Taking L-citrulline or L-arginine supplements for 8 days doesn’t help trained swimmers and triathletes feel less burned out or reduce the buildup of lactic acid in their blood during short, intense freestyle races.

In trained swimmers and triathletes, compare blood lactate levels during standardized 100-m and 200-m freestyle time trials after 8 days of 8 g/day L-citrulline, 8 g/day L-arginine, and placebo, with washout periods between conditions, measuring lactate immediately post-exercise.

Compare blood lactate accumulation during 100-m and 200-m freestyle swimming between two groups of trained swimmers and triathletes: one receiving 8 g/day L-citrulline + L-arginine and the other placebo for 8 days.

Measure changes in blood lactate during 100-m and 200-m freestyle swimming before and after 8 days of 8 g/day L-citrulline or L-arginine supplementation in the same trained athletes.

Observe blood lactate levels during 100-m and 200-m freestyle swimming before and after 8 days of 8 g/day L-citrulline or L-arginine supplementation in a group of trained swimmers and triathletes without randomization or blinding.

Describe blood lactate responses during 100-m and 200-m freestyle swimming after 8 days of 8 g/day L-citrulline or L-arginine in a small group of trained athletes without a control group.