Is doing more volume really better for muscle growth?
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Yes, more volume really is better for muscle growth. It absolutely does have a positive relationship with hypertrophy. Recently, this has become more contested with the resurgence of lower volume training and its proponents (like Jordan Peters, fans of Dorian Yates/HIT, etc.). This is because there is a caveat to more volume = more muscle growth: you need to be able to recover.
Warning: this article contains unprecedented amounts of MS Paint and plagiarism. If you’re not happy with that, read ahead at your own risk.
Understanding what volume is and how it relates to growth
For the purpose of this article, volume will be defined as hard sets/week/muscle group. Hard is a set that is taken within about 5 repetitions from concentric failure – when you can’t lift the weight up anymore with good technique. While that definition of failure has several limitations, it is still better than any of its alternatives. As you go through this article, however, keep in mind that volume has had other definitions. It can also be defined as Work (Work = Force * Distance) – that is to say, it is the energy expenditure of training. I’ll get back to both definitions.
For now, what you should know is that volume is positively related to growth; taken as a whole, the evidence suggests that, up to a certain amount of volume, more volume does lead to more growth.
Let me show you what that looks like.
The Inverted U Hypothesis
Enter: the inverted U hypothesis. While I haven’t seen this formalized in research (I’ve seen it in psychological arousal and performance research, but not hypertrophy), it probably applies to muscle growth and volume VERY well.
Figure 1. The inverted-U hypothesis.
What does the inverted U hypothesis state? Simply put – when volume is low, muscle growth is low. Then, as volume increases, muscle growth increases, until you reach a peak at optimal volumes. From there, if volume is increased further, muscle growth decreases again (Figure 1).
Now, before you roll your eyes and say that the model is simplistic – you’re right. It is. Nonetheless, it’s a useful conceptual tool. Importantly, the above graph represents a single response. That is to say – that could be one person’s response to volume, or it could be an average. Let’s assume it’s an average response of a group of lifters.
What would happen, if, instead of just showing you the average response, we showed you EACH of the responses? Well, maybe that would look something like this:
Figure 2. Multiple Inverted-U curves.
Take a minute to look at each of these and think about what this means.
In figure 2, Individuals 1, 2 and 3 all maintain muscle at different volumes (in sets/week/muscle group). Not just that – they also optimally grow at different volumes.
Do different people grow best from different amounts of volume?
Hint: Yes they do, and it’s because different people are different.
More specifically, different people not only have differing genetics but also stress levels, training statuses, sleep habits, nutritional habits and lifestyles. These ALL play a role in influencing how well someone can recover from training.
Now, here’s the important part; because different people have different recovery abilities, the amount of VOLUME people should do is also different. Volume (mainly when defined as Work) is the main contributor to fatigue. Are there other contributors to fatigue? Yes, there certainly are. Here’s a brief, non-exhaustive list of them:
1. Absolute Intensity (% of 1RM)
2. Relative Intensity (proximity to failure/exhaustion)
3. Training Density (volume/unit of time)
4. Excessive Psychological Stress (distress)
5. Etc.
The Sink Analogy
I have no idea who to credit for this (maybe it’s Mike Tuscherer, or it might be Greg Nuckols).
Say you have a sink (Figure 4, below). There’s tap water splashing down into the sink, and a drainage system to make sure the sink doesn’t overflow. The sink is your body. The tap water’s volume is training volume. The drain is your ability to recover. The rate of water flow through the system is your rate of muscle growth.
Figure 4. I blatantly ripped these sink pictures off an article by Greg Nuckols at rippedbody.com. To my credit, though, I did edit them a bit. My drawing skills just aren’t good enough to draw a reasonable-looking sink.
If you have a super tiny drain, you probably can’t fully turn on the tap or the sink will flood and overflow (overtraining). The rate of water flow through the system won’t be maximised because of the spill and your results won’t be optimal. (Figure 5, below)
Figure 5.
Conversely, if you have a huge, wide drain, but you only just barely turn on the tap, the sink will never accumulate any water (undertraining) (Figure 6, below). The rate of water flow through the system won’t be maximised because there just isn’t enough water splashing into the sink and your results won’t be optimal. It’d work better if you turned the tap on more fully.
Figure 6.
How do you optimally progress, then?
You tailor how much you turn on the tap (how much volume you train with) to how much water your drain can drain (recovery abilities) to maximise the rate of water flow (rate of muscle growth) without spilling water.
Is recovering even that important?
Yes, it is – because you can only improve once you’re done recovering.
The Stimulus Recovery Adaptation principle is an integral principle to understanding how you improve in response to training.
Figure 7. Taken from the Scientific Principles of Strength Training ebook by Renaissance Periodization and Chad Wesley Smith. Highly recommended.
Let me explain what the graph means. Initially, you’re at rest. Then, you go train, and enter the stimulus stage. By training, you fatigue your body, but you also disrupt its normal (homeostatic) state, stimulating it to adapt. Once you’re done training, the recovery stage begins – during this stage, your body’s systems slowly recover, until they reach the state they were in before you trained. This phase is called recovery because you return to your pre-disruption state. Finally, the adaptation stage can begin. After your body has finished recovering, it will begin adapting. This is where muscle growth, strength gains or endurance improvements occur. This stage only occurs once recovery is completed, so it is crucial to properly dose volume and allow for enough time between sessions to allow adaptation to occur (usually, though there are some exceptions). You only get better once recovery is completed.
Crucially, because volume is one of the biggest if not the biggest factors in inducing both stimulus and fatigue, when volume is increased, recovery and adaptation take longer to complete.
To summarize - more volume is better for growth, with one caveat: usually, you need to at least fully recover between sessions. How much volume that is for you as an individual can be vastly different from other people, so use trial and error to optimize things.