Evidence map›Paper›PMID 29945625›Full record

Trial reportJournal of the International Society of Sports Nutrition2018

Eight weeks of resistance training in conjunction with glutathione and L-Citrulline supplementation increases lean mass and has no adverse effects on blood clinical safety markers in resistance-trained males.

Paul Hwang, Flor E Morales Marroquín, Josh Gann, Tom Andre, Sarah McKinley-Barnard, Caelin Kim, Masahiko Morita, Darryn S Willoughby

Open access · goldAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Journal of the International Society of Sports Nutrition, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
17citing papers in PubMed, 2 pooled it
1.6field-weighted citation impact, top 18% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

17 citing papers in PubMed, 2 syntheses or guidelines pooled it, 29 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 6 institutions in 3 countries.

Paul HwangExercise and Biochemical Nutritional Lab, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA.
Flor E Morales MarroquínExercise and Biochemical Nutritional Lab, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA.
Josh GannDepartment of Kinesiology, University of Louisiana Monroe, Monroe, LA, USA.
Tom AndreDepartment of Health, Exercise Science, and Recreation Management, University of Mississippi, University, MS, USA.
Sarah McKinley-BarnardDepartment of Health and Kinesiology, University of South Alabama, Mobile, AL, USA.
Caelin KimExercise and Biochemical Nutritional Lab, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA.
Masahiko MoritaFunction Research Group, Healthcare Products Development Center, Kyowa Hakko Bio Co., Ltd., 2, Miyukigaoka, Tsukuba, Ibaraki, Japan.
Darryn S WilloughbyExercise and Biochemical Nutritional Lab, Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA. darryn_willoughby@baylor.edu.
Baylor University · USNutrition Sciences (Belgium) · BEKyowa Kirin (Japan) · JPUniversity of Louisiana at Monroe · USUniversity of Mississippi · USUniversity of South Alabama · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundSupplementation of combined glutathione (GSH) with L-citrulline in response to a single bout of resistance exercise has been shown to increase plasma nitric oxide metabolites, nitrite and nitrate and cyclic guanosine monophosphate (cGMP), which may play a role in muscle protein synthesis. As a result, in response to resistance training (RT) these responses may establish a role for GSH + L-citrulline to increase muscle mass. This study attempted to determine the effects of an 8-week RT program in conjunction with GSH (Setria®) + L-citrulline, L-citrulline-malate, or placebo supplementation on lean mass and its association with muscle strength. The secondary purpose was to assess the safety of such supplementation protocol by assessing clinical chemistry markers.

methodsIn a randomized, double-blind, placebo-controlled design, 75 resistance-trained males were randomly assigned to ingest GSH + L-citrulline (GSH + CIT), L-citrulline-malate, or cellulose placebo daily while also participating in 8 weeks of RT. The full dose of each supplement was delivered in capsules that were identical in weight, size, shape, and color. Participants completed testing sessions for body composition and muscle strength before and after 4 and 8 weeks of RT and supplementation. Venous blood samples were obtained before and after 8 weeks.

resultsLeg press was increased with RT but was not significantly different between groups (p > 0.05); however, bench press strength was not increased with RT (p > 0.05). There were no significant changes in total body mass, fat mass, or total body water during 8 weeks of RT and supplementation. Lean mass increased in both GSH + CIT when compared to PLC; however, the increase was significant only after 4 weeks. Lean mass and strength were positively correlated (p < 0.05) in GSH + CIT, but not CIT-malate or PLC. Neither RT nor supplementation had any significant effects on blood clinical chemistry variables (p > 0.05).

conclusionCompared to PLC, supplementation of GSH + CIT during resistance training increased lean mass after 4 weeks of RT and was positively associated with muscle strength. However, after 8 weeks of RT there were no significant differences in any of the measured variables.

Indexed as

Dietary SupplementsResistance TrainingAdultBiomarkersBody CompositionCitrullineDietDouble-Blind MethodGlutathioneHumansMalatesMaleMuscle StrengthSports Nutritional Physiological PhenomenaYoung AdultBiomarkersCitrullinecitrulline malateGlutathioneMalatesBody compositionGlutathioneL-citrullineMuscle strengthResistance training

Identifiers

PMID29945625
PMCPMC6020314
OpenAlexW2811510534

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.