Effects of Whey Isolate, Creatine, and Resistance Training on Muscle Hypertrophy

Abstract

Although WP and/or CrM seem to promote greater strength gains and muscle morphology during RE training, the hypertrophy responses within the groups varied. These differences in skeletal muscle morphology may have important implications for various populations and, therefore, warrant further investigation.

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).…”

“…Furthermore, the study of Cribb et al [28] investigated a four parallel groups randomized design to compare the effects of whey protein only, whey protein mixed with creatine, carbohydrate mixed with creatine, and only carbohydrate, on different outcomes including LBM and maximal strength. From this investigation, we excluded the data of the carbohydrate plus creatine group (Table 1).…”

“…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. …”

“…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. Only Kerksick et al [16] allowed participants to perform a complementary endurance training for no longer than 20 minutes at a time.…”

“…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.…”