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Cited by 10Hormonal and reproductive studiesHypothalamic control of reproductive hormonesSports Performance and Training

Short-Term d-Aspartic Acid Supplementation Does Not Affect Serum Biomarkers Associated With the Hypothalamic–Pituitary–Gonadal Axis in Male Climbers

Crewther, Blair, Witek, Konrad, Draga, Paweł, Zmijewski, Piotr, Obmiński, Zbigniew·2019·International Journal of Sport Nutrition and Exercise Metabolism
DOI 10.1123/ijsnem.2018-0076
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Abstract

D-aspartic acid (DAA) is promoted as a testosterone (T) enhancing supplement by mechanisms involving the hypothalamic–pituitary–gonadal (HPG) axis. Here, we investigated the short-term effects of DAA on serum biomarkers of the HPG-axis in male climbers. Using a single-blinded, placebo-controlled design, 16 climbers were randomly assigned to either a DAA (3 g/day) or placebo (3 g/day) supplement for 2 weeks. The reverse treatment commenced after a 2-week washout, with all conditions administered in a balanced manner. The subjects maintained their normal weekly training across this study. Serum samples taken before and after each treatment were analyzed for T, luteinizing hormone, sex hormone binding globulin, and cortisol (C), and free T was calculated (cFT). The DAA supplement did not significantly affect serum T, cFT, and luteinizing hormone levels. Only a main effect of time on sex hormone binding globulin (6.8% increase) and C (13.6% decrease) emerged (p < .03). Significant negative associations were identified between pretest values and changes (%) in T, cFT, luteinizing hormone, and C levels with DAA and/or placebo, but these relationships did not differ between treatments (p > .46). Additional measures of physical function and serum hematology also failed to respond to DAA. In summary, a daily dose of DAA during a short training period did not influence T and selected indicators of the HPG-axis in male climbers. Other parameters linked to athletic performance and health status were also unaffected. Our findings support evidence showing that DAA (including DAA-blended supplements) at either recommended or higher dosages does not afford any ergogenic benefits for athletic males.

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  • Crewther et al. found that 2-week D-aspartic acid supplementation at 3 g daily in 16 climbers produced no significant change in testosterone levels or ergogenic benefits in exercise performance.

    “Crewther et al. conducted only on 16 climbers (aged 35.4 ± 7.3 years) who received DAA at a dose of 3 g daily for 2 weeks; no significant change was observed in testosterone levels or ergogenic benefits in exercise performance.[Citation29]”

    From Ergogenic properties, safety evaluation and regulations of selected ingredients in testosterone booster dietary supplements (2024) · cites this paper as [29]

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Authors
Crewther, B., Witek, K., Draga, P., Zmijewski, P., & Obmiński, Z.
Affiliations
  • National Research Institute (US)
  • Institute of Sport—National Research Institute
Corresponding author
Crewther, Blair
ORCID
Venue
International Journal of Sport Nutrition and Exercise Metabolism
Publisher
Human Kinetics
Published
2019-05-01
Volume
29
Issue
3
Pages
259-264
ISSN
  • 1526-484X (ISSN-L)
  • 1543-2742
DOI
10.1123/ijsnem.2018-0076
OpenAlex
W2807852416
Cited by
10
References
20
Citations by year
2024: 1 · 2023: 3 · 2022: 2 · 2021: 1 · 2020: 1 · 2019: 1 · 2018: 1
FWCI
0.80
Type
journal article
Language
en
Open access
closed
Locations
  • International Journal of Sport Nutrition and Exercise Metabolism (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Reproductive Medicine › Hypothalamic control of reproductive hormones
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
Keywords
D-aspartic acid, testosterone, hypothalamic-pituitary-gonadal axis, luteinizing hormone, sex hormone-binding globulin, cortisol, free testosterone, dietary supplements, ergogenic aids, physical function
MeSH terms
Adult, Humans, Hydrocortisone, Hypothalamo-Hypophyseal System, Luteinizing Hormone, Male, Mountaineering, Pituitary-Adrenal System, Sex Hormone-Binding Globulin, Testosterone, Biomarkers, Single-Blind Method, Cross-Over Studies, Dietary Supplements, D-Aspartic Acid, Sports Nutritional Physiological Phenomena

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