Effects of Oral L-Arginine on Everyday Persistent Fatigue, Sleep, and Post-Exercise Lactate Recovery in Community-Dwelling Working-Age Adults: A Double-Blind, Placebo-Controlled Randomized Trial
5 affiliations
- 1Department of Sports Health Rehabilitation, Daejeon University, Daejeon 34520, Republic of Korea
- 2Department of Sports Data Analysis, Songwon University, Gwangju 61756, Republic of Korea
- 3Department of Korean Medicine, Daegu Haany University, Daegu 42158, Republic of Korea
- 4Integrative Medicine Innovation Center, Wonkwang University, Iksan 54538, Republic of Korea
- 5College of Korean Medicine, Wonkwang University, Iksan 54538, Republic of Korea
Abstract
Background/Objectives: The evidence for nutritional interventions against fatigue is limited; we evaluated whether L-arginine reduces fatigue in working-age adults. Methods: In this 8-week randomized, double-blind, placebo-controlled trial, 120 community-dwelling working-age adults aged 30–59 years with persistent fatigue (Fatigue Severity Scale [FSS] total ≥ 27) received oral L-arginine 3 g/day, 6 g/day, or placebo. The primary endpoint was FSS change; secondary endpoints included the Checklist Individual Strength (CIS), Pittsburgh Sleep Quality Index (PSQI), and blood lactate kinetics during a standardized submaximal treadmill run (~70% VO2max, 30 min). Data from 119 participants were analyzed, with Holm adjustment for multiplicity. Results: At Week 8, FSS decreased more with 6 g/day than with placebo (−6.41 vs. −2.23; Holm-adjusted p = 0.024), whereas 3 g/day did not differ from placebo. The 6 g/day CIS improvement did not survive multiplicity adjustment. PSQI scores improved nominally at both doses (3 g/day, p = 0.007; 6 g/day, p = 0.045). With 6 g/day, the total lactate area under the curve (Holm-adjusted p = 0.041) and 15-min recovery lactate (Holm-adjusted p = 0.002) were lower than with the placebo, whereas the resting plasma nitrite did not differ. No serious adverse events occurred. Conclusions: L-arginine supplementation at 6 g/day for 8 weeks reduced fatigue severity relative to placebo and was well-tolerated; however, mean FSS scores remained above the enrollment threshold, indicating a reduction in, rather than resolution of, persistent fatigue.
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BibTeX
@article{kang2026effects,
title = {{Effects of Oral L-Arginine on Everyday Persistent Fatigue, Sleep, and Post-Exercise Lactate Recovery in Community-Dwelling Working-Age Adults: A Double-Blind, Placebo-Controlled Randomized Trial}},
author = {Eun-Bum Kang and Seong-Bong Hong and Namkyu Yoon and Namju Lee and Byungkwon Kim},
journal = {Nutrients},
year = {2026},
month = oct,
doi = {10.3390/nu18203375},
url = {https://www.mdpi.com/2072-6643/18/20/3375},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Effects of Oral L-Arginine on Everyday Persistent Fatigue, Sleep, and Post-Exercise Lactate Recovery in Community-Dwelling Working-Age Adults: A Double-Blind, Placebo-Controlled Randomized Trial
AU - Eun-Bum Kang
AU - Seong-Bong Hong
AU - Namkyu Yoon
AU - Namju Lee
AU - Byungkwon Kim
PY - 2026
DA - 2026/10/01
JO - Nutrients
DO - 10.3390/nu18203375
UR - https://www.mdpi.com/2072-6643/18/20/3375
AB - Background/Objectives: The evidence for nutritional interventions against fatigue is limited; we evaluated whether L-arginine reduces fatigue in working-age adults. Methods: In this 8-week randomized, double-blind, placebo-controlled trial, 120 community-dwelling working-age adults aged 30–59 years with persistent fatigue (Fatigue Severity Scale [FSS] total ≥ 27) received oral L-arginine 3 g/day, 6 g/day, or placebo. The primary endpoint was FSS change; secondary endpoints included the Checklist Individual Strength (CIS), Pittsburgh Sleep Quality Index (PSQI), and blood lactate kinetics during a standardized submaximal treadmill run (~70% VO2max, 30 min). Data from 119 participants were analyzed, with Holm adjustment for multiplicity. Results: At Week 8, FSS decreased more with 6 g/day than with placebo (−6.41 vs. −2.23; Holm-adjusted p = 0.024), whereas 3 g/day did not differ from placebo. The 6 g/day CIS improvement did not survive multiplicity adjustment. PSQI scores improved nominally at both doses (3 g/day, p = 0.007; 6 g/day, p = 0.045). With 6 g/day, the total lactate area under the curve (Holm-adjusted p = 0.041) and 15-min recovery lactate (Holm-adjusted p = 0.002) were lower than with the placebo, whereas the resting plasma nitrite did not differ. No serious adverse events occurred. Conclusions: L-arginine supplementation at 6 g/day for 8 weeks reduced fatigue severity relative to placebo and was well-tolerated; however, mean FSS scores remained above the enrollment threshold, indicating a reduction in, rather than resolution of, persistent fatigue.
SN - 2072-6643
ER -