Recently, I have created a number of infographics about progressive overload, because the concept is not well-understood. This short blog post sets them out in order, which makes the logic easier to follow.
#1. What is progressive overload?
Progressive overload is a change in training variables over time that allows us to match a more challenging workout with the new level of strength that is caused by new myofibrils forming inside muscle fibers.
If we don't match each new level of strength with a greater challenge, then some motor units (and therefore some muscle fibers) will not be trained as effectively. Therefore, it is essential that each workout is slightly more difficult than the previous one.
#2. Why is progressive overload so important?
#2. Progressive overload is the *only* way that we can detect whether a strength training program is actually working. This is mainly because central nervous system (CNS) fatigue can occur after a workout for several days, preventing us from obtaining adaptations from later workouts. Thus, if we are not careful, we could easily do hard workouts that have absolutely no beneficial effects whatsoever. However, if we are achieving progressive overload, then we know that adaptations must be happening.
#3. How can we safeguard progressive overload?
Given how important progressive overload is both for achieving adaptations to strength training and also monitoring those adaptations, it is essential that we are certain about whether it is occurring. Yet, poor control over our training variables and workout conditions can fool us into thinking progressive overload is happening when it is not.
#4. What should we do when progressive overload is no longer possible?
Many lifters change exercises in a training program when they stop improving without consideration for *why* they have stopped improving. Essentially, there are three possibilities: (1) the volume is not high enough, (2) the recovery period is not long enough, and (3) the exercise has genuinely reached its capacity for producing strength gains, perhaps due to regional hypertrophy.
This flow chart shows how to test each of these hypotheses in turn, so that progress can be made for longer.
#5. What training variables can be altered to cause progressive overload?
Strength training workouts cause adaptations if they have worked as intended. During bodybuilding training, the main adaptation is an increase in muscle size, caused by an increase in the number of myofibrils in parallel inside each muscle fiber. The increase in the number of myofibrils causes an increase in the ability of the muscle to produce force.
Alongside the other adaptations that we achieve after an effective workout, an increase in muscle size allows us to lift an increased weight for a given number of reps or to do an increased number of reps with a given weight. By programming and performing an increase in the number of reps or weight in our next workout, we can match our improved capacity for performance with an increased requirement. This is the essence of progressive overload.
However, increases in training volume (the number of sets) do not match our improved capacity for performance with an increased requirement, since we can achieve increases in volume without any adaptations happening. All we have to do is stay in the gym a little longer.