Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates

Aussieker T, Hilkens L, Holwerda AM, et al. · Medicine and Science in Sports and Exercise

Muscle connective protein synthesis did not differ between the three arms over 5 h: 0.072 %/h on whey, 0.068 on collagen, 0.058 on placebo, p = 0.09 across the groups. On myofibrillar synthesis, the muscle-protein endpoint, whey did beat placebo (0.041 against 0.032 %/h, p < 0.05) and collagen did not (0.036). The amino acids arrived as expected — collagen raised plasma glycine and proline more than whey, whey raised leucine and essential amino acids more — so collagen was absorbed and still moved neither endpoint. A direct null against the idea that ingested collagen acutely drives connective-tissue synthesis, at least in muscle.

Population

Recreational athletes (30 male, 15 female), single resistance-exercise session, double-blind parallel groups

Intervention

30 g collagen protein after a single resistance-exercise session; biopsies over 5 h with stable-isotope tracers

Comparator

30 g whey protein, and a non-caloric placebo — three parallel arms of fifteen

Limitations

Acute 5-h window only; muscle connective tissue, not cartilage or ligament; post-exercise rather than pre-exercise timing (the Baar protocol doses before exercise). Fifteen young recreational athletes per arm. The senior author's laboratory declares research funding from collagen producers including Gelita and PB Leiner.