Leucine, Whey Concentrate, Hydro Whey or Soy - How do They Affect Beginner's Early Muscle & Strength Gains?

12 weeks of serious resistance training will transform the body of beginners, but it'll do that regardless of whether you supplement with protein or not, doctoral thesis shows.

The headline of today's SuppVersity article summarizes the research question of a recently published doctoral thesis by Christopher Brooks Mobley (Mobley 2017). In that, Mobley started with the hypothesis that "[w]hey protein in combination with resistance training will provide the greatest
anabolic and ergogenic response" - Was he right? Well, without giving away too much, the most appropriate one-word-answer to this question is "No!"

How's that? Well, let's take a look at diet, training, and supplementation and you may be realizing why the only "magic" whey did was to increase the skeletal muscle satellite cell pool (learn more about Whey's effect on satellite cells).
For his doctoral thesis, Mobley recruited seventy-five untrained, college-aged males (mean±SE; age=21±1 yr, body mass=79.2±0.3 kg; exlusion criteria were: engaging in any regular exercise program for at least 6 months prior to study initiation, already consuming a high-protein diet (>2.0 g/kg/d), using anabolic enhancing agents (e.g., anabolic steroids, supplemental protein, creatine monohydrate, or prohormones), or having any medical or orthopedic condition(s) that would hinder them from participating in the study).

Figure 1: Graphical overview of the study design; IMTP, isometric mid-thigh pull (Mobley 2017).

The subjects were randomly assigned to an isocaloric (~200kcal), lipid- (2-4.5g), and organoleptically-matched (=appearance, taste, texture, and packaging were indistinguishable) maltodextrin placebo (PLA, n=15) twice a day [post-workout (training day) or with any meal (non-training day) and pre-bed], or they received the active treatment containing...

• leucine (LEU, n=14), 
• whey protein concentrate, 80% protein (WPC, n=17),
• whey protein hydrolysate,  67% of peptides as <5 kDa in 80% protein (WPH, n=14), or 
• soy protein concentrate, 80% protein (SPC, n=15) group.

At a dosage of that would provide a standardized amount of 2x3g of leucine per serving. And, yes, that means the participants in the leucine group received only 2x3g leucine per day... nothing else.

Participants performed whole-body resistance training three days per week for 12 weeks while consuming supplements twice daily. 

The training protocol followed a daily undulating periodization (DUP) model, with individual workouts being based on free-weighted barbell squats, bench press, deadlifts, and bent-over rows for ...

• 4 sets of 10 repetitions (Monday or Tuesday), 
• 6 sets of 4 repetitions (Wednesday or Thursday), and 
• 5 sets of 6 repetitions (Friday or Sunday). 

All participants were supervised by laboratory personnel for each training session to ensure that proper lifting technique is executed, and training volumes for each session will be recorded. Participants that missed more than 4 of the 36 planned session were not included in the analysis due to lack of training compliance.

Table 1: Overview of the periodization scheme, with intensities, expressed relative to estimated one repetition maximum (calculated per the NSCA’s recommended guidelines, i.e. 3-RM/0.93 | Mobley 2017).

Eventually, Mobley lost 13 participants due to lack of compliance with supplementation or resistance training. Furthermore, one subject in the WPC group had to withdraw from the study due to a musculoskeletal injury sustained during training.

With data from DXA (incl. hydration test), ultrasound assessment and muscle (and fat) biopsies the study provides very comprehensive and reliable data

A brief glimpse at the results of the 4-day food logs, the scientists evaluated to analyze their subjects' diets revealed ...

• no differences in caloric and macronutrient intakes (i.e., total and relative calories, protein, carbohydrates, and fats) did not differ between groups at the beginning of the study. T1 (all ANOVA p-values >0.50),
• increased caloric intakes in all groups specifically in the time after the deload, when the intensity was increased (training sessions T20 to T39) without an effect o supplementation,
• significantly increased daily protein intakes in all groups, with an expectable group x time effect favoring WPC/WPH/SPC in terms of both, total and relative protein intake.

In contrast to the diets, the training sessions did not show significant group effects, with neither, training volume, nor intensity and/or strength gains during the intervention showing inter-group differences (ANOVA, p=0.286 | see Figure 2).

Figure 2: Total volume lifted during the 12-week training intervention (panel a) as well as pre- and post-intervention 3-repetition maximum (RM) squat values (panel b), 3-RM bench press values (panel c), and isometric mid-thigh pull (IMTP) peak force values (panel d); * within-group increase from pre- to post training (p < 0.05 | Mobley 2017).

Against that background, it becomes less surprising that there were no changes in body mass, muscle mass, fat mass, and vastus lateralis muscle thickness between groups.

Figure 3: Changes in body composition variables and vastus lateralis muscle thickness between groups (Mobley 2017).

In fact, Figure 2, which illustrates the strength gains, and Figure 3, which illustrates the size gains, look surprisingly alike. They confirm the efficacy of the workout, but fail to confirm the expected anabolic benefits of (whey) protein... with one exception:

Satellite cells thrive on whey but don't seem to be needed

As already hinted at, the effects of whey protein on satellite cell proliferation is not a "new" result. In fact, SuppVersity readers have known about the pro-myogenic activity of whey ever since July 2014, when I wrote an article titled "Accelerated Satellite (= Muscle Precursor) Cell Proliferation is Yet Another Way for Whey to Promote Muscle Gains" (read it).

Figure 4: Satellite cell and myonuclei number in type II muscle fibers (Mobley 2017).

In view of the lack of downstream effects on the myonuclei number in type II fibers (note: satellite cells are precursors of myonuclei, they provide a pool for both, the formation of new myonuclei and the replacement of damaged ones | learn more and even more), it is yet only mildly surprising that the increased satellite cell activity didn't translate to size or strength gains.
References:

• Hoffman, Jay R., et al. "Effects of protein supplementation on muscular performance and resting hormonal changes in college football players." Journal of sports science & medicine 6.1 (2007): 85.
• Mobley, Christopher. "The Effects Of Leucine Or Different Protein Supplements On Muscle Hypertrophy After 12 Weeks Of Resistance Training In Untrained Men." Dissertation submitted to the Graduate Faculty of Auburn University in partial fulfillment of the Requirements for the Degree of Doctor of Philosophy of Exercise Science (2017).