Strength and conditioning practice has four key principles, which are progressive overload, specificity, individuality, and variety. Almost all research and coaching practice supports these principles, and while they are not fundamental laws, they are exceptionally good guidelines.
Periodization is one way in which the principle of variety can be applied to an athletic development program.
There are other ways of incorporating variety into a training program, which include using random or quasi-random elements (like instinctive training), unplanned elements (like autoregulation), or non-timetabled elements (like bodybuilding programs that stop program cycles only when progression on an exercise ends).
Such approaches would rarely be described as periodized programs, and therefore help us to refine what we mean by periodization in practice, which is the “incorporation of non-random, pre-planned, and timetabled variety into a workout program, in order to enhance gains in athletic performance and reduce the risk of overtraining.”
But how might periodization achieve these two goals?
Let’s start with reducing the risk of overtraining, since that actually helps us figure out how periodization might improve performance.
#1. How might periodization reduce the risk of overtraining?
The general adaptation syndrome
Understanding how the general adaptation syndrome (GAS) might apply to strength training helps us see how periodization (and other methods of applying the principle of variety) can reduce the risk of overtraining.
The GAS describes a generalized stress response that is observed in animals when they are exposed to a stressor. Athletes have a finite amount of adaptation energy that they can devote to this generalized stress response, and exceeding this capacity leads to exhaustion (overtraining).
Some strength training workouts and programs produce muscle damage (such as high volume bodybuilding workouts). This muscle damage seems to lead to a generalized stress response, and such workouts can therefore be modeled by a GAS framework. However, other workouts do not cause any muscle damage (such as power training) or cause minimal muscle damage (such as low volume maximum strength training).
In this model, the purpose of periodization is to reduce the chances of arriving at the exhaustion phase of the GAS framework. In order to do this, it must manage muscle damage.
Reducing the risk of exhaustion
Periodization models might reduce the risk of exhaustion by:
- Limiting exposure to muscle damage, by putting most of the muscle-damaging workouts into a single block, after which less-damaging workouts are performed in other blocks (block or linear periodization);
- Increasing recovery time between muscle-damaging workouts, by splitting workouts out into different types (high volume bodybuilding and low volume maximum strength), and interspersing muscle-damaging workouts with less-damaging workouts (undulating periodization); and
- Reducing the exposure to other stressors other than the one associated with the targeted adaptation, by focusing on improving only one muscle group or strength quality at a time, while putting the others on maintenance (or stopping them entirely, as is more commonly done in athletic development for some reason).
Ultimately, in each case, the periodization approach is limiting the overall exposure of the athlete to muscle-damaging workouts, either by (1) putting them all in one block of time, (2) spreading them out over a longer time, or (3) focusing them on one muscle group or strength quality.
But how does this apply to the individual athlete?
Application to the individual
When the periodization model “fits” the athlete’s recovery profile perfectly, by allowing exactly the right amount of recovery time between muscle-damaging workouts, then the athlete will progress at the fastest possible rate while not reaching the exhaustion phase.
On the other hand, if the periodization model does not allow enough recovery time between muscle-damaging workouts, then the athlete will reach exhaustion, and the training approach will have failed.
Since athletes have quite individual recovery capacities and life events can influence recovery capacity, the same periodization model will not work optimally for every athlete, and will also not work optimally for the same athlete on two separate occasions.
#2. How might periodization enhance gains in performance?
There are two completely different ways in which periodization can potentially enhance performance improvements, depending on the model that is chosen.
- Block or linear periodization models — allow the athlete to focus all of their efforts on improving a single strength quality. This model is a sprint to accumulate the greatest possible gains before risking exhaustion. This approach has potential for large improvements to be made, but it runs the risk that each strength quality will revert back to its previous levels in later blocks in which other strength qualities are trained, meaning that the actual gains in this strength quality are actually zero when measured just prior to competition. In fact, this is often exactly what happens.
- Undulating periodization models — allow the athlete to distribute their efforts on improving multiple strength qualities, without losing gains made in any domain. This model is a marathon, in which exhaustion is less likely but gains are slow to arrive. Indeed, this model has the disadvantage that efforts may not be focused enough to achieve gains in any domain, or that progress occurs so slowly as to be demoralizing.
Either way, periodization works to enhance athletic performance by allowing the athlete to train a strength quality that requires producing muscle damage more regularly than would otherwise be possible in an unvarying program. It either does this by limiting exposure to a few weeks, distributing the workouts further apart, or limiting the type of strength quality to a single domain.
Essentially, this is the same set of mechanisms that reduce the risk of the athlete reaching exhaustion, and it is therefore subject to the same criticisms, which are that it does not necessarily take into account individual variability or the changes in external stressors from one day to the next.
How can we make periodization better?
Hopefully, by now it is clear that periodization is a tool to help athletes allow the greatest exposure to muscle-damaging workouts (which are necessary in order to improve certain strength qualities), while avoiding exhaustion. Yet, there are other tools, some of which can be used in combination with periodization.
For example, autonomy over aspects of a workout (even aspects that do not affect the actual exercises or workload) can increase workout performance and potentially long-term improvements, by increasing the expectation of positive outcomes, self-efficacy, and intrinsic motivation. It thereby allows athletes to maintain their attentional focus on the goal of the task, and not engage in regulating negative emotional reactions caused by the perception of a lack of control over their immediate environment. Such negative emotions likely function as an external stressor, and reduce adaptation energy.
Also, autoregulation using either external measures (bar speed) or internal measures (rating of perceived exertion) can provide an indicator of whether workouts should be modified on the day to take into account the readiness of the athlete to perform. Indeed, simple tests of jump height before a lower body workout can predict whether an athlete will be able to achieve the same or greater volumes compared to the previous workout.
A simple but powerful autoregulatory measure is to record progression from the previous workout (either in terms of reps, weight, or bar speed). The recovery of strength is the best measure of whether muscle damage has been fully repaired since the previous workout. Thus, if no progress has been made, then the athlete is not fully recovered, and subsequent workouts may need to be further apart, or it may be necessary to stop focusing on that particular strength quality, and start focusing on a different one.
This approach is not possible with linear periodization models, which change the percentage of 1RM in each workout, which makes the use of readiness tests more important when using that approach.
What does this mean in practice?
To maximize the benefits of periodization in practice, it helps to do the following:
- Decide whether you want to develop strength qualities as a sprint (and then try and maintain them) or as a marathon. A sprint approach will lead you to use block or linear periodization models. A marathon approach means using undulating periodization. The right approach may often depend on the psychology of how the athlete handles the rate of progress, the ability of the athlete to maintain gains once they are made, and the competition schedule.
- Monitor whether the periodization of training is working or not, as recovery capacity can vary depending on the individual as well as from day-to-day because of external stressors. The simplest tool is whether progression (load, reps, or bar speed) is being made from one workout to the next. If the particular periodization model makes that difficult, readiness tests are essential.
- Make use of other tools to help reduce external stressors, such as autonomy. This can be over almost any aspect of the workout or training environment, not necessarily the choice of exercises or rep ranges.
What is the takeaway?
Periodization can be seen as a tool for managing the cumulative impact of muscle damage on our strength training goals. Some muscle damage is a necessary evil for developing certain strength qualities, but too much probably leads to exhaustion and overtraining.
Periodization models work as either sprints or marathons to attain each strength quality. If you periodize your training, be sure to pick the right one for you. Either way, it helps to monitor whether the periodization model is doing what it is supposed to do, by helping you recover between workouts. And obviously, don’t forget to make use of other tools that help manage external stressors, such as autonomy.