Effects of Urolithin A Supplementation on Performance and Antioxidant Status in Academy Soccer Players During Preseason: A Pilot Randomised Controlled Trial

Andrea Monsalve Acevedo¹Colin Sanctuary¹Robert John Aitken¹Alex Wilkins¹Natasha Harrison¹Mitchell Naughton^2*

• ¹The University of Newcastle College of Health Medicine and Wellbeing, Callaghan, Australia
• ²The University of Newcastle, Callaghan, Australia

Background: Polyphenol-derived compounds, such as Urolithin A (UA), may exert beneficial effects to performance adaptations during periods of high training stress through several pathways including a reduction in an oxidative stress and improved mitochondrial function. At present, the benefits of UA supplementation have been observed in clinical and preclinical models. This pilot study aimed to investigate the effects of UA supplementation on performance outcomes, antioxidant status, and intervention feasibility and acceptability during a six-week preseason period in academy soccer players. Methods: Twenty male academy soccer players (age: 17.5 ± 1.0 years) were randomly assigned 1:1 to receive 1000 mg/day of UA or an isocaloric taste-matched placebo which was given post-training over the course of a six-week training intervention in a single-blinded, parallel-group design. The intervention was delivered alongside the team's preseason training from November to December 2024. Primary outcome was aerobic endurance (Yo-Yo Intermittent Recovery Test Level 1), with secondary outcomes including lower-limb strength and power (Countermovement Jump), maximal sprinting speed, and salivary antioxidant capacity using the RoXstaTM System. Each of the primary and secondary outcomes were assessed pre and post the intervention. Feasibility and acceptability of the intervention along with dietary intake was assessed via individual questionnaire, pre and post intervention, while subjective stress-recovery status was assessed via questionnaire administered weekly over the duration of the intervention. Primary and secondary data were analysed using linear mixed effects models, with group (UA/placebo) × time (pre/post) interactions interpreted using estimated marginal means. Results: UA supplementation led to significantly greater improvements in Yo-Yo IRT1 performance compared to placebo (Δ = +239 m, 95% CI [20, 454 m], p = 0.048). For secondary outcomes, countermovement jump height also improved in the UA group relative to placebo (Δ = +3.33 cm, [0.88, 5.95 cm], p = 0.020). No group x time differences were observed in sprint speed, jump power, impulse, or duration, or saliva antioxidant assays. Antioxidant activity declined significantly over time in the placebo group but did not so in the UA group. Feasibility and acceptability questionnaire responses indicated the intervention as it was delivered was rated with high feasibility and acceptability.