|Image 1: The green dots that are crowding left and right from the blue myonucleus are the satellite cells (Hanssen. 2012)|
Full body training 3x /week: How many sets are optimal?
For their study, Hanssen et al. recruited twenty two healthy untrained men (age 26.5y; height: 181.8cm; weight: 81kg) and assigned them to one out of two full-body workouts, with identical exercises (leg press, leg extension, leg curl, seated chest press, seated rowing, latissimus pull-down, biceps curl, and shoulder press), but different amounts of sets for a given body part:
- 3x Legs & 1x Upper Body: Trainees in this group performed 3 sets for each of the leg exercises and 1 set for the upper body exercises
- 1x Legs & 3x Upper Body: Trainees in this group performed 1 set for each of the leg exercises and 3 sets for each of the upper body exercises
Participants were encouraged to continuously increase their RM loads during the intervention and they were allowed assistance on the last repetition.In addition to the three strength training sessions per week, the participants were allowed to perform one (not more!) additional steady-state cardio session. And while this may help with standardization, my mathematical skills tell me that the 3L-1UB group performed only 14 sets per workout, while the 1L-3UB group performed 18 sets, simply because the number of lower and upper body exercises was not identical. Now, everyone who does not claim that he or she does not need to train legs (for whatever stupid reason) will know leg training is much more draining than upper body workouts, so "intensity-wise" the workouts were probably still identical.
Single vs. multiple-set training? Nothing new or exciting if it was not for the specific data
We have seen similar studies before - most of them with the same, very unfortunate limitation of being performed on strength training novices, by the way - and the results of this study would hardly be exciting, if it were not for the sheer amount of data Hansson et al. recorded:
- muscle strength and muscle fiber size,
- the number of satellite cells and number of satellite cells positive for myogenin and MyoD,
- the number of myonuclei, myogenin and MyoD content of muscle samples, and
- myostatin and a whole host of growth factors, namely IGF-1, MGF, HGF, FGF2 and VEGF
|Image 2: If those acronyms don't ring a bell, click here to learn more.|
|Figure 1: Changes in 1RM strength and fiber area after 11 weeks on the training regimen with different set schemes (data calculated based on Hanssen. 2012)|
|Figure 2: Relative changes in myonuclei number per muscle fiber and the number of satellite cells after 2 and 11 (post) weeks of the training intervention (data calculated based on Hanssen. 2012)|
The novel finding in our study was the early increase in the proportion of activated satellite cells, the early increase in total number of satellite cells and the dependence on training volume in the leg muscle. The number of activated satellite cells, indicated by myoD and myogenin expression, increased from ~2% before training to 6–10% 2 weeks into the intervention.
So as "novel" as this finding may be, it is still somewhat unsatisfying for experienced strength trainees, who will have to rely on the hypothesis that their response will be an ameliorated version of the "late" growth response in the study at hand, which would support my personal observation that 3x3 i.e. three exercises à three sets per body part is at the lower end of the "optimal" volume continuum for advanced trainees. A volume continuum, by the way, that is capped at 12-15 sets for the largest body parst, i.e. legs and back and does by no means extent into the "insanity realm", where people perform 20 sets for biceps and 20 working sets for triceps on a 5-day body-part split.
Surprise: No statistical significant differences in growth factors
What I found quite surprising though, is that this advantage of 3- vs. 1-set training was not reflected by greater increases in myostatin and/or MGF (want to know more about MGF, click here for the pertinent installment of the Intermittent Thoughts). MGF was even higher in the vastus of the 1 set group and the smaller incline in myostatin levels in the 3-set group (1.1x vs. 1.8x) did not reach statistical significance.
|Figure 3: Changes in mRNA levels of myostatin, IGF-1, MGF, HGF, FGF2, and VEGF in the 10 subjects with the largest satellite cell response (seven from 3L-1UB and three from 1L-3UB; data adapted from Hanssen. 2012)|
And while it was to be expected that the expression of those growth factors would decline over the course of the 11-week intervention period, I am honestly wondering, whether the decrease in reps from 10 (initial two weeks) to 8 and subsequently 7 reps per set had anything to do with it... but I guess, this is an issue for the next study, about which, you will read nowhere else than right here, at the SuppVersity, the place where bro- and pro-science unite in the spirit of true wisdom - but I guess you know that by now, don't you? ;-)