The Driver Of Growth: Volume
If you are someone who is chasing maximum muscle growth, then there is one thing for certain that you absolutely need to think about when it comes to your training, and that is volume load. Now some of you might be thinking: this sounds complex! But really, is isn’t! When we talk about volume load, we simply mean the number of repetitions you perform for a given weight, across of defined number of sets (volume = reps x sets x weight). Nice and simple. The research now is pretty clear cut, if you want maximum muscle growth, then the total volume of work you perform over time will be the top factor to consider. In the world of muscular hypertrophy gains, this total amount of work performed is your top ticket to ultimate growth. Although exactly how much work is needed, is still a mystery to us!
What The Science Has Said
Simply put, the more volume you perform over time, the more muscle growth you can expect to gain (at least to a certain point). If your goal is increased muscular hypertrophy, then your training should reflect this by increasing your volumes of work over time. If no change in total volume occurs in your training, then you will not grow. It is that simple. There is good evidence to suggest that greater training volumes enhance muscle growth through volume-dependent changes in various biological pathways, which are involved in protein synthesis signalling. Terzis et al (2010) were able to demonstrate that increases in the number of leg press exercise training sets, led to statistically significant increases in protein signalling activity. This suggested that higher volumes could lead to increased muscle growth through changes in signalling activity. However, it is important to keep in mind that these acute changes in protein signalling pathways do not necessarily reflect the long-term changes in muscular hypertrophy (Mitchell et al. 2014).
Terzis et al. (2010) Figures show the level of phosphorylation of key proteins involved in protein synthesis signalling in response to increases in the numer of exercise sets. This suggested that higher levels of training volume could lead to greater levels of muscular hypertrophy through an increase in protein signalling.
Mitchell et al. (2014). Figures show that there were no correlation between actue muscle protein synthesis in any of the time periods measured and muscle volume. Therfore, the results by Terzis et al. (2010) must be interpreted with circumspection.
Pooled research has clearly shown that increases in volume do lead to greater gains in muscular hypertrophy. Schoenfeld et al (2016) collected together a series of studies that investigated the effects of increasing weekly number of sets per muscle group (<5, 5-9, or 10+) on muscle growth. After having calculated the mean effect sizes between the set groups, Schoenfeld et al. did observe an incremental dose-response relationship between weekly training volumes and greater muscular hypertrophy. The mean effect sizes were 0.307 for <5 weekly sets, 0.378 for 5-9 weekly sets, and 0.520 for 10+ weekly sets, which corresponded to percentage gains of 5.4%, 6.6% and 9.8% respectively. These results supported the idea that higher weekly volumes do lead to greater muscle gains. However, although this research showed an important volume-hypertrophy relationship, the fact that weekly sets did not exceed 12 sets per muscle group, leaves an important question to be answered: where is the upper threshold point for this relationship? We do not know this at the moment. It is important to note here that all individuals are different. Depending on their training experience, tolerance to volumes and recovery abilities, the number of needed weekly sets per muscle group are likely to be vastly different between individuals.
Schoenfeld et al. (2016). Figure shows the pooling of studies invetigating the effects of weekly volume (as number of sets per muscle group) on muscular hypertrophy. The results tended to favor higher volumes (more number of sets) over lower volumes (lower number of sets) for enhancing muscle growth.
In attempting to answer the threshold point question, a study by Wernbom et al. (2007) identified a possible plateau point in muscular hypertrophy. Wernbom et al. found that the cross-sectional area of the elbow flexors increased from 0.15% per day when 7 through to 38 repetitions were performed per session. This increased to 0.26% per day when 42 through to 66 repetitions were performed per session. Interestingly however, it was observed that this increase reversed to 0.18% with volumes in the range of 74 through to 120 repetitions per session. These results suggested that increasing training volumes to a point can increase muscle growth, but only to a point. Past this threshold point, muscular gains appear to regress. Although not suggested in this study, it is likely that a point had been reached in which high volumes led to a state of far overreaching or, overtraining. It is likely that at this point, the amount of stress generated through higher volumes started to outpace the body’s ability to recover from this work. As always, it is important to keep in mind that this threshold point will be different for everyone. This again will be dependent on their training experience, tolerability to volume and recovery abilities. But, this research does highlight the possibility of a threshold point existing.
Wernbom et al. (2007). Figure shows the influence of volume (as number of repetitions) per session on cross sectional area of the elbow flexors. There was an increase in cross-sectional area with the number of repetitions up to a point, then beyond this, there was a regression in muscle growth. This suggested the presence of a threshold point (maximal effective volume). Beyond this point, more volume was simply causing possibly overtraining.
More Gains, But Only To A Point
The research that has been done up to this point has highlighted a clear trend: more training volume ultimately leads to more muscular growth. Furthermore, this research has suggested that this trend is not infinite, and indeed you can do too much volume. This threshold point of too much volume however, still needs a lot more research to give us an idea of where it might actually lie. No one really knows! Given that muscle growth depends on muscle protein synthesis out-competing muscle protein breakdown, it is likely that these higher volumes over time shift this balance in favor of protein synthesis. This shift would then allow for the increased assembly of muscle building proteins which would lead to more growth. However, in line with a potential threshold point, too much volume is likely to shift the balance again to favor muscle protein breakdown. This might lead to the regression in hypertrophy seen at very high volumes.
In terms of training, the answer is obvious: more volume over time for more gains. If your training does not have you increase your overall volume over time, it is going to be pretty difficult to maximise your gains. However, the job is to maximise volume without going over a tipping point and wiping yourself out. That is not good for anyone! The best way of ensuring you can maximise training volumes over time without under-recovering, is to periodize your training program. By periodizing your training into dedicated higher and lower volume periods, you maximise your bodies response to the training stimuli, while giving recovery a chance to keep pace with the work you are doing.