UCLA Magnesium Formulation Athlete Study

This randomized, double-blind, placebo-controlled trial will compare magnesium glycinate, magnesium L-threonate, and placebo in UCLA varsity athletes. Participants will complete a baseline monitoring period followed by 4 weeks of blinded nightly supplementation. WHOOP or study-approved wearable data will be used to evaluate sleep efficiency, total sleep time, sleep consistency, heart rate variability, resting heart rate, and recovery metrics. Baseline and final testing will assess selected reaction and physical performance outcomes. The primary outcome is change in WHOOP-derived sleep efficiency from baseline week to final treatment week.

Inclusion Criteria: * Age 18 to 35 years. * Current UCLA varsity athlete. * Actively training or competing during the study period. * Willing to wear WHOOP or a study-approved wearable device continuously during baseline and treatment periods if wearable data are used. * Willing to take assigned study capsules nightly for 28 days. * Willing to complete brief daily REDCap surveys and weekly adherence/safety check-ins. * Able to provide informed consent and comply with study procedures. Exclusion Criteria: * Current magnesium supplementation without completion of an appropriate washout before baseline. * Current investigational drug or investigational supplement use. * Current use of prescription or over-the-counter sleep medications unless reviewed and permitted by the study clinician. * Diagnosed sleep disorder that, in the investigator's judgment, would confound outcomes or increase risk. * Significant kidney disease or another medical condition that may increase risk with magnesium supplementation. * Known intolerance or allergy to magnesium glycinate, magnesium L-threonate, placebo, or inactive study ingredients. * Use of medications with clinically relevant magnesium interactions unless reviewed and permitted by the study clinician. * Any other condition that, in the investigator's judgment, would make participation unsafe, compromise voluntary consent, or prevent valid outcome assessment.