Effects of Graded Whey Supplementation During Extreme-Volume Resistance Training

Abstract

We examined hypertrophic outcomes of weekly graded whey protein dosing (GWP) vs. whey protein (WP) or maltodextrin (MALTO) dosed once daily during 6 weeks of high-volume resistance training (RT). College-aged resistance-trained males (training age = 5 ± 3 years; mean ± SD) performed 6 weeks of RT wherein frequency was 3 d/week and each session involved 2 upper- and 2 lower-body exercises (10 repetitions/set). Volume increased from 10 sets/exercise (week 1) to 32 sets/exercise (week 6), which is the highest volume investigated in this timeframe. Participants were assigned to WP (25 g/d; n = 10), MALTO (30 g/d; n = 10), or GWP (25–150 g/d from weeks 1–6; n = 11), and supplementation occurred throughout training. Dual-energy x-ray absorptiometry (DXA), vastus lateralis (VL), and biceps brachii ultrasounds for muscle thicknesses, and bioelectrical impedance spectroscopy (BIS) were performed prior to training (PRE) and after weeks 3 (MID) and 6 (POST). VL biopsies were also collected for immunohistochemical staining. The GWP group experienced the greatest PRE to POST reduction in DXA fat mass (FM) (−1.00 kg, p < 0.05), and a robust increase in DXA fat- and bone-free mass [termed lean body mass (LBM) throughout] (+2.93 kg, p < 0.05). However, the MALTO group also experienced a PRE to POST increase in DXA LBM (+2.35 kg, p < 0.05), and the GWP and MALTO groups experienced similar PRE to POST increases in type II muscle fiber cross-sectional area (~+300 μm2). When examining the effects of training on LBM increases (ΔLBM) in all participants combined, PRE to MID (+1.34 kg, p < 0.001) and MID to POST (+0.85 kg, p < 0.001) increases were observed. However, when adjusting ΔLBM for extracellular water (ECW) changes, intending to remove the confounder of edema, a significant increase was observed from PRE to MID (+1.18 kg, p < 0.001) but not MID to POST (+0.25 kg; p = 0.131). Based upon DXA data, GWP supplementation may be a viable strategy to improve body composition during high-volume RT. However, large LBM increases observed in the MALTO group preclude us from suggesting that GWP supplementation is clearly superior in facilitating skeletal muscle hypertrophy. With regard to the implemented RT program, ECW-corrected ΔLBM gains were largely dampened, but still positive, in resistance-trained participants when RT exceeded ~20 sets/exercise/wk.

Muscle fiber hypertrophy in response to 6 weeks of high-volume resistance training in trained young men is largely attributed to sarcoplasmic hypertrophy

“…In the 15 participants experiencing mean FCA increases >320 μm 2 there was practically equal representation of participants from each of the supplement groups (MALTO n=6, WP n=4, GWP n=5) suggesting that results were likely not influenced from nutritional supplementation. Readers are referred to Haun et al [21] for more in-depth descriptions of the supplementation details and nutritional recommendations employed.…”

“…Muscle tissue and blood collection. Muscle biopsies were collected using a 5-gauge needle under local anesthesia as previously described [21]. Immediately following tissue procurement, ~20-40 mg of tissue was embedded in cryomolds containing optimal cutting temperature (OCT) media (Tissue-Tek®, Sakura Finetek Inc; Torrence, CA, USA).…”

“…Methods for cryostat sectioning have been employed previously in our laboratory and described elsewhere [21,22,26,27]. Briefly, sections from OCT-preserved samples were cut at a thickness of 8 μm using a cryotome (Leica Biosystems; Buffalo Grove, IL, USA) and were adhered to positively-charged histology slides.…”

<p>Whey protein supplementation and muscle mass: current perspectives</p>

“…Cribb et al (2006) observed higher lean mass improvements in recreational bodybuilders who were ingesting >1.6 g/kg of protein (estimated by a 3-day diet record analysis) and further supplemented their diet with the addition of 1.5 g/kg/d of WPH isolate vs the same amount of casein over a 10-week intervention period. 61 Conversely, a more recent study 56 reported similar gains in lean mass over a 6-week resistance training intervention combined with the ingestion of 1) 25 g of whey 2) incremental whey protein ingestion protocol from 25 to 150 g/d from weeks 1 to 6; or (iii) 30 g of maltodextrin. All participants, regardless of the group, consumed >2.0 g/kg/d of dietary protein.…”

“…In this regard, the impact of the workout configuration, particularly the volume 54 and the amount of exercised muscle mass 55 has shown to be crucial in altering the dynamics of the MPS response to protein feeding during the post-exercise time. 56 Witard et al 40 reported optimal MPS responses measured over~4 hrs after performing eight sets of ten repetitions of two unilateral lower body exercises and ingesting 20 g of WPI containing~10 g of IAA and~2.2 g of leucine. It is worth highlighting that a dose of 40 g providing~20 g of IAA and 4.4 g of leucine resulted in negligible, non-significant stimulation of MPS.…”