Introduction
Exercise volume is the second most important aspect of our Exercise program, behind the Exercise intensity. While the intensity determines the quality of the stress stimulus, the volume represents the necessary evil. It is the initial amount of a stressful event, that is required in order for us to change. Because the volume of exercise not only denotes how much stress we expose to our body but also how much time we spend exercising, we would preferably want to optimize this variable, so as to not waste time and actually even slow down our rate of progress by doing too much. On the other hand, there needs to be enough of a volume to make a change. So finding the fine line between too little and too much is always a challenging procedure.
Definition of Exercise Volume
Exercise volume is simply stating how much exercise one performs over a period of time (usually over a week for practical reasons). There are many variables that together denote the total amount of our exercise volume:
- Training frequency or number of exercise sessions (for instance 3 workouts per week),
- Number of total exercises performed (12 exercises per workout, 4 pulling exercises, 4 pushing exercises, and 4 lower body exercises),
- Number of sets (a concluded unit of movement repetitions), performed for a particular exercise (let’s say we do 3 sets per each exercise) and
- Number of repetitions and/or time under tension per set (how long does each set last, for instance, 12 repetitions 2 seconds each total to 24 seconds per set).
If we accumulate all the examples in the brackets we would get a total of 42 minutes of mechanical work volume performed per week, or 14 minutes for our pulling muscles (back, biceps, forearms), 14 minutes for pushing muscles (chest, shoulders, triceps) and 14 minutes for our lower body muscles (thighs, glutes, hamstrings, and calves). And before we continue, it might be good to ask the following question: How much of those 42 minutes were required to produce the positive benefits gained from such a program?
Exercise Volume and Recovery
Managing how much volume our exercise program has is very important for the purpose of good recovery and time efficiency. Even when we are doing correct Exercise, which does not produce injuries and improves our muscle quality (in the long run) [1], the nature of any adaptation is that it requires a stressful stimulus. Anything stressful is in the short term a negative, from which our body needs to first recover and later compensate with an adaptive response. In the case of intense exercise, we break down proteins, which require rest and adequate nutrition to compensate for [2], [3].
It is only in the recovered state, where we can produce new positive adaptations. The physiological state, where we are not yet recovered, but still continue to exercise and in correspondence fail to demonstrate any progress is called overtraining [4]–[6]. It is the state of overtraining that we need to avoid because in that state our body is still fatigued from all the stress. And as the body is fatigued it can not perform well and in that respect, the stress stimulus the body can produce through exercise is weaker, non-existing, or even detrimental.
Exercise Induced Fatigue
Fatigue from exercise can be present at two sites:
- Fatigue of the muscles – peripheral or local fatigue and
- Fatigue of the nervous system – systemic or central fatigue.
At the muscular level, fatigue is expressed through empty glycogen reverse, damage to muscle fibers, and different types of inflammatory markers [7]. It takes on average 24 – 72 hours for the muscles to recover from fatigue. In some cases, when the lowering part of the movement is accentuated, it can even take a week [8], [9]. The adaptation or the growth to the new stress happens afterward.
At the nervous system, different neurotransmitters are being modulated (increase in serotonin and cortisol), which in effect (negatively) modulates the rate of motor-neuron firing [10]. This leads to a reduced ability to contract our skeletal muscles. If the nervous system is fatigued, the rate of muscular contractions will be lowered and the resistance we can handle will decrease [11], [12]. The nervous system fatigue takes between 2 – 3 days when one would look at the effect of a single exercise [13].
In relation to systemic fatigue, it is also very important to emphasize the connection between muscle size and the level of systemic fatigue. Namely, systemic fatigue also happens as a response to accumulated local fatigue [14]. In that regard, fatiguing larger muscles, like the glutes, the thighs, and our back, will more severely fatigue the nervous system, compared to fatiguing smaller muscles such as muscles in our arms, calves, and the neck for instance.
Interplay between Intensity and Volume
For any stress, we need two variables:
- Intensity and
- Volume or duration of exposure.
For an analogy, let’s take a look at building up a skin tan. We all understand that in order to build a tan, we require strong enough sunlight and spend the right amount of time on the sun. If we sunbathe for a short duration, our skin will not get darker. If we sunbathe in winter (where the sun rays are weaker), no matter the time, our skin will not get darker again. So there needs to be a high enough intensity of the sun rays and based on that intensity, the exposure to that sunlight needs to be long enough.
Intensity and volume are two tightly connected variables of our Exercise program. Long term, if we do too much exercise, our intensity will suffer since our body is fatigued and not able to produce intense muscular contractions. Similar effects can also be observed inside a workout as well. With every exercise performed, we accumulate more and more fatigue (systemic and local). Therefore, the first exercise we perform has the potential to produce the most intense stress stimulus, while with the last exercise the potential to produce a good stress stimulus is much lower.
Performing exercise in the fatigue state will lead to a lower quality stimulus and less progress in that exercise. The rate of fatigue buildup is also in a positive relationship with the intensity of exercise. The more intense the exercise is, the faster we accumulate fatigue. This leads to an important revelation: the more intense our exercise program, the less volume we can perform.
The Concept of Minimal Effective Dose
If we go back to the analogy of the sun, we understand that we are required to sunbathe on very sunny days for enough of a time. It is important to note, however, that overexposure to the sun will not make us darker faster. Once we reach the threshold of stress resistance at the current moment, we just get a burned skin which can lead to the skin simply peeling off, with no concrete darkening.
We also understand that we have an innate ability or genetic predisposition to sunray tolerance. Some of us are already born with more melanin and the son doesn’t burn us at all. Some of us can’t tolerate the sun and any exposure to it just makes us red and burned. And most of us are somewhere in between. So in that regard, we have an innate stress tolerance, which we take into consideratioin as to how much stress can we be exposed to and what kind of adaptation we can later attain.
If we want to continue building up the tan, we need to allow ourselves to recover from the first burn and continue building up melanin after higher levels have been established. And the same rules apply to improving our muscle quality i.e. building strength, muscle mass, neuronal connection, etc.
And the procedure, where we establish the right amount of time spent at the threshold of intensity, without vasting time or producing negative side effects is the concept of minimal effective dose.
Determining the correct Volume
Through experimentation, we need to establish when a particular combination of volume and intensity is enough, to allow us to recover inside our scheduled rest period. For instance, if we work out once per week, we would need to adjust the volume and the intensity so that one can demonstrate signs of recovery in the next workout session. And the most simple sign of adequate recovery is our performance.
Stated simply, if we progress through workouts, by demonstrating that we can handle a higher stressor (we are able to lift more weight, do more repetitions, or produce more force, while other exercise variables are the same), then our ratio between stress and recovery is sufficient. And in that regard, the aim of an efficient exercise program is to find the least amount of volume that will allow us to reach this threshold for progress, i.e. the minimal effective dose. So if we can demonstrate the same rate of progress, while doing twice as little volume, then that exercise program is twice as more efficient and productive.
In that regard, when constructing a workout program and deciding about the volume, take into consideration the following questions:
- Which muscles I would need to improve (if not all of them)
- Which exercises cover the targeted muscles from above,
- Which exercises efficiently fatigue multiple muscles at once to reduce the total amount of exercise,
- What is the least amount of exercise required, to engage and fatigue (to a deep enough level), the targeted muscles.
Defining your Exercise List
The goal of a well-structured exercise program is to provide most of our skeletal muscles with an intense stimulus for improvement. In that regard, we need to do select exercises that will efficiently fatigue these muscles, preferably with the least amount of total volume.
As was mentioned in previous sections, we can express exercise volume as the total amount of mechanical tension being placed on our muscles. To measure our total volume we should be mindful of all the existing muscles and denote, which of them have been efficiently fatigued through our exercise program. And so we would rather than talking about the whole body exercise volume, talk about volume for each muscle group.
In that regard, we do not need to do specialized exercises for each individual muscle group. While the level of intensity will be high doing it that way, we will require a lot of exercises and correspondingly a lot of time to finish our workouts. In that respect, it is best to first group exercises into the basic categories:
- pushing (chest, shoulders, triceps)
- pulling (back, biceps, forearms)
- squatting (glutes, thighs, hamstrings, calves)
Most of our exercises will fit into any of these three categories. So we count how much total mechanical tension we do with each of the groups mentioned before. A good guide is to have an equal distribution of mechanical tensions.
For each group, we select 1 – 3 exercises. The best candidates are multi-joint exercises, where all of the muscles in each group are engaged and fatigued at a similar rate in each movement.
On top of a few multi-joint exercises, we might add additional isolation exercises, which will allow us to fatigue the muscles, we weren’t able to with the multi-joint movements. This goes especially for the muscles in the neck, calves, forearms, hip-flexors, etc.
Based on how many total exercises have been selected, we might need to split them into multiple workouts. In general, it is our recommendation to do between 3 – 12 exercises per workout, and between 3 – 24 exercises per week. While this might be quite a wide range, it strongly depends on the individual, his lifestyle, and his goals.
Applying the concept of Minimal Effective Dose
In Exercise, the stress intensity is derived from the number of motor units activated and fatigued through the exercise protocol [15]. And to reach an adequate level of stress intensity, we need to seek the point of momentary muscular failure. However, once we reach a point of momentary muscular failure with a particular muscle group (or groups in a compound movement), the stress stimulus is adequate to promote an adaptive response [16].
However, as it was established through multiple research, the exercise volume for each muscle group needs to be at least 30 seconds before one reaches the point of muscular failure. This will make sure that we accumulate fiber damage as well as metabolic signaling for improved muscle strength and size [15].
Finally, going to muscular failure improves the time efficiency of our workouts by multifold, since we actively seek to reach the stress threshold through an aggressive accumulation of fatigue. And this can be achieved in a single set.
To conclude, an efficient exercise program can be constructed by using only a handful of exercises, such as:
- a squat
- a deadlift
- vertical press
- vertical row
- horizontal press
- horizontal row.
Doing each exercise width a weight that allows you to reach the point of momentary muscular failure between 30 – 120 seconds, you would need to do only 1 set per exercise. In total, this workout would take you between 10 – 20 minutes (including resting and setting up your equipment). Because all the muscles would be fatigued thoroughly, even 1 single workout per week would produce admirable results if performed consistently.
For comparison, look at the table below comparing the volume of a typical weight lifting program compared to an exercise program based on the principles of High-Intensity Training and a Single Set to Failure approach.
| Standard Resistance Training | Correct Exercies | |
|---|---|---|
|
Number of workouts per week |
3 - 5 |
1 - 3 |
|
Number of exercises per workout |
6 - 20 |
3 - 12 |
|
Number of sets per exercise |
3 - 5 |
1 |
|
Time under tension per set |
10 - 40 sec |
30 - 120 sec |
|
Typical length of a single workout |
30 - 120 min |
15 - 40 min |
|
Typical time investment per week |
1 - 10 hours |
10 - 90 minutes |
Conclusions
In this blog post, we have looked at the concept of Exercise volume. Exercise volume defines how much total mechanical tension, do we expose to our musculature, which in effect fatigues our muscles and our nervous system.
We have established that for an effective exercise the intensity and volume need to be correctly adjusted to fit our recovery abilities.
We have also defined the nature of stress adaptation and the relationship between stress intensity and its duration (negative relationship).
Finally, we have looked at the concept of minimum effective dose, as the main aim to go for, where recovery, productivity, and time efficiency are of priority. With this, we also saw, how an approach of high-intensity training, leads to a much more time-efficient and sustainable Exercise approach.
