Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2023 Oct;62(7):2963-2975.
doi: 10.1007/s00394-023-03212-x. Epub 2023 Jul 14.

Effect of isolated and combined ingestion of caffeine and citrulline malate on resistance exercise and jumping performance: a randomized double-blind placebo-controlled crossover study

Markus Estifanos Haugen  1 , Fredrik Tonstad Vårvik  2   3 , Jozo Grgic  4 , Henrik Studsrud  5 , Espen Austheim  5 , Erik Mathias Zimmermann  5 , Hallvard Nygaard Falch  5 , Stian Larsen  5 , Roland van den Tillaar  5 , Thomas Bjørnsen  2   3
Affiliations
Randomized Controlled Trial

Effect of isolated and combined ingestion of caffeine and citrulline malate on resistance exercise and jumping performance: a randomized double-blind placebo-controlled crossover study

Markus Estifanos Haugen et al. Eur J Nutr. 2023 Oct.

Abstract

Purpose: The aim of this study was to explore the isolated and combined effects of caffeine and citrulline malate (CitMal) on jumping performance, muscular strength, muscular endurance, and pain perception in resistance-trained participants.

Methods: Using a randomized and double-blind study design, 35 resistance-trained males (n = 18) and females (n = 17) completed four testing sessions following the ingestion of isolated caffeine (5 mg/kg), isolated CitMal (12 g), combined doses of caffeine and CitMal, and placebo. Supplements were ingested 60 min before performing a countermovement jump (CMJ) test (outcomes included jump height, rate of force development, peak force, and peak power), one-repetition maximum (1RM) squat and bench press, and repetitions to muscular failure in the squat and bench press with 60% of 1RM. Pain perception was evaluated following the repetitions to failure tests. The study was registered at ISRCTN (registration number: ISRCTN11694009).

Results: Compared to the placebo condition, isolated caffeine ingestion and co-ingestion of caffeine and CitMal significantly enhanced strength in 1RM bench press (Cohen's d: 0.05-0.06; 2.5-2.7%), muscular endurance in the squat (d: 0.46-0.58; 18.6-18.7%) and bench press (d: 0.48-0.64; 9.3-9.5%). However, there was no significant difference between isolated caffeine ingestion and caffeine co-ingested with CitMal, and isolated CitMal supplementation did not have an ergogenic effect in any outcome. No main effect of condition was found in the analysis for CMJ-derived variables, 1RM squat and pain perception.

Conclusion: Caffeine ingestion appears to be ergogenic for muscular strength and muscular endurance, while adding CitMal does not seem to further enhance these effects.

Keywords: Bench press; Force; Hypertrophy; Nutritional supplements; Power; Resistance training; Sports nutrition; Squat.

PubMed Disclaimer

Conflict of interest statement

Markus Haugen has received payment for sports nutrition consultancy work with Empire Athletics, Norway. The other authors declare that there is no conflict of interest regarding the content of this article.

Figures

Fig. 1
Fig. 1
Overview of the study design. CMJ countermovement jump, RM repetitions maximum, SQ squat, BP bench press, AMRAP as many repetitions as possible, PP pain perception
Fig. 2
Fig. 2
Timeline of test day. Questionnaire one was only given on familiarization (personal data, weight, food log, caffeine log, resistance training experience). Questionnaire two included evaluation of the effectiveness of the blinding. CMJ countermovement jump, RM repetition maximum, SQ squat, BP bench press, AMRAP as many repetitions as possible
Fig. 3
Fig. 3
Percentage difference compared to placebo. Mean ± 95% confidence interval for A Rate of force development, B Power, C Jump height, D, Force, E 1 RM Squat, F 1 RM Bench press, G RTF Squat, and H, RTF Bench Press. 1 RM 1 repetition maximum, RTF Repetitions to failure. *Indicates significant different from placebo (p < 0.05), **Indicates significant differences from placebo (p < 0.01), and ***Indicates significant differences from placebo (p < 0.001)
Fig. 4
Fig. 4
Data are presented as group mean ± 95% confidence interval and individual data (dark points are males and white points are females) for A Rate of force development, B Power, C Squat 1RM, D Jump height, E Force, and F Bench press 1RM. 1RM 1 repetition maximum
Fig. 5
Fig. 5
Data are presented as group mean ± 95% confidence interval and individual data (dark points are males and white points are females) for A Bench press repetitions to failure, B Squat repetitions to failure, C Numerical rating scale (pain) bench press, and D Numerical rating scale (pain) for squat. NRS numerical rating scale, RTF repetitions to failure
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Aguilar-Navarro M, Muñoz G, Salinero JJ, et al. Urine caffeine concentration in doping control samples from 2004 to 2015. Nutrients. 2019 doi: 10.3390/nu11020286. - DOI - PMC - PubMed
    1. Grgic J, Grgic I, Pickering C, et al. Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. Br J Sports Med. 2020;54:681–688. doi: 10.1136/bjsports-2018-100278. - DOI - PubMed
    1. Grgic J. Exploring the minimum ergogenic dose of caffeine on resistance exercise performance: a meta-analytical approach. Nutrition. 2022;97:111604. doi: 10.1016/j.nut.2022.111604. - DOI - PubMed
    1. Grgic J, Mikulic P, Schoenfeld BJ, et al. The influence of caffeine supplementation on resistance exercise: a review key points. Sports Med. 2019;49:17–30. doi: 10.1007/s40279-018-0997-y. - DOI - PubMed
    1. Tarnopolsky MA. Effect of caffeine on the neuromuscular system—potential as an ergogenic aid. Appl Physiol Nutr Metab. 2008;33:1284–1289. doi: 10.1139/H08-121. - DOI - PubMed

Publication types

LinkOut - more resources