frequency, rest, and exercise selection among others, are strategically manipulated and varied in order to reduce the risk of injury and maximize sport performance for individual athletes or sports teams.

Periodization takes into consideration the level, training age and genetic predispositions of an athlete in order to avoid overtraining and allow them to peak for one or several competitions. In a periodized training plan, certain time-frames exists for the manipulation of programming variables, these time frames are termed macrocycle, mesocycle and microcycle.

A macrocycle is considered the longest duration of the training cycle, usually several months in length or even a few years. For example, a quadrennial macrocycle describes a 4-year long program used to prepare an athlete or sport team for the Olympic games. A macrocycle is comprised of several mesocycles, which are a few months in length and can be defined as a prepatory, competition or transitional phase. Lastly, mesocycles are further divided into microcycles which deals with training on the weekly-basis.

Macrocycle (months to years)

Mesocycles (weeks to months)

Microcycles (training on the week to week basis)

Using this definition, many popular strength programs that you and I are familiar with (Stronglifts 5x5, Texas Method, Starting Strength, etc), ARE periodized. Periodization does not imply some fancy, advanced, over-the-top program meant for elite athletes... although it can be. Periodization simply means your training plan is divided and organized in a way that makes sense and is in line with the nature of human biology and exercise physiology. The difference between a periodized program for a beginner vs. an elite athlete lies in the number of variables that are controlled for and manipulated. A weight training enthusiast can see results with the simple manipulation of intensity and volume, whereas elite athletes will need more advanced manipulation of loading schemes, exercise selection and nutritional intake in order for them to achieve those incremental gains in performance.

Periodization can be as simple, or as complex as you need it to be. That's the beauty of it.

Physiological Basis Behind Periodization

What is periodization based on? How do we determine what variables to manipulate and how to manipulate them to our advantage in terms of training adaptations?

The answer comes from the understanding human physiology and how we respond to stress. Here are 3 of the overarching principles and paradigms that make exercise and sports planning possible: General adaptation syndrome (GAS), Stimulus-Fatigue-Recovery-Adaptation (SFRA) and Fitness-Fatigue Model (F-F)

General Adaptation Syndrome (GAS)

The General Adaptation Syndrome (GAS) is a model of stress created by Hans Selye to describe and stereotype the physiological responses of the nervous and endocrine system to a stressor. GAS is categorized into 3 stages: alarm stage, resistance stage and the exhaustion stage. During the alarm stage, the body reacts to the stressor by releasing hormones in order to restore homeostasis. The resistance stage, which can also be referred to the adaptation stage, is where physiological defenses are strengthened in anticipation to future stressors. The exhauastion stage is reached when the stressor still persists and the body does not have sufficient resources to defend or repair itself.

The GAS syndrome as shown by a mouse reaction to a cat.

In relation to exercise and sports training, a disruption in homeostasis (in the form of training stress) manifests itself in the form of muscle soreness, fatigue, and a temporary decrease in performance. If the stress is maintained without proper recovery, overtraining can occur. However, if an athlete recovers adequately after a period of stress, or if the stressor is temporarily withdrawn, performance can rebound and increase beyond training levels; this is often coined the term supercompensation and is another driving principle behind periodization.

Stimulus-Fatigue-Recovery-Adaptation (SFRA)

GAS was originally created to describe a response to a general stressor, however has been critisized that it was not created specifically sports training. This resulted in a more refined concept, the SFRA model, to explain training stress and adaptations.

Taken from BretContreras.com. Example of the SFRA (or SRA) curve in the context of muscle hypertrophy.

Although similar to the GAS model, the SFRA model concept states that training stress is dependent on many factors such as intensity and volume of training. The greater the intensity or volume of the training, the greater the stressor is, resulting in a higher amount of fatigue AND adaptation. Contrastingly, if the intensity or volume of training is insufficient, fatigue will not accumulate but training adaptations will not be made! As an athlete, you must introduce yourself to a progressively larger and larger training stimulus, not too small where you won't see any benefits from it, or not too large that you're unable to recovery from it.

In layman's terms: every time you perform a training session (stimulus), you start to build up fatigue in the form of muscle soreness and lowered energy levels. As you consume enough food and get enough sleep (recovery), you are able to recover from your workout and come back fitter and stronger than before (adaptation). In the strength training realm, these concepts are commonly described as "progressive overloads" where you're looking to increase the total amount weight lifted or total number of reps lifted every workout or every week, and "rest days" where you back off on the training stress in order to give your body time to recover.

Fitness-Fatigue Model

The fitness-fatigue (F-F) model suggests that fitness and fatigue are inversely related, where strategies that maximize fitness and decrease fatigue will be the most optimal to improving sport performance. It is thought that when we introduce a training stressor, fitness adaptations and the accumulation of fatigue occur simultaneously. It is not until the stressor is withdrawn, where fatigue dissipates and fitness is increased. Unlike the previous 2 paradigms, the F-F model is able to differentiate between specific training stressors. An exercise that stresses the neuromuscular system (heavy deadlifts) may not neccessarily affect the aerobic energy system to the same degree as a 10km run would. A well-known example of the F-F model is the strategy of tapering; where training volume is dialed back in order to eliminate muscular fatigue and express maximal strength, power and endurance.

Note that all 3 of these paradigms are used simultaneously in modern day training periodization. Thanks to the access to technology we have today, the ability to monitor training variables and training stress has made these concepts more important and more effective. Even with that said, there are still people who believe periodization does not work any better than non-periodized programs or is a waste of time or practical to implement. Their beliefs holds some truths, however are still misguided at the end of the day. I will go into detail in later parts of this series.

For now, soak in the information and take a look at how your current training fits the concepts discussed. Thanks for reading!

5-Part Periodization Series Links:
Read Part 101: Introduction
Read Part 201: Training Variation
Read Part 202: Training Effect & Phases
Read Part 301: Review of Periodization Models
Read Part 401: The Complexities and Problems of Periodization Theory