{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T02:05:26Z","timestamp":1791943526868,"version":"4.3.4"},"reference-count":35,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,4,25]],"date-time":"2025-04-25T00:00:00Z","timestamp":1745539200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union","award":["T2E\u0394K-00442"],"award-info":[{"award-number":["T2E\u0394K-00442"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: High-intensity functional training (HIFT) combines multijoint aerobic and resistance exercises. Despite its popularity, limited research has investigated dietary or supplementation strategies to enhance adaptations to HIFT. Hence, this study aimed to examine the effects of egg white and whey protein supplementation during HIFT on physical performance in trained individuals. Methods: Thirty recreationally trained volunteers (20 males, 10 females), aged 23\u201355, underwent 6 weeks of HIFT (three times\/week) while receiving 0.6 g\/kg\/day of egg white protein, whey protein, or maltodextrin (placebo) in a researcher-blinded, randomized, triple-crossover, and counterbalanced design, with 2 weeks of washout between supplements. Participants followed isoenergetic diets providing 1.0 g\/kg\/day of protein. Before and after each intervention, VO2max, the maximal strength (1 RM) and force\u2013velocity relationship of shoulder press, the peak torque and strength endurance of knee extensors and flexors, and the strength endurance of core muscles were measured. The training session load was monitored during each intervention period\u2019s first and last weeks. Data were analyzed by three-way ANOVA (supplement \u00d7 time \u00d7 sex), with repeated measures on supplement and time. Results: The duration, energy expenditure, training load score, and cardio load of each training session increased from the beginning to the end of each training period by 2\u201311% (p &lt; 0.05). The 1 RM of shoulder press and strength endurance of core muscles increased by 3\u20136% (p &lt; 0.001). Protein supplementation did not affect any of these outcomes. Conclusions: Short-term HIFT improved exercise capacity, upper-body strength, and core endurance. However, increasing protein intake from 1.0 to 1.6 g\/kg\/day did not further enhance performance.<\/jats:p>","DOI":"10.3390\/nu17091441","type":"journal-article","created":{"date-parts":[[2025,4,25]],"date-time":"2025-04-25T06:10:13Z","timestamp":1745561413000},"page":"1441","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Effects of Protein Supplementation During High-Intensity Functional Training on Physical Performance in Recreationally Trained Males and Females: A Randomized Controlled Trial"],"prefix":"10.3390","volume":"17","author":[{"given":"Christina","family":"Karpouzi","sequence":"first","affiliation":[{"name":"Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-1623-4392","authenticated-orcid":false,"given":"Ioannis","family":"Kosmidis","sequence":"additional","affiliation":[{"name":"Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5060-1950","authenticated-orcid":false,"given":"Anatoli","family":"Petridou","sequence":"additional","affiliation":[{"name":"Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriela","family":"Voulgaridou","sequence":"additional","affiliation":[{"name":"Department of Nutritional Sciences and Dietetics, International Hellenic University, 57400 Thermi, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sousana","family":"Papadopoulou","sequence":"additional","affiliation":[{"name":"Department of Nutritional Sciences and Dietetics, International Hellenic University, 57400 Thermi, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3382-0438","authenticated-orcid":false,"given":"Gregory","family":"Bogdanis","sequence":"additional","affiliation":[{"name":"School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8430-7231","authenticated-orcid":false,"given":"Vassilis","family":"Mougios","sequence":"additional","affiliation":[{"name":"Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Falk Neto, J.H., and Kennedy, M.D. (2019). 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