Taking arginine supplements for just three days won’t make you stronger or more powerful during short, intense workouts like sprinting or lifting heavy weights—even if you’re already a well-trained athlete.

A study where 20–30 well-trained male athletes receive 6 g/day of arginine or a placebo for 3 days in two separate 4-day periods (with a 7-day washout), with peak and average power output measured via repeated Wingate tests on the final day of each period. Outcomes are compared within each subject across conditions.

A study comparing two matched groups of well-trained male athletes: one group takes 6 g/day arginine for 3 days, the other takes placebo; both groups perform identical intermittent anaerobic exercise tests on day 3, with peak and average power output recorded and compared between groups using independent t-tests.

A study where 15 well-trained male athletes undergo baseline power testing, then take 6 g/day arginine for 3 days, followed by repeat power testing on day 3; change in peak and average power is calculated for each individual and tested for statistical significance using paired t-tests.

A study tracking 100 well-trained male athletes who self-select to take arginine (6 g/day for 3 days) or not, then measuring their power output during standardized intermittent anaerobic tests; comparing mean power output between supplementers and non-supplementers using regression analysis adjusted for training history.

A report describing power output changes in 3–5 well-trained male athletes who took 6 g/day arginine for 3 days and performed anaerobic tests before and after; qualitative or descriptive trends are noted without statistical testing.