The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance training

Abstract

Aim: Bioactive collagen peptides (CP) have been suggested to augment the functional, structural (size and architecture), and contractile adaptations of skeletal muscle to resistance training (RT), but with limited evidence. This study aimed to determine if CP vs. placebo (PLA) supplementation enhanced the functional and underpinning structural, and contractile adaptations after 15 weeks of lower body RT.

Methods: Young healthy males were randomized to consume either 15 g of CP (n = 19) or PLA (n = 20) once every day during a standardized program of progressive knee extensor, knee flexor, and hip extensor RT 3 times/wk. Measurements pre- and post-RT included: knee extensor and flexor isometric strength; quadriceps, hamstrings, and gluteus maximus volume with MRI; evoked twitch contractions, 1RM lifting strength, and architecture (with ultrasound) of the quadriceps.

Results: Percentage changes in maximum strength (isometric or 1RM) did not differ between-groups (0.684 ≤ p ≤ 0.929). Increases in muscle volume were greater (quadriceps 15.2% vs. 10.3%; vastus medialis (VM) 15.6% vs. 9.7%; total muscle volume 15.7% vs. 11.4%; [all] p ≤ 0.032) or tended to be greater (hamstring 16.5% vs. 12.8%; gluteus maximus 16.6% vs. 12.9%; 0.089 ≤ p ≤ 0.091) for CP vs. PLA. There were also greater increases in twitch peak torque (22.3% vs. 12.3%; p = 0.038) and angle of pennation of the VM (16.8% vs. 5.8%, p = 0.046), but not other muscles, for CP vs. PLA.

Conclusions: CP supplementation produced a cluster of consistent effects indicating greater skeletal muscle remodeling with RT compared to PLA. Notably, CP supplementation amplified the quadriceps and total muscle volume increases induced by RT.

Keywords: Magnetic resonance imaging; Muscle volume; Quadriceps femoris; Supplementation.

FIGURE 1

Pre to post percentage changes (Δ) in knee extension isometric maximum voluntary torque (MVT; A), knee extension one‐repetition maximum (1RM; B), and knee flexion MVT (C) after 15 weeks of lower‐body resistance training, with collagen peptide (CP, n = 19) or placebo (PLA, n = 20) supplementation. Data are mean ± SD with plots displaying individual participant data. No significant between‐group differences were detected from percentage change data (unpaired t‐test: 0.703 ≤ p ≤ 0.929) for MVT or 1RM.

FIGURE 2

Pre to post absolute changes (Δ) in knee extension isometric explosive strength ([A] absolute torque and [B] torque expressed relative to maximum voluntary torque [MVT]) at 50 ms intervals after torque onset, after 15 weeks of lower‐body resistance training, with collagen peptide (CP, n = 19) or placebo (PLA, n = 20) Supplementation. Data are mean ± SD with plots displaying individual participant data. No significant between‐group differences occurred for absolute torque (ANOVA group × time: 0.054 ≤ p ≤ 0.474) or torque expressed relative to MVT (ANOVA group × time: 0.177 ≤ p ≤ 0.862).

FIGURE 3

Pre to post percentage changes (Δ) in quadriceps (A), hamstrings (B), and gluteus maximus (C) and total muscle (Σ quadriceps, hamstrings, and gluteus maximus; (D) volume after 15 weeks of lower‐body resistance training, with collagen peptide (CP, n = 19) or placebo (PLA, n = 20) supplementation. Data are mean ± SD with plots displaying individual participant data. Unpaired t‐test p values are displayed when statistical tendencies (0.05 ≤ p ≤ 0.10) or significant (p < 0.05, denoted by *) differences between‐groups occurred.

FIGURE 4

Pre to post percentage changes (Δ) in knee extension evoked twitch contraction peak torque (A) and time to peak torque (B) after 15 weeks of lower‐body resistance training, with collagen peptide (CP, n = 19) or placebo (PLA, n = 20) supplementation. Data are mean ± SD with plots displaying individual participant data. Unpaired t‐test p values are displayed when statistical tendencies (0.05 ≤ p ≤ 0.10) or significant (p < 0.05, denoted by *) differences between‐groups occurred.