Impact of gelatin supplementation on indices of skeletal muscle recovery: a pilot study.

purposeThis pilot study examined whether collagen supplementation, via gelatin, influences indices of skeletal muscle recovery following strenuous exercise.

methodsUsing a double-blind, randomized, placebo-controlled design, recreationally-active adults (25.9 ± 4.6 yrs.; 11 F, 11 M) consumed gelatin (GEL; 15 g) or placebo (PLA) twice daily. Participants performed 150 maximal unilateral eccentric knee extensions. Muscle soreness (MS), assessed passively and dynamically (concentric, eccentric), peak isokinetic (PKT180, PKT60) and isometric torque (PMT), muscle morphology, and serum hydroxyproline (HYP) and procollagen-1 N-terminal peptide (P1NP) were assessed prior to- (Pre), 24 h, 72 h, and 168 h post-exercise. REPORTS: Exercise significantly increased soreness and impaired function over time (soreness: partial-eta-squared=0.56-0.76; torque: partial-eta-squared=0.34-0.61; all P<0.001), while group and group by time effects were not significant for these outcomes (P>0.05). Exploratory, pairwise comparisons suggested lower MS in GEL at select timepoints, including lower concentric MS at 24 h (P=0.029, d=0.97) and lower passive MS at 168 h (P = 0.028, d = 0.99). Differences in contractile function between groups were not statistically significant, though exploratory estimates favored GEL at 72 h for PKT60 (P = 0.067, d = 0.80) and PMT (P = 0.066, d = 0.81). HYP increased over time (partial-eta-squared=0.47, P<0.001) without group differences, and P1NP did not change over time or differ by group (P>0.05).

conclusionGEL was associated with moderate-to-large time-specific effect estimates suggesting lower soreness and potentially improved force recovery at select timepoints; however, no significant group by time interactions were detected. These findings should be interpreted as preliminary and hypothesis-generating, supporting future trials into the effects of GEL as a recovery modality.