The effect of intact vs hydrolysed collagen on recovery from exercise induced muscle damage: A double-blind, randomised, placebo-controlled trial

<h2>ABSTRACT</h2> Collagen supplementation has the potential to aid in the recovery from exercise-induced muscle damage (EIMD). A novel collagen supplement, rich in intact type I collagen (Natiiv™, Trinsic Collagen Limited), potentially increases delivery of its constituent amino acids and intact alpha helices to the extracellular matrix (ECM) for remodelling. Thirty-six healthy, young and active adults (M=27, age: 21.3 ± 4.3 years, body mass index; 25.2 ± 5.7 kg·m⁻²) were assigned (1:1:1) in a double-blind, randomised, placebo-controlled trial, to consume either: Natiiv™ collagen (0.255 g·day⁻¹ of Natiiv™ collagen), hydrolysed collagen (20 g·day⁻¹ of collagen; Peptan®, Rousselot, Belgium), or placebo (collagen depleted alkaline water; Natiiv™), for 30-days. On day-28, muscle damage-inducing exercise (150 drop jumps) was undertaken. Exercise performance (counter movement, squat, and drop jumps), quadriceps strength (maximal voluntary isometric contraction; leg pain (visual analogue scale, pain pressure threshold, short recovery and stress scale questionnaire); and knee inflammation (via colour fraction ultrasonography) and systemic inflammation (IL-6, IL-10, TNFα); ECM damage (hydroxyproline) and; bone turnover (β-CTX and P1NP) were assessed at baseline, 2.5-h, 24-h, 48-h and 72-h following EIMD. Thirty days of Natiiv™ collagen supplementation had no significant effect on any outcome measure (<i>P</i>>0.05 with small-medium effect sizes) compared to hydrolysed collagen or placebo. Future studies should explore the potential efficacy of Natiiv™ collagen supplementation in other relevant populations/scenarios and assess the post-prandial bioavailability of Natiiv™ collagen and, if impaired, explore interventions that can increase its bioavailability and optimise recovery from EIMD.