Ingestion of a Whey Plus Collagen Protein Blend Increases Myofibrillar and Muscle Connective Protein Synthesis Rates

Abstract

Purpose: Ingestion of whey protein increases myofibrillar but not muscle connective protein synthesis rates. Recently, we defined a whey and collagen protein blend (5:1 ratio) to optimize post-prandial plasma amino acid availability. Here, we assessed the ability of this blend to increase myofibrillar and muscle connective protein synthesis rates at rest and during early recovery from exercise.

Methods: In a randomized, double-blind, parallel design, 28 men (age: 25 ± 5 yr; body mass index: 23.6 ± 2.3 kg·m -2 ) were randomly allocated to ingest either 30 g of protein (25 g whey/5 g collagen; BLEND, n = 14) or a noncaloric placebo (PLA, n = 14) following a single session of unilateral leg resistance-type exercise. Participants received primed continuous l -[ ring - 13 C 6 ]-phenylalanine infusions with blood and muscle biopsy samples collection for 5 h post-prandially to assess myofibrillar and muscle connective protein synthesis rates.

Results: Protein ingestion strongly increased plasma amino acid concentrations, including plasma leucine and glycine concentrations ( P < 0.001), with no changes following placebo ingestion ( P > 0.05). Post-prandial myofibrillar and muscle connective protein synthesis rates were higher in the exercised compared with the rested leg ( P < 0.001). In addition, myofibrillar protein synthesis rates were higher in BLEND compared with PLA in both the rested (0.038 ± 0.008 and 0.031 ± 0.006%·h -1 , respectively; P < 0.05) and exercised (0.052 ± 0.011 and 0.039 ± 0.009%·h -1 , respectively; P < 0.01) leg. Muscle connective protein synthesis rates were higher in BLEND compared with PLA in the rested (0.062 ± 0.013 and 0.051 ± 0.010%·h -1 , respectively; P < 0.05), but not the exercised (0.090 ± 0.021 and 0.079 ± 0.016%·h -1 , respectively; P = 0.11) leg.

Conclusions: Ingestion of a whey (25 g) plus collagen (5 g) protein blend increases both myofibrillar and muscle connective protein synthesis rates at rest and further increases myofibrillar but not muscle connective protein synthesis rates during recovery from exercise in recreationally active, young men.

Trial registration: ClinicalTrials.gov NCT05386771.

FIGURE 1

Plasma glucose (A) and insulin (B) concentrations following test drink ingestion during recovery from a single bout of unilateral leg resistance exercise (t = 0–300 min). The dotted line represents the ingestion of the test drink. Values represent means ± SD; n = 14 per group. Data were analyzed by two-factor repeated-measures ANOVA. Bonferroni post hoc testing was used to detect differences between groups. *Significant treatment difference within the time point, P < 0.05. BLEND, 25 g whey plus 5 g collagen protein; PLA, placebo (water).

FIGURE 2

Heat map of fold changes in plasma amino acid concentrations during the experimental test day after the test drink ingestion during recovery from a single bout of unilateral leg resistance exercise. BCAA, branched-chain amino acids; BLEND, 25 g whey plus 5 g collagen protein (n = 14); EAA, essential amino acids; NEAA, non-essential amino acids; PLA, placebo (water) (n = 14); TAA, total amino acids. For hydroxyproline and hydroxylysine, values under the detection limit were set to 0. Values of t = 0 were set to 1.

FIGURE 3

Post-prandial plasma amino acid concentrations following whey plus collagen protein or placebo ingestion during recovery from a single bout of unilateral leg resistance exercise (t = 0–300 min). Data are displayed for EAA (A), NEAA (B), leucine (C), glycine (D), and proline (E). The dotted line within the graphs represents the ingestion of the test drink. Values represent means ± SD; n = 14 per group. Data for plasma amino acid concentrations were analyzed by a two-factor repeated-measures ANOVA. Bonferroni post hoc testing was used to detect differences between groups. *Significant treatment difference within the time point, P < 0.05. BLEND, 25 g whey plus 5 g collagen protein; PLA, placebo (water). EAA, essential amino acids; NEAA, non-essential amino acids.

FIGURE 4

Post-prandial plasma hydroxyproline and hydroxylysine concentrations following whey plus collagen protein or placebo ingestion as a proxy for collagen protein digestion and amino acid absorption (t = 0–300 min). Data are displayed for hydroxyproline (A) and hydroxylysine (B). The dotted line within the graphs represents the ingestion of the test drink. Values represent means ± SD; n = 14 per group. Data for plasma amino acid concentrations were analyzed by a two-factor repeated-measures ANOVA. Bonferroni post hoc testing was used to detect differences between groups. *Significant treatment difference within the time point, P < 0.05. BLEND, 25 g whey plus 5 g collagen protein; PLA, placebo (water).

FIGURE 5

Plasma l-[ring-¹³C₆]-phenylalanine enrichments (MPE) before (t = −180 to 0 min) and after whey plus collagen protein or placebo ingestion during recovery from a single bout of unilateral leg resistance exercise (t = 0–300 min). The dotted line represents the ingestion of the test drink. Values represent means ± SD; n = 14 per group. Data were analyzed by a two-factor repeated-measures ANOVA. Bonferroni post hoc testing was used to detect differences between groups. *Significant treatment difference within the time point, P < 0.05. BLEND, 25 g whey plus 5 g collagen protein; PLA, placebo (water).

FIGURE 6

Fractional myofibrillar protein synthesis rates (%^.h⁻¹) during the post-absorptive period (basal; t = −180 to 0 min), after whey plus collagen protein or placebo ingestion in rest and during recovery from a single bout of unilateral leg resistance exercise (t = 0–300 min). Bars represent means and circles represent individual values; n = 14 per group. Data within one condition have been analyzed by independent-samples t-tests. Time-course data were analyzed by a two-factor repeated-measures ANOVA. Bonferroni post hoc testing was used to detect differences between groups. *Significant treatment difference within the condition, P < 0.05. #Significant difference compared with the basal condition, P < 0.05. $Significant difference compared with the rested condition, P < 0.05. BLEND, 25 g whey plus 5 g collagen protein; PLA, placebo (water).

FIGURE 7

Fractional muscle connective protein synthesis rates (%^.h⁻¹) during the post-absorptive period (basal; t = −180 to 0 min), after whey plus collagen protein or placebo ingestion in rest and during recovery from a single bout of unilateral leg resistance exercise (t = 0–300 min). Bars represent means, and circles represent individual values; n = 14 per group. Data within one condition have been analyzed by independent-samples t-tests. Time-course data were analyzed by a two-factor repeated-measures ANOVA. Bonferroni post hoc testing was used to detect differences between groups. *Significant treatment difference within the condition, P < 0.05. #Significant difference compared with the basal condition, P < 0.05. $Significant difference compared with the rested condition, P < 0.05. BLEND, 25 g whey plus 5 g collagen protein; PLA, placebo (water).