UCLA Magnesium Formulation Athlete Study

Inclusion Criteria:

* Age 18-35 years.
* Current NCAA Division I athlete at UCLA.
* Actively participating in team training and/or competition.
* Willing to wear a WHOOP 4.0 device continuously during the baseline and treatment periods of the study block.
* Able to swallow oral capsules and follow supplement instructions.
* Able and willing to complete daily REDCap surveys and weekly check-ins during the study block.
* Fluent in English.
* Able to provide informed consent.

Exclusion Criteria:

* Known kidney disease or impaired renal function, assessed by participant-completed screening questions and review by the PI or designated study clinician. Screening asks about known kidney disease, reduced kidney function, dialysis, a history of abnormally high magnesium, and prior medical advice to avoid magnesium supplementation. A positive or uncertain response requires clinician review. If safety cannot be established from the questionnaire and participant interview alone, the athlete will not be enrolled. The study will not access medical records or perform research laboratory testing for this screening.
* Current use of non-study magnesium supplements within the past 30 days or unwillingness to avoid non-study magnesium supplements during the study unless approved by the study clinician.
* Diagnosed or treated sleep disorder likely to confound sleep outcomes, such as untreated or unstable insomnia, sleep apnea, or regular use of sleep medication expected to affect study outcomes.
* Known difficulty swallowing capsules or history of choking.
* Known allergy or sensitivity to magnesium or inactive capsule ingredients.
* Known current pregnancy or breastfeeding, determined by participant self-report; no pregnancy testing is planned for this minimal-risk study. A participant who becomes pregnant or begins breastfeeding during the study will stop study product and notify the study team. Additional exclusionary circumstances include use of magnesium-containing laxatives or antacids during the study unless approved by the study clinician, or significant recent or planned changes in training load, diet, sleep medication, or recovery supplements that the investigator believes would confound interpretation.