The Effects of a Multicomponent Sleep & Recovery Supplement on Muscle Fatigue and Sleep

The goal of this clinical trial (randomised crossover study) is to learn if a multi-component sleep and exercise recovery supplement can improve sleep quality and enhance recovery following exercise in healthy, recreationally active adults aged 18-40. The main questions it aims to answer are: 1. Does the supplement reduce delayed onset muscle soreness (DOMS) following an intense exercise protocol? 2. Does the supplement improve sleep quality? Researchers will compare the supplement to a placebo (a look-alike tablet with no active ingredients) to see if the supplement improves exercise recovery and sleep quality. In this crossover design, all participants will receive both the supplement and the placebo in separate 2-week periods, with a 2-week washout period in between. Participants will: * Take the supplement during one 2-week period and the placebo during another (order randomised), 30 minutes before bed each day * Complete an exercise protocol involving repeated leg extensions designed to induce muscle fatigue * Attend six laboratory visits, including baseline testing and follow-up assessments at 24 and 48 hours post-exercise * Complete daily sleep questionnaires during each supplementation period * Record food intake prior to exercise trials and replicate it for consistency * Perform muscle soreness assessments and single-leg jump tests before and after exercise, and during recovery