The effects of L-Citrulline and Glutathione on Endurance performance in young adult trained males

What Was Tested

Researchers studied Glutathione in this randomized controlled trial publication.

The purpose of this randomized, double-blind, placebo-controlled crossover study was to investigate effects of L-citrulline + Glutathione on aerobic exercise performance and blood flow in well-trained men.

Participants performed a maximal oxygen consumption treadmill test to determine peak velocity (PV) and returned after eight days of ingesting either PL or SPB.

Why It Was Studied

Citrulline may amplify the effects of L-arginine and nitric oxide concentration, which may augment vasodilation and blood flow, thereby enhancing aerobic exercise performance.

Who Took Part

By PubMed's age tags, the people studied were young adults and adults, men only.

After a 14-day washout, participants repeated the same procedures, ingesting the opposite treatment.

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

The participants were allocated by chance, so the Glutathione group and the comparison group should start out alike.

As a double-blind Glutathione study, the assignments were hidden from both participants and investigators until the end.

Some participants received a placebo instead of Glutathione, giving a reference point.

In the crossover set-up each of the participants took both Glutathione and the comparison in turn, acting as their own control.

The timeline in the abstract includes 14 days.

Brachial artery blood flow and vessel diameter were assessed using ultrasound at 1-hr prior to exercise (1hrPrEX), after each exercise bout, immediately post-exercise (immediate PEX), and 30 minutes post exercise (30minPEX) at visits 2 and 4.

Blood analytes were assessed via venous blood draws at visit 1, visit 3, and 1hrPEX, immediate PEX, and 30minPEX at visits 2 and 4.

Separate repeated measures ANOVAs were performed for TTE, vessel diameter, blood flow, and blood analytes.

What Was Measured

The subject headings attached to it are Dietary Supplements, Citrulline, Capsules, Glutathione and Arginine.

The authors tagged it with the keywords Blood flow, critical velocity, running performance and vasodilation.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Glutathione over 14 days.

The abstract goes on to report its results in about 3 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2023 (Journal of the International Society of Sports Nutrition), a journal based in United States.

More context: the Glutathione compound page, all human trials.