Tuesday, July 15, 2014

Lower Rep Numbers Power Up Strength Gains Without Compromising Hypertrophy: Study Compares Volume-Equated 3x10 vs. 7x3 Resistance Training Regimen

Higher reps, don't prevent muscle gain, ladies (img. fighterdiet.com)
As a SuppVersity reader you know that the number of studies with reliable and above all relevant information about the differential effects of high vs. low rep training is scarce. Compared to the number of studies which deals with question like "Is it better I perform 10x3 or rather only 7x3 reps x sets of bench presses?", their number is still pretty high, though.

With their latest paper in the Journal of Strength and Conditioning Research Brad Schoenfeld et al. actually break ground: A study with trainees with on average 4.2 ± 2.4 years of training experience (range of 1.5 to 10 years) that deals with the aforementioned question whether 3x10 or 7x3 would be the optimal set x rep range for strength and size gains has yet - at least as far as I recall - not been conducted.
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To compare the two loading strategies, the 20 male study participants were randomly assigned to one of the two types of resistance training routines they had to follow for 8 weeks to the figurative "T" in the study (Schoenfeld. 2014):
  • a strength-type resistance training routine (ST)
  • a hypertrophy-type resistance training routine (HT)
To ensure adequate protein intake, the participants were provided with a free protein supplement on training days. The product (Iso100 Hydrolyzed Whey Protein Isolate, Dymatize Nutrition) contained 24g protein and ony 1g carbohydrate and had to be consumed within one hour post-exercise.
Table 2: Overview of the exercise selection and sequence (Schoenfeld. 2014)
The hypertrophy workout was a split routine where multiple exercises were performed for a specific muscle group in a session, with only 1 muscle group trained per session (see Table 1).
Scientifically accurate, but maybe not 100% realistic: Usually you will see trainees train with an overall higher volume, when they are using 3x10 vs. 7x3 routines. As logical and necessary the standardized volume may be - from a practical point of view it's not realistic to equate both arms for volume-load. This does not mean that the results of the study at hand are irrelevant, but it does mean that they don't necessarily reflect the way advanced trainees train.
A moderate number of repetitions (target of 10 repetitions per set within a range of 8-12 repetitions) were performed with rest periods of 90 seconds afforded between sets and exercises. The load was adjusted for each exercise as  needed on successive sets to ensure that subjects achieved momentary muscular exhaustion within the target repetition range.
Figure 1: Pre- vs. post changes (%) in biceps thickness, bench press and squat performance (Schoenfeld. 2014)
As you can see in Figure 1, the total exercise volume which was kept identical to make the two training regimen comparable, the increase in biceps size is another variable that did not differ in-between the groups.

The latter cannot be said of the 1-RM and bench press and most significantly the 1-RM squat performance which (obviously?) benefits from a lower rep range - at least at a fixed volume.
What's special about this study? The subjects are trained individuals, the differences between the two protocols tested are smaller than in previous studies (e.g. 6x4 vs. 3x10 in Chestnut & Docherty. 1999) and the results implicate that >75% of the trainees could be compromising their strength gains by training with too many reps - and why all that? Because bro-science says: 10-12 reps is optimal for hypertrophy and bigger muscles are "sexier" than stronger ones ;-)
Apropos "fixed volume": While it makes sense from a science point of view to compare 7x3 (ST) and 3x10 (HT) regimen at identical volumes, trainees will usually train at a higher volume on 3x10 rep vs. 7x3 rep regimen.

With respect to the advanced strength gains, I am pretty sure that the volume "restriction" (compared to what we'd see in the real world) in the HT group is not the reason that 7x3 is superior to 3x10, when it comes to building muscle. Rather than that, I would be curious to see, whether a higher volume, higher rep regimen with 3x10 would not induce greater gains in muscle size. The fact that it is already on par with the ST regimen - in spite of significantly lower strength increases - would speak in favor of this hypothesis. Without an additional study, though, the corresponding question cannot be answered.
  • Chestnut, James L., and David Docherty. "The effects of 4 and 10 repetition maximum weight-training protocols on neuromuscular adaptations in untrained men." The Journal of Strength & Conditioning Research 13.4 (1999): 353-359.
  • Schoenfeld, B. et al. "Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men." Journal of Strength and Conditioning Research (2014). Publish Ahead of Print