Advanced Trainees Benefit from Increased Training Volume! Greater & Steadier Strength Gains with 8 Sets of Squats. Plus: Over 6 Weeks, 1 Set and 4 Sets Equally (In-)Effective.

Image 1: Look at his legs, Ronnie Coleman must have done something right... and guess what, the study at hand suggests that part of it could have been his insane training volume.
Studies on different exercise protocols are scarce and many, if not most of them are conducted with obese, sick, elderly or otherwise physically impaired individuals. And even the infamous "recreationally active" study participants are not a very suitable model for aspring physical culturists like you and me *rofl*, right? Daniel W. Robbins, Paul W.M. Marshall and Megan McEwen, three researchers from the University of Sydney, the University of Western Sidney (obviously not identical to the former!?) and the University of Auckland obviously felt the same, when they set out to investigate the effects of a 6-week training intervention with different training volumes (as measured by sets per workout) on the lower-body strength (barbell squat) of 31 experienced (mean training experience ~6.7y) strength trainees (Robbins. 2012). By setting a minimum barbell squat performance of 130% of their own body weight as an inclusion criteria for their subjects, the scientists also made sure that none of their male participants (mean age 27.8y) had only been going to the gym to hit on the ladies at least twice a week for the last 2 years.

Finally a study on subjects "like you and me" ;-)

After an initial 2-week standardization phase with 9 training sessions on a 3-way split, in the course of which the subjects did not squat, they were randomized to one of the three volume conditions (Low  = 1-Set; Medium = 4-Sets; High = 8-Sets, cf. figure 1).
Figure 1: Outline of the training protocol that was used in the study (adapted from Robbins. 2012)
In the following 6 weeks, all subjects trained according to a 2-way split program (cf. figure 1), which differed only in the amount of working sets the subjects had to perform on the regular barbell squat, the only lower body exercise in their programs. The lower leg strength of the study participants was assessed at 4 time-points: (1) at the end of the initial standardization period, (2) after the third week and (3) at the end of the 6-week volume manipulation phase, and (4) after the completion of the 4-week post-program phase.
Figure 2: Repetitions per set in the first set and average repetitions per set in all working sets (left) and minimal (avg. - 1x standard deviation) and maximal (avg. +1SD) total number of barbell squat repetitions the subjects in the 1-, 4- and 8-SET groups performed during the 6-week volume manipulation phase (data adapted from Robbins. 2012)
As the data in figure 2 goes to show, the comparatively higher training volume in the 4- and 8-SET (cf. figure 2, right) conditions took a toll not only on the average number of repetitions per set, but also on the the number of reps they cranked out on their first working set of barbell squats. Robbins et al. attribute this effect to the psychological burden of having to perform another 3, respectively 7 sets and advise practitioners (i.e. trainers) to be "cognizant of this [tendency to] 'hold back' in early sets to perform better in later sets", when they design a program.

There is no "one size fits it all" volume, but ...

If we now take a look at the actual study outcome in figure 3 it becomes obvious that at least a certain sub-group of those "practitioners" will probably also have to revise their approach to building strength from a very low, to a higher volume approach. After all, the 1-SET group did not only register the smallest gains in lower body strength, a statistically significant increase in strength (as denoted by the asterisk "*" in figure 3) did occur only in the second half of the intervention period, whereas the subjects in both the 4- and 8-SET groups experienced statistically significant strength gains right from the start.
Figure 3: Maximal squat strength (kg) and relative increase in squat strength during different periods of the study; * statistically different from baseline, # statistically different from 1-SET group (data adapted from Robbins. 2012)
In the 4-SET group, on the other hand, we do see a statistically significant increase in strength in the first 3 weeks of the intervention period, already. In the following 3 weeks, however, the strength of the subjects in the 4-SET group stagnated, so that the overall increase in lower body strength of the 1-SET and 4-SET groups at the end of the both the 6-week volume adaptation as well as the 4-week post program phase did not show statistically significant differences. This lead Robbins et al. to speculate that...
[...] over the longer 6-week period, the accumulated volume and associated training stimulus were sufficient to elicit an effect similar to that elicited via the 4-SET condition
This does yet not change the significantly greater and above all steady increases in lower body strength in the 8-SET group, which - somewhat surprisingly - continued even into the post 4-week post program phase, when the study participants were again training according to identical full-body workout plans.

... for advanced trainees a higher volume appears to illicit favorable lower body strength gains.

Image 2: Only a few "gifted" and often "artificially enhanced" athletes can train still intense, when they increase their training volume to Coleman'ish or in this case Tom Platz'ish levels,
Against that background the main take-home-message of the study appears to be that advanced strength athletes benefit from an increase in training volume from 1 or 4 to a still very reasonable level of 8 working sets per workout.

These results do yet  not justify the insane 2h+ "mammoth" leg workouts especially bony beginners (I would hope they are beginners, as they surely look like that) like to do to "bring up their wheels" - I mean, come on, even if you use Coleman'ish "supplements" doing 5 sets of squats, 4 sets of leg presses, 3 sets of lunges, 3 sets of leg extensions and whatever else may come to your mind will either burn you out within 2 weeks, or amplify the aforementioned tendency "to hold back" to a degree that will turn your strength into a whacky cardio workout.

So, please bear in mind: If some is good and more is better, this rarely means that even more would be even better... but I guess this is enough "wise-assing" for today ;-)
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