{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T14:13:10Z","timestamp":1792159990306,"version":"4.4.0"},"reference-count":45,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2025,8,27]],"date-time":"2025-08-27T00:00:00Z","timestamp":1756252800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background: L-carnitine supplementation is thought to enhance exercise performance, particularly in moderate and high-intensity activities, but evidence supporting this is mixed. This study aimed to assess whether acute L-carnitine tartrate supplementation could improve CrossFit\u00ae performance, specifically during the \u201cCindy\u201d workout, a high-intensity exercise protocol. Methods: In a randomized, double-blind, placebo-controlled crossover design, 20 trained male recreational CrossFit\u00ae athletes completed the \u201cCindy\u201d workout within a 20 min period after ingesting either 3 g of L-carnitine tartrate or a placebo 90 min before exercise. Performance was measured by total repetitions completed. Secondary outcomes included ratings of perceived exertion (RPE), gastrointestinal issues, and blood pressure (BP) measurements. Results: The results showed that L-carnitine supplementation did not significantly affect the number of repetitions performed (202.4 \u00b1 69.9 vs. 204.5 \u00b1 78.8, p = 0.810) compared to the placebo. There were also no significant differences in RPE (6.3 \u00b1 1.5 vs. 6.9 \u00b1 1.4, p = 0.180) or BP changes between groups. However, 10% of participants reported difficulty sleeping after L-carnitine supplementation. Conclusions: The findings suggest that 3 g of L-carnitine tartrate does not enhance CrossFit\u00ae performance in recreational athletes. Further research is needed to clarify its potential benefits, especially with larger samples and consideration of factors like sex and carbohydrate co-ingestion.<\/jats:p>","DOI":"10.3390\/nu17172784","type":"journal-article","created":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T07:43:16Z","timestamp":1756366996000},"page":"2784","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Acute L-Carnitine Supplementation Does Not Improve CrossFit\u00ae Performance: A Randomized, Double-Blind, Placebo-Controlled Crossover Study"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4267-9950","authenticated-orcid":false,"given":"Asli","family":"Devrim-Lanpir","sequence":"first","affiliation":[{"name":"School of Health and Human Performance, Dublin City University, D09 V209 Dublin, Ireland"},{"name":"Department of Nutrition and Dietetics, Faculty of Health Sciences, Istanbul Medeniyet University, 34862 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lucero Salazar","family":"Velasco","sequence":"additional","affiliation":[{"name":"Faculty of Higher Studies Zaragoza, National Autonomous University of Mexico, Mexico 09230, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fanny Guadalupe","family":"Ramirez Lara","sequence":"additional","affiliation":[{"name":"Faculty of Higher Studies Zaragoza, National Autonomous University of Mexico, Mexico 09230, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9013-295X","authenticated-orcid":false,"given":"Azucena","family":"Ojeda Sanchez","sequence":"additional","affiliation":[{"name":"Faculty of Higher Studies Zaragoza, National Autonomous University of Mexico, Mexico 09230, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rachel","family":"Kimble","sequence":"additional","affiliation":[{"name":"Division of Sport and Exercise Science, School of Health and Life Sciences, University of the West of Scotland, Blantyre G72 0LH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2159-5782","authenticated-orcid":false,"given":"Reza","family":"Zare","sequence":"additional","affiliation":[{"name":"SRH Campus Hamburg, Berlin University of Applied Sciences, 20095 Hamburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fatma Esra","family":"Gunes","sequence":"additional","affiliation":[{"name":"Department of Nutrition and Dietetics, Faculty of Health Sciences, Istanbul Medeniyet University, 34862 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2412-9103","authenticated-orcid":false,"given":"Beat","family":"Knechtle","sequence":"additional","affiliation":[{"name":"Medbase St. Gallen Am Vadianplatz, Vadianstrasse 26, 9001 St. Gallen, Switzerland"},{"name":"Institute of Primary Care, University of Zurich, Pestalozzistrasse 24, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1247-6754","authenticated-orcid":false,"given":"Katja","family":"Weiss","sequence":"additional","affiliation":[{"name":"Institute of Primary Care, University of Zurich, Pestalozzistrasse 24, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6436-6306","authenticated-orcid":false,"given":"Thomas","family":"Rosemann","sequence":"additional","affiliation":[{"name":"Institute of Primary Care, University of Zurich, Pestalozzistrasse 24, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6837-408X","authenticated-orcid":false,"given":"Katie","family":"Heinrich","sequence":"additional","affiliation":[{"name":"Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA"},{"name":"Department of Research and Evaluation, The Phoenix, Manhattan, KS 66502, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/s12291-014-0437-1","article-title":"Effect of L-Carnitine Supplementation on Nutritional Status and Physical Performance Under Calorie Restriction","volume":"30","author":"Jain","year":"2015","journal-title":"Indian J. Clin. Biochem."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Wax, B., Kerksick, C.M., Jagim, A.R., Mayo, J.J., Lyons, B.C., and Kreider, R.B. (2021). Creatine for Exercise and Sports Performance, with Recovery Considerations for Healthy Populations. Nutrients, 13.","DOI":"10.3390\/nu13061915"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Vecchio, M., Chiaramonte, R., Testa, G., and Pavone, V. (2021). Clinical Effects of L-Carnitine Supplementation on Physical Performance in Healthy Subjects, the Key to Success in Rehabilitation: A Systematic Review and Meta-Analysis from the Rehabilitation Point of View. J. Funct. Morphol. Kinesiol., 6.","DOI":"10.3390\/jfmk6040093"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Mielgo-Ayuso, J., Pietrantonio, L., Viribay, A., Calleja-Gonz\u00e1lez, J., Gonz\u00e1lez-Bernal, J., and Fern\u00e1ndez-L\u00e1zaro, D. (2021). Effect of Acute and Chronic Oral L-Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review. Nutrients, 13.","DOI":"10.3390\/nu13124359"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1007\/s00421-005-0020-9","article-title":"L-Carnitine and the Recovery from Exhaustive Endurance Exercise: A Randomised, Double-Blind, Placebo-Controlled Trial","volume":"95","author":"Stuessi","year":"2005","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1111\/sms.12885","article-title":"Increasing Skeletal Muscle Carnitine Availability Does Not Alter the Adaptations to High-Intensity Interval Training","volume":"28","author":"Shannon","year":"2018","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1007\/s00706-005-0335-6","article-title":"Endurance Exercise Training and L-Carnitine Supplementation Stimulates Gene Expression in the Blood and Muscle Cells in Young Athletes and Middle Aged Subjects","volume":"136","author":"Lohninger","year":"2005","journal-title":"Monatshefte Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2422","DOI":"10.1016\/j.bbamcr.2016.01.023","article-title":"Carnitine Transport and Fatty Acid Oxidation","volume":"1863","author":"Longo","year":"2016","journal-title":"Biochim. Biophys. Acta (BBA)\u2014Mol. Cell Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1059","DOI":"10.1113\/jphysiol.2011.225011","article-title":"Regulation and Limitations to Fatty Acid Oxidation during Exercise","volume":"590","author":"Jeppesen","year":"2012","journal-title":"J. Physiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/0304-4165(90)90147-O","article-title":"Metabolic Changes Induced by Maximal Exercise in Human Subjects Following L-Carnitine Administration","volume":"1034","author":"Siliprandi","year":"1990","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Caballero-Garc\u00eda, A., Noriega-Gonz\u00e1lez, D.C., Roche, E., Drobnic, F., and C\u00f3rdova, A. (2023). Effects of L-Carnitine Intake on Exercise-Induced Muscle Damage and Oxidative Stress: A Narrative Scoping Review. Nutrients, 15.","DOI":"10.3390\/nu15112587"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1016\/j.jcis.2021.11.056","article-title":"How Do Chain Lengths of Acyl-l-Carnitines Affect Their Surface Adsorption and Solution Aggregation?","volume":"609","author":"Liu","year":"2022","journal-title":"J. Colloid Interface Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.scispo.2018.09.005","article-title":"The Effects of L-Carnitine Supplementation in Athletic Performance","volume":"34","author":"Oliveira","year":"2019","journal-title":"Sci. Sports"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1016\/j.nut.2004.04.003","article-title":"Supplementation of L-Carnitine in Athletes: Does It Make Sense?","volume":"20","author":"Karlic","year":"2004","journal-title":"Nutrition"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1186\/s40798-018-0124-5","article-title":"CrossFit Overview: Systematic Review and Meta-Analysis","volume":"4","author":"Claudino","year":"2018","journal-title":"Sports Med.-Open"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/j.orthtr.2020.07.001","article-title":"CrossFit\u00ae\u2014Development, Benefits and Risks","volume":"36","author":"Wagener","year":"2020","journal-title":"Sports Orthop. Traumatol."},{"key":"ref_17","unstructured":"(2024, July 04). CrossFit. Available online: https:\/\/www.crossfit.com\/map."},{"key":"ref_18","first-page":"670","article-title":"CrossFit\u00ae Training Strategies from the Perspective of Concurrent Training: A Systematic Review","volume":"19","author":"Schlegel","year":"2020","journal-title":"J. Sports Sci. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1123\/ijsnem.2020-0223","article-title":"A Systematic Review of CrossFit\u00ae Workouts and Dietary and Supplementation Interventions to Guide Nutritional Strategies and Future Research in CrossFit\u00ae","volume":"31","author":"Souza","year":"2021","journal-title":"Int. J. Sport Nutr. Exerc. Metab."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1186\/s12970-016-0150-y","article-title":"The Effect of Six Days of Dietary Nitrate Supplementation on Performance in Trained CrossFit Athletes","volume":"13","author":"Kramer","year":"2016","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Stein, J.A., Ramirez, M., and Heinrich, K.M. (2020). Acute Caffeine Supplementation Does Not Improve Performance in Trained CrossFit\u00ae Athletes. Sports, 8.","DOI":"10.3390\/sports8040054"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2301384","DOI":"10.1080\/15502783.2023.2301384","article-title":"The Dose-Dependent Effect of Caffeine Supplementation on Performance, Reaction Time and Postural Stability in CrossFit\u2014A Randomized Placebo-Controlled Crossover Trial","volume":"21","author":"Malik","year":"2024","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Machek, S.B., Zawieja, E.E., Heileson, J.L., Harris, D.R., Wilburn, D.T., Fletcher, E.A., Cholewa, J.M., Szwengiel, A., Chmurzynska, A., and Willoughby, D.S. (2022). Human Serum Betaine and Associated Biomarker Concentrations Following a 14 Day Supplemental Betaine Loading Protocol and during a 28 Day Washout Period: A Pilot Investigation. Nutrients, 14.","DOI":"10.3390\/nu14030498"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Moro, T., Badiali, F., Fabbri, I., and Paoli, A. (2020). Betaine Supplementation Does Not Improve Muscle Hypertrophy or Strength Following 6 Weeks of Cross-Fit Training. Nutrients, 12.","DOI":"10.3390\/nu12061688"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e10200075","DOI":"10.1590\/s1980-6574202000040075","article-title":"Acute Effect of Sodium Bicarbonate Supplementation on the Performance during CrossFit\u00ae Training","volume":"26","author":"Toledo","year":"2020","journal-title":"Mot. Rev. Educ. Fis."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1186\/s41110-023-00193-z","article-title":"Prevalence of Dietary Supplement Consumption among CrossFit Practitioners","volume":"48","author":"Marques","year":"2023","journal-title":"Nutrire"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1190","DOI":"10.1016\/j.metabol.2009.11.012","article-title":"L-Carnitine l-Tartrate Supplementation Favorably Affects Biochemical Markers of Recovery from Physical Exertion in Middle-Aged Men and Women","volume":"59","author":"Ho","year":"2010","journal-title":"Metabolism"},{"key":"ref_28","first-page":"455","article-title":"The Effects of L-Carnitine L-Tartrate Supplementation on Hormonal Responses to Resistance Exercise and Recovery","volume":"17","author":"Kraemer","year":"2003","journal-title":"J. Strength Cond. Res."},{"key":"ref_29","unstructured":"(2024, May 30). Hydration for Health and Wellness. Available online: http:\/\/www.gssiweb.org:80\/sports-science-exchange\/article\/hydration-for-health-and-wellness."},{"key":"ref_30","unstructured":"(2024, July 04). SciELO-Brazil\u2014International Society for the Advancement of Kinanthropometry (ISAK) Global: International Accreditation Scheme of the Competent Anthropometrist International Society for the Advancement of Kinanthropometry (ISAK) Global: International Accreditation Scheme of the Competent Anthropometrist. Available online: https:\/\/www.scielo.br\/j\/rbcdh\/a\/wnxqYZCNbHc4NgwcC9kWGWP\/."},{"key":"ref_31","unstructured":"(2024, July 04). Research Randomizer. Available online: https:\/\/www.randomizer.org\/."},{"key":"ref_32","first-page":"114","article-title":"Acute Physiological Responses during Crossfit\u00ae Workouts","volume":"35","author":"Solana","year":"2015","journal-title":"Eur. J. Hum. Hum. Mov."},{"key":"ref_33","unstructured":"American College of Sports Medicine (2014). ACSM\u2019s Guidelines for Exercise Testing and Prescription, Lippincott Williams & Wilkins."},{"key":"ref_34","first-page":"109","article-title":"A New Approach to Monitoring Exercise Training","volume":"15","author":"Foster","year":"2001","journal-title":"J. Strength Cond. Res."},{"key":"ref_35","unstructured":"Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences, Lawrence Erlbaum Associates. [2nd ed.]."},{"key":"ref_36","first-page":"1","article-title":"Metabolic and Cardiovascular Response to the CrossFit Workout \u201cCindy\u201d","volume":"2","author":"Kliszczewicz","year":"2014","journal-title":"J. Sport Hum. Perform."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1186\/1550-2783-6-9","article-title":"Glycine Propionyl-L-Carnitine Produces Enhanced Anaerobic Work Capacity with Reduced Lactate Accumulation in Resistance Trained Males","volume":"6","author":"Jacobs","year":"2009","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"ref_38","first-page":"2","article-title":"Effect of Acute L-Carnitine Supplementation on Blood Lactate, Glucose, Aerobic and Anaerobic Performance in Elite Male Artistic Gymnasts","volume":"1","author":"Arazi","year":"2017","journal-title":"Balt. J. Sport Health Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1113\/jphysiol.2010.201343","article-title":"Chronic Oral Ingestion of L-Carnitine and Carbohydrate Increases Muscle Carnitine Content and Alters Muscle Fuel Metabolism during Exercise in Humans","volume":"589","author":"Wall","year":"2011","journal-title":"J. Physiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1038\/s41371-019-0248-1","article-title":"Effects of L-Carnitine Supplementation on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials","volume":"33","author":"Askarpour","year":"2019","journal-title":"J. Hum. Hypertens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.yrtph.2006.06.007","article-title":"Risk Assessment for Carnitine","volume":"46","author":"Hathcock","year":"2006","journal-title":"Regul. Toxicol. Pharmacol."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Liu, T., Deng, K., Xue, Y., Yang, R., Yang, R., Gong, Z., and Tang, M. (2022). Carnitine and Depression. Front. Nutr., 9.","DOI":"10.3389\/fnut.2022.853058"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"14","DOI":"10.3390\/sports2010014","article-title":"Music in CrossFit\u00ae\u2014Influence on Performance, Physiological, and Psychological Parameters","volume":"2","author":"Brupbacher","year":"2014","journal-title":"Sports"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1016\/j.jsams.2007.11.006","article-title":"Deception by Manipulating the Clock Calibration Influences Cycle Ergometer Endurance Time in Males","volume":"12","author":"Morton","year":"2009","journal-title":"J. Sci. Med. Sport"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Klier, K., D\u00f6rr, S., and Schmidt, A. (2021). High Sleep Quality Can Increase the Performance of CrossFit\u00ae Athletes in Highly Technical- and Cognitive-Demanding Categories. BMC Sports Sci. Med. Rehabil., 13.","DOI":"10.1186\/s13102-021-00365-2"}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/17\/17\/2784\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:34:07Z","timestamp":1760034847000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/17\/17\/2784"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,27]]},"references-count":45,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["nu17172784"],"URL":"https:\/\/doi.org\/10.3390\/nu17172784","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,27]]}}}