Amino acids and sport: a true love story?
· Christophe Moinard
Received: 6 February 2018 / Accepted: 17 May 2018
© Springer-Verlag GmbH Austria, part of Springer Nature 2018
Among a plethora of dietary supplements, amino acids are very popular with athletes for several reasons (e.g., to prevent
nutritional deﬁciency, improve muscle function, and decrease muscle damages) whose purpose is to improve performance.
However, it is diﬃcult to get a clear idea of which amino acids have real ergogenic impact. Here, we review and analyze
the clinical studies evaluating speciﬁc amino acids (glutamine, arginine, leucine, etc.) in athletes. Only english-language
clinical studies evaluating a speciﬁc eﬀect of one amino acid were considered. Despite promising results, many studies have
methodological limits or speciﬁc ﬂaws that do not allow deﬁnitive conclusions. To date, only chronic β-alanine supplemen-
tation demonstrated an ergogenic eﬀect in athletes. Much research is still needed to gain evidence-based data before any
other speciﬁc amino acid can be recommended for use in athletes.
Keywords Glutamine · Arginine · β-Alanine · Leucine · Citrulline · Taurine · Athletes
Food supplements are very popular throughout the world,
especially in Europe and the USA. The European Food
Safety Authority (EFSA) deﬁnes ‘food supplements’ as con-
centrated sources of nutrients or other substances with a
nutritional or physiological eﬀect, whose purpose is to sup-
plement the normal diet. Food supplements are marketed ‘in
dose’ form, for example as pills, tablets, capsules or liquids
in measured doses etc. Supplements may be used to correct
nutritional deﬁciencies or maintain an adequate intake of
certain nutrients, while the Food and Drug Administration
(FDA) deﬁnes a ‘dietary supplement’ as a product intended
for ingestion that contains a “dietary ingredient” intended
to add further nutritional value to (supplement) the diet.
[…] Dietary supplements may be found in many forms such
as tablets, capsules, softgels, gelcaps, liquids, or powders.
Some dietary supplements can help ensure that you get an
adequate dietary intake of essential nutrients; others may
help you reduce your risk of disease. These deﬁnitions are
similar in many countries. However, the spectrum of the
dietary supplement market runs from nutritional proper-
ties to physiological properties, and physiological proper-
ties to ergogenic eﬀects (increasing performance directly
or not). Athletes are a focal population (Karimian and Esfa-
hani 2011; Salgado et al. 2014), with a dual interest in tak-
ing dietary supplements to (1) avoid performance-eroding
nutritional deﬁciencies and (2) gain competitiveness (per-
formance, recovery, immunity, etc.).
Among a plethora of dietary supplements, amino acids or
their derivatives are very popular with athletes as they are
thought to have ergogenic eﬀects. Almost all athletes are
convinced that amino acids can help them gain competitive-
ness, and many companies propose amino acids (alone or in
mixture) to help sportsmen. However, the scientiﬁc rationale
for the use of such amino acids is often thin and not neces-
sarily based on good science. In this context, it is diﬃcult
for consumers to separate fact from ﬁction.
The purpose of this review is to provide a critical analysis
of the literature on the potential ergogenic eﬀects of amino
acids in athletes. In this review, only english-language clini-
cal studies evaluating a speciﬁc eﬀect of amino acid (used
alone and not in combination with other nutrients) were
considered. PubMed, Web of Science, and Science Direct
were used for selecting studies. Amino acids selected in this
review are those whose literature is suﬃciently important
Handling Editor: F. Blachier.
* Arthur Goron
Laboratory of Fundamental and Applied Bioenergetics
(LBFA), INSERM U 1055 and SFR Environmental
and Systems Biology (BEeSy), University Grenoble Alpes,