"10x3 = 3x10 < 20x3"? The Mathematics of Optimal Set and Rep Ranges for Maximal Increases in Sleeve Size

Image 1: Going for the pump was Arnold's way
to biceps peak and size, but is that "optimal"?

How many sets do you do, when you are at the gym? How many repetitions (reps) each? And are you sure that this is the "right" way to train? No? Well I guess then you will be interested in the results of a study from the School of Exercise, Biomedical and Health Sciences at the Edith Cowan University in Joondalup, Western Australia ( Chan. 2011), for which Roy Yang Han Chan (I hope I did not mix up name and surname, here ;-) recruited 10 non-resistance trained men to investigate the effects of different set/rep schemes on muscle strength, range of motion  (ROM),  muscle  cross  sectional  area  (CSA),  muscle  soreness  and  plasma  creatine kinase  (CK)  activity after two bouts of eccentric biceps curls (see illustration 1 for exact study setup).

Illustration 1: Setup of the 4 training bouts the 10 subjects of the study participated in (according to Chan. 2011)

Now, "non-resistance trained" subjects (mean ± SD age: 26.1 ± 4.1 y, height: 173.1 ± 6.1 cm, body weight: 72.4 ± 9.1 kg)  and training on just two occasions, are not exactly constituents of a highly significant study protocol. In view of the scarcity of data on what some trainers consider the holy grail of training theory, the finding that

Maximal  voluntary  contraction  strength,  ROM,  biceps  brachii  CSA [cross sectional area],  muscle soreness and plasma CK [creatine kinase - leakage of this enzyme from the muscle is a measure of muscle damage] activity changed significantly after the first bouts without significant differences  between  3x10  and  10x3,  and  changes  in  the  measures  following  20x3  were similar  between  arms.  No  significant  differences  in  the  changes  of  the  criterion  measures were  evident  between  bouts.the  set-repetition  configuration  had little effect on muscle damage, which was likely to be due to similar peak torques produced during  exercise  between  the  3x10  and  10x3  bouts.

The question we have to answer now, is "How representative is this data?" In the previous paragraph I already mentioned the first fundamental flaw of the study: the subject selection. "Why on earth", you may be asking yourself rightly, "Why did this Australian exclude resistance trained subjects from his study and chose subjects with 4.5inch arms? Isn't it obvious that these bonsai-guns will grow no-matter what those guys would do in the gym?" And, yes that is exactly the case and, at the same time though, also the reason why, time-and-again, we see those studies done with "resistance training virgins" - due to the completely novel stimulus their muscle simply grow like crazy, no matter how short your study period, how flawed your exercise program or how useless your supplement may be - and that, in turn, reduces your costs and the threat of observing a null-result dramatically. You better keep these general objections in mind, especially if you look at absolute values of studies like this one.

Figure 1: Relative increase in biceps cross sectional area [CSA] of 3 sets a 10 reps (3x10) and 10 sets a 3 reps (10x3) compared to 20 sets of 3 reps (data calculated based on Chan. 2011)

With the afore-made objections in mind, the relative results depicted in figure 1, do still provide some insight into the differential time-course of the effects of a high intensity training with 10 sets a 3 reps (10x3) and a classic hypertrophy regimen with 3 sets a 10 reps. The greater increase in muscle CSA on the first day (both are expressed relative to the 20x3 regimen that both group A and group B performed) in what I would like to call the hypertrophy group (3x10), as well as the delayed response in the high intensity 10x3 group appear to support the commonly cited hypothesis that due to the greater myofibrilar damage the high intensity 10x3 protocol would inflict, it takes longer for the muscles to recover and thus grow.

Figure 2: Relative elevation of creatine kinase over baseline in group A (3x10 vs. 20x3) and group B (10x3 vs. 20x3) 4 days after eccentric biceps training (data calculated based on Chan. 2011)

The creatine kinase [CK values are generally accepted as markers of muscular damage] values in figure 2 suggest another conclusion, though. While the CK values in what I labeled the hypertrophy group were still +60% elevated over baseline, they had returned to normal (+8%) in the HIT group already. While this would go against the idea that a 10x3 training regimen requires longer recuperation times than a rather hypertrophy oriented regimen of 3x10 sets, these results would obviously warrant longer term studies in well-trained athletes to be of reasonable significance for any bodybuilder or fitness athlete - especially in view of the marginal and statistical non-significant difference in overall strength and size gains I already cited at the beginning of this post.

For the time being you could however try to switch things up for a week or two and see whether and how a rather unorthodox 10x3 regimen impacts your sleeve size, since even if it may not be the "optimal" training regimen, changing the training stimulus from time to time is always a good idea... ah, and if you wake up four days later with an +2inch increase in your biceps size, please let me know ;-)