Effects of whey isolate, creatine, and resistance training on muscle hypertrophy.
Level 2 - randomized trial
Individual randomized controlled trial in humans
PubMed 17277594 · doi:10.1249/01.mss.0000247002.32589.ef
What was done
Resistance-trained males were matched for strength and assigned in a double-blind randomized protocol to one of four daily supplementation groups: creatine with carbohydrate (CrCHO), creatine with whey protein (CrWP), whey protein only (WP), or carbohydrate only (CHO; 1.5 g/kg body weight/day). All subjects completed an 11-week structured, supervised resistance training program. Baseline and post-training assessments included 1-repetition maximum (1RM) strength across three exercises, body composition via dual-energy X-ray absorptiometry (DEXA), and vastus lateralis muscle biopsies to determine muscle fiber type cross-sectional area (type I, IIa, IIx), contractile protein accrual, and muscle creatine content.
What was found
The abstract reports no absolute baseline or post-intervention numerical values, group means, or confidence intervals. Supplementation with CrCHO, WP, and CrWP resulted in significantly greater 1RM strength gains across all three exercise assessments and greater muscle hypertrophy compared with CHO (P < 0.05). Up to 76% of the strength improvements in the squat were reported as attributable to hypertrophy of involved muscle, though hypertrophy responses among active groups varied across whole-body lean mass, fiber-specific hypertrophy, and contractile protein content.
Why it matters
This trial demonstrates that supplementing resistance training with whey protein, creatine, or both yields superior gains in strength and multi-level muscle hypertrophy compared to carbohydrate alone in resistance-trained men.
Limits
The abstract omits total sample size, per-group numbers, participant ages, and all raw numerical measurements, effect sizes, and variance estimates. Results from resistance-trained young men cannot be generalized to females, untrained individuals, or older adults.
Cited by
- partial Two studies have demonstrated greater increases in muscle performance and lean body mass when combining creatine with approximately 30 grams of whey protein compared to creatine alone.