The Effect of Whey Protein Supplementation with and Without Creatine Monohydrate Combined with Resistance Training on Lean Tissue Mass and Muscle Strength

Abstract

Our purpose was to assess muscular adaptations during 6 weeks of resistance training in 36 males randomly assigned to supplementation with whey protein (W; 1.2 g/kg/day), whey protein and creatine monohydrate (WC; 0.1 g/kg/day), or placebo (P; 1.2 g/kg/day maltodextrin). Measures included lean tissue mass by dual energy x-ray absorptiometry, bench press and squat strength (1-repetition maximum), and knee extension/flexion peak torque. Lean tissue mass increased to a greater extent with training in WC compared to the other groups, and in the W compared to the P group (p < .05). Bench press strength increased to a greater extent for WC compared to W and P (p < .05). Knee extension peak torque increased with training for WC and W (p < .05), but not for P. All other measures increased to a similar extent across groups. Continued training without supplementation for an additional 6 weeks resulted in maintenance of strength and lean tissue mass in all groups. Males that supplemented with whey protein while resistance training demonstrated greater improvement in knee extension peak torque and lean tissue mass than males engaged in training alone. Males that supplemented with a combination of whey protein and creatine had greater increases in lean tissue mass and bench press than those who supplemented with only whey protein or placebo. However, not all strength measures were improved with supplementation, since subjects who supplemented with creatine and/or whey protein had similar increases in squat strength and knee flexion peak torque compared to subjects who received placebo.

Effects of Whey Protein Alone or as Part of a Multi-ingredient Formulation on Strength, Fat-Free Mass, or Lean Body Mass in Resistance-Trained Individuals: A Meta-analysis

“…Studies using whey protein and WP-MTN including creatine were differentiated because the combination of whey protein with creatine [27,28], in addition to other protein sources (casein; soy, colostrum), and/or enriched with amino acids [16] would affect body composition [28] and muscle strength [29] in resistance trained individuals, and thus a differential effect from different whey protein combinations would be expected. Therefore, studies were classified into two distinct groups, as a moderator: 1) whey protein alone, or combined with small amounts (less than 20% of the total) of other protein sources or amino acids including no creatine, and 2) whey protein administered as a part of a multi-ingredient (no more than 80% of the total) combined with other protein sources, amino acid, or derivatives, including creatine (WP-MTN).…”

“…The remaining 34 publications were fully read and carefully examined by two reviewers. After this examination, 25 were excluded and therefore, a total of 9 studies [14,27,31,2,28,12,17,29,18] were included in the meta-analysis. …”

“…Resistance training interventions ranged from a minimum of 6 to a maximum of 12 weeks. Differences in population included recreational resistance training individuals in 7 studies with one [14,12,16,18], two [31], or three years [27,29] of regular resistance training experience. In addition, another two studies included recreational body builders [2,28] with a minimum of two years of experience.…”

“…An isocaloric carbohydrates beverage was the contrast supplement in 6 studies [27,31,28,16,29,18]. In the study by Brown et al [14] protein bars were considered to compare whey versus soy protein effects.…”

“…Cribb et al [28] also compared the effects of a WP-MTN administered through a loading phase (week 1) that contained 83 g of protein, <4.8 g of carbohydrate, <1 g of fat, 24 g of creatine monohydrate, followed by a maintenance phase supplement (weeks 2-11) that provide 96 g of protein, <5.5 g of carbohydrate, <1 g of fat, 8.4 g of creatine monohydrate per day. Burke et al [27] analyzed the effects of two treatment conditions, whey protein alone and a WP-MTN including 1.2 g of protein and 0.1 g of creatine monohydrate per kg/d mixed with others vitamins and nitrogenous containing compounds such as inositol arginine and N-acetylcysteine. Kerksick et al [16] were the only researchers who evaluated two treatment conditions; whey protein mixed with small amount of casein (8 g; 20%) and BCAA (5 g; 12.5%) and L-glutamine (3 g; 7.5%).…”