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FSR ? more muscle = no news for ya!

For the average SuppVersity reader the sentence "Acute Post-Exercise Myofibrillar Protein Synthesis Is Not Correlated with Resistance Training-Induced Muscle Hypertrophy in Young Men" is not just the title of a recent paper in the open access journal PLOS|ONE, its also the experimental verification of a claim Ive made in almost all my articles about the acute effects of certain training modalities and/or supplements on myofibrillar protein synthesis and the corresponding increases in muscle size some people appear to expect from a 2h-long 10% increase in fractional protein synthesis (learn more).

And yes, practically speaking these findings imply that we have to question the real world significance of all the neat studies on the "superior muscle building effects" of whey protein, BCAAs and even more so leucine, in which the authors base their recommendations on acute increases in post-exercise protein synthesis.
In the corresponding experiment that was funded by the National Science and Engineering Research Council (NSERC) of Canada Cameron J. Mitchell et al. determined whether the acute myofibrillar protein synthesis measured acutely in training-naive subjects after their first bout of resistance exercise with protein consumption would correlate with the actual increase in muscle size after 16 weeks of resistance training.

Suggested read: "Protein Intake & Muscle Catabolism: Fasting Gnaws on Your Muscle Tissue and Abundance Causes Wastefulness " | more

Before the actual experiment began, the subjects, healthy young recreationally active normal-weight men (177 cm; body mass index = 26.4 kg/m²; men age 22 years) without previous strength training experience, underwent a magnetic resonance imagining (MRI) scans of their right thigh to determine muscle volume, a dual, energy x-ray absorptiometry (DXA) scan to assess whole body fat and bone-free mass (lean mass) and standardized strength tests to determine their maximal isotonic strength (often labeled the 1RM) for all training exercises.

After all baseline measurements (including baseline muscle protein synthesis) were recorded, the subjects completed 16 weeks of RT while ingesting a protein rich beverage (30g of the same whey protein of which Burd et al. showed in 2012 that it elicits a higher increase in MPS than casein) immediately after their exercise session and with breakfast on non-training days.

"Briefly, participants trained four times weekly with two upper and two lower body workouts. Lower body exercises are described above in the acute exercise session. Upper body exercises consisted of chest press, shoulder press, seated row, lat pulldown, bicep curl and tricep extension. The program was progressive in linear manner moving from 3 sets of 12 repetitions to 4 sets of 6  repetitions. At the end of the training period, MRI, DXA scans and strength testing were repeated." (Mitchell. 2014)

If you look at the above description of the workout (and supplementation regimen) you will probably agree that this is pretty much what the majority of resistance physique oriented gym-goers do.

Figure 1: Myofibrillar fractional protein synthesis rate (left) measured acutely after a single workout and changes in muscle volume (%) over the whole 16-week study period as a function of the 1-6h post-workout FSR (Mitchell. 2014).

People who hope that the often reported increases in fractional protein synthesis would pay off and yield increased net muscle gains and thus exactly what Mitchell et al. did not observe in their study, which could not establish the corresponding correlation between the actute increase in post-workout fractional protein synthesis (Figure 1, left) and the chronic change in muscle volume (Figure 1, right).

Figure 2: Changes in muscle volume (%) expressed relative to acute increases in 4E-BP (Mitchell. 2014).

If anything, it was the expression of the Eukaryotic translation initiation factor 4E-binding protein 1 aka 4E-BP1 one of the motors of protein synthesis, but not the increase in myofibrillar fractional protein synthesis that looked as if it could have any predictive value with respect to the increase in muscle volume, the young men experienced in the course of the 16-week training period.

After thinking about the implications of these findings for a minute, I do yet have to admit that the assumption that this would refute the previously invoked recommendations completely, is probably premature.
Reference:

• Burd, Nicholas A., et al. "Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men." British Journal of Nutrition 108.06 (2012): 958-962.

Higher reps, dont 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.
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).
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.
References:

• 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