L-theanine lowers an archer's anxiety and stress markers in the minutes before competition
1 study · 18 archers measured
The summary today
There is a single study, from 2024: eighteen Korean university women archers, randomly split into two groups of nine, take a daily capsule of L-theanine or a lactose placebo for four weeks and are measured during a national competition at 50 metres. The effect is there but confined to a few minutes. Half an hour before the start the two groups are alike on anxiety, salivary alpha-amylase and cortisol; at twenty minutes alpha-amylase is lower with theanine, 42.7 against 58.3; at ten minutes all three measures are, with anxiety at 6.9 against 8.7 out of ten, alpha-amylase at 81.3 against 102.5 and cortisol at 10.7 against 14.6. Twenty minutes after the end anxiety is identical in the two groups, at 4.56, while cortisol stays lower. With theanine the salivary markers change course over time, while the curve of reported anxiety does not: its difference comes from a single point comparison. On the competition result the author writes that there was no difference, without giving the scores. On top of this come nine people per group, no measurement at the start of the four weeks, randomisation and blinding that are not described, and passages of the text that contradict the table, including cortisol after the competition. It is a pointer on anxiety before shooting, not on performance.
Also phrased as: "theanine before competition"; "supplements for competition anxiety"; "l-theanine and cortisol"; "calming down before shooting"; "green tea theanine"
In practice
Among competition supplements, L-theanine circulates as the way to stay calm without slowing down, taken in the days before or on the morning of the event.
Evidence
-
2024
For Archers Published later
18 Korean university women archers, 9 on L-theanine and 9 on a lactose placebo for four weeks, measured in competition at 50 metres: cognitive anxiety on a 1 to 10 scale ten minutes before the start 6.9 ± 0.8 with theanine against 8.7 ± 0.8 with placebo (p < 0.05); at thirty and twenty minutes no difference (3.2 against 2.8 and 5.2 against 4.8).
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
-
2024
For Archers Published later
With theanine salivary alpha-amylase rises less: twenty minutes before the start 42.7 ± 8.2 against 58.3 ± 9.5 U/mL, at ten minutes 81.3 ± 12.1 against 102.5 ± 18.2 (p < 0.05); group by time interaction F = 4.25.
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
-
2024
For Archers Published later
Salivary cortisol is lower with theanine ten minutes before the start, 10.7 ± 2.6 against 14.6 ± 3.8, and twenty minutes after the competition, 13.5 ± 3.4 against 18.9 ± 4.8 (p < 0.05); group by time interaction F = 12.96. The results text, however, says cortisol after the competition was higher in the theanine group.
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
-
2024
Context Archers Published later
The group by time interaction is significant for alpha-amylase (F = 4.25) and cortisol (F = 12.96), not for anxiety (F = 1.25): theanine changes the course of the salivary markers, not the shape of the reported anxiety curve, and the difference in anxiety comes from a single point comparison.
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
-
2024
Context Archers Published later
Half an hour before the start, placebo against theanine: anxiety 2.8 ± 1.8 and 3.2 ± 1.7 out of 10, alpha-amylase 28.5 and 31.0 U/mL, cortisol 4.5 and 4.8, no difference. It is the only point of comparison before the effect appears, because there is no measurement at the start of the four weeks.
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
-
2024
Context Archers Published later
Twenty minutes after the end, anxiety is 4.56 ± 0.8 in both groups. In the placebo group anxiety triples from thirty to ten minutes before the start, from 2.8 to 8.7.
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
-
2024
Context Archers Published later
On the competition result the author writes that there was no difference between groups, but the scores are not reported.
Effects of supplement L-theanine on cognitive anxiety, salivary alpha-amylase, and cortisol in archery competition · In-Soo Lim
Status history
- 1990 Not studied The registry's bibliography holds no study of L-theanine in archers, nor in other precision sports. The idea that it calms nerves before competition circulates among supplements, but nobody has tested it on people who shoot: not studied.
- 2024 Reported Eighteen Korean university women archers are randomly assigned to a daily capsule of L-theanine or a placebo for four weeks, then measured during a national competition. Thirty minutes before the start the groups are alike; at ten minutes, with theanine, anxiety is 6.9 against 8.7 out of ten, alpha-amylase 81.3 against 102.5 and cortisol 10.7 against 14.6, and twenty minutes after the end anxiety is identical again. The salivary markers change course, the anxiety curve does not, and on scores the author reports no difference without giving the data. One study, nine people per group, with inconsistencies between text and table: reported.
Related
Related articles
- Supplements in archery: what studies have measured on eyesight, anxiety and tremorCarotenoids with omega-3, L-theanine and jatamansi: what studies in archers have measured, and why none has shown a higher score in archers alone.
- Caffeine and alcohol in archery: what the science saysCaffeine, alcohol, beta-blockers and nicotine in archery: what studies in archers have measured, almost always with a single study per substance.
Research lines
Cite
Campagna, M. (2026). L-theanine lowers an archer's anxiety and stress markers in the minutes before competition (Version 2). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/health/l-theanine-competition-anxiety
@misc{campagna2026_teaninaansiagara,
author = {Campagna, Matteo},
title = {L-theanine lowers an archer's anxiety and stress markers in the minutes before competition},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/health/l-theanine-competition-anxiety},
note = {Version 2; accessed 2026-10-16}
}
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