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Larrosa M, Gil-Izquierdo A, González-Rodríguez LG, Alférez MJM, San Juan AF, Sánchez-Gómez Á, Calvo-Ayuso N, Ramos-Álvarez JJ, Fernández-Lázaro D, Lopez-Grueso R, López-León I, Moreno-Lara J, Domínguez-Balmaseda D, Illescas-Quiroga R, Cuenca E, López T, Montoya JJ, Rodrigues-de-Souza DP, Carrillo-Alvarez E, Casado A, Rodriguez-Doñate B, Porta-Oliva M, Santiago C, Iturriaga T, De Lucas B, Solaesa ÁG, Montero-López MDP, Benítez De Gracia E, Veiga-Herreros P, Muñoz-López A, Orantes-Gonzalez E, Barbero-Alvarez JC, Cabeza-Ruiz R, Carnero-Diaz Á, Sospedra I, Fernández-Galván LM, Martínez-Sanz JM, Martín-Almena FJ, Pérez M, Guerra-Hernández EJ, López-Samanes Á, Sánchez-Oliver AJ, Domínguez R. Nutritional Strategies for Optimizing Health, Sports Performance, and Recovery for Female Athletes and Other Physically Active Women: A Systematic Review. Nutr Rev 2024:nuae082. [PMID: 38994896 DOI: 10.1093/nutrit/nuae082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
CONTEXT Despite the progress toward gender equality in events like the Olympic Games and other institutionalized competitions, and the rising number of women engaging in physical exercise programs, scientific studies focused on establishing specific nutritional recommendations for female athletes and other physically active women are scarce. OBJECTIVE This systematic review aimed to compile the scientific evidence available for addressing the question "What dietary strategies, including dietary and supplementation approaches, can improve sports performance, recovery, and health status in female athletes and other physically active women?" DATA SOURCES The Pubmed, Web of Science, and Scopus databases were searched. DATA EXTRACTION The review process involved a comprehensive search strategy using keywords connected by Boolean connectors. Data extracted from the selected studies included information on the number of participants and their characteristics related to sport practice, age, and menstrual function. DATA ANALYSIS A total of 71 studies were included in this review: 17 focused on the analysis of dietary manipulation, and 54 focused on the effects of dietary supplementation. The total sample size was 1654 participants (32.5% categorized as competitive athletes, 30.7% as highly/moderately trained, and 37.2% as physically active/recreational athletes). The risk of bias was considered moderate, mainly for reasons such as a lack of access to the study protocol, insufficient description of how the hormonal phase during the menstrual cycle was controlled for, inadequate dietary control during the intervention, or a lack of blinding of the researchers. CONCLUSION Diets with high carbohydrate (CHO) content enhance performance in activities that induce muscle glycogen depletion. In addition, pre-exercise meals with a high glycemic index or rich in CHOs increase CHO metabolism. Ingestion of 5-6 protein meals interspersed throughout the day, with each intake exceeding 25 g of protein favors anabolism of muscle proteins. Dietary supplements taken to enhance performance, such as caffeine, nitric oxide precursors, β-alanine, and certain sport foods supplements (such as CHOs, proteins, or their combination, and micronutrients in cases of nutritional deficiencies), may positively influence sports performance and/or the health status of female athletes and other physically active women. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. CRD480674.
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Affiliation(s)
- Mar Larrosa
- Departamento de Nutrición y Ciencia de los Alimentos, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Angel Gil-Izquierdo
- Research Group on Food and Nutrition (ALINUT), University of Alicante, 03690 Alicante, Spain
- Quality, Safety, and Bioactivity of Plant Foods Group, Department of Food Science and Technology, CEBAS-CSIC, University of Murcia, 30100 Murcia, Spain
| | - Liliana Guadalupe González-Rodríguez
- Departamento de Nutrición y Ciencia de los Alimentos, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
- VALORNUT Research Group, Complutense University of Madrid, 28040 Madrid, Spain
| | - María José Muñoz Alférez
- Department of Physiology (Faculty of Pharmacy, Cartuja University Campus), Institute of Nutrition and Food Technology "José Mataix", University of Granada, 18071 Granada, Spain
| | - Alejandro F San Juan
- Department of Health and Human Performance, Faculty of Physical Activity and Sports Sciences (INEF), Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | | | - Natalia Calvo-Ayuso
- Departamento de Enfermería y Fisioterapia, Campus de Ponferrada, Universidad de León, 24401 Ponferrada, Spain
| | - Juan José Ramos-Álvarez
- School of Sport Medicine, Department of Radiology, Rehabilitation and Physiotherapy, Complutense University Madrid, 28040 Madrid, Spain
| | - Diego Fernández-Lázaro
- Department of Cellular Biology, Genetics, Histology and Pharmacology, Faculty of Health Sciences, University of Valladolid, 42004 Soria, Spain
- Neurobiology Research Group, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain
| | - Raúl Lopez-Grueso
- Facultad de Ciencias de la Salud, Universidad Isabel I, 09003 Burgos, Spain
| | - Inmaculada López-León
- Departamento de Motricidad Humana y Rendimiento Deportivo, University of Seville, 41013 Seville, Spain
| | - Javier Moreno-Lara
- Departamento de Motricidad Humana y Rendimiento Deportivo, University of Seville, 41013 Seville, Spain
| | - Diego Domínguez-Balmaseda
- Facultad de Ciencias de la Actividad Física, Deporte y Fisioterapia, Universidad Europea de Madrid, 28670 Villaviciosa de Odón, Spain
| | - Román Illescas-Quiroga
- Departamento de Enfermería y Fisioterapia, University of Alcala, 28805 Alcalá de Henares, Spain
| | - Eduardo Cuenca
- Academia de Guardias y Suboficiales de la Guardia Civil, 23440 Baeza, Spain
| | - Teba López
- Academia de Guardias y Suboficiales de la Guardia Civil, 23440 Baeza, Spain
| | - Juan José Montoya
- School of Sport Medicine, Department of Radiology, Rehabilitation and Physiotherapy, Complutense University Madrid, 28040 Madrid, Spain
| | - Daiana Priscila Rodrigues-de-Souza
- Departamento de Enfermería, Farmacología y Fisioterapia, 14004 Córdoba, Spain
- Maimonides Biomedical Research Institute of Córdoba (IMIBIC), 14004 Córdoba, Spain
| | - Elena Carrillo-Alvarez
- Global Research on Wellbeing (GRoW) Research Group, Blanquerna School of Health Sciences, University Ramon Llull, 08025 Barcelona, Spain
| | - Arturo Casado
- Centro de Investigación en Ciencias del Deporte, Universidad Rey Juan Carlos, 28943 Fuenlabrada, Spain
| | | | - Mireia Porta-Oliva
- Faculty of Food Technology, Autonomous University of Barcelona (UAB), Bellaterra, Spain
- FC Barcelona Medical Department, FC Barcelona, 08028 Barcelona, Spain
- Catalan School of Kinanthropometry, INEFC, 0838 Barcelona, Spain
| | - Catalina Santiago
- Facultad de Ciencias de la Actividad Física, Deporte y Fisioterapia, Universidad Europea de Madrid, 28670 Villaviciosa de Odón, Spain
| | - Támara Iturriaga
- Facultad de Ciencias de la Actividad Física, Deporte y Fisioterapia, Universidad Europea de Madrid, 28670 Villaviciosa de Odón, Spain
| | - Beatriz De Lucas
- Facultad de Ciencias de la Actividad Física, Deporte y Fisioterapia, Universidad Europea de Madrid, 28670 Villaviciosa de Odón, Spain
| | | | | | - Elvira Benítez De Gracia
- Facultad de Ciencias de la Salud, Universidad Alfonso X El Sabio, 28691 Villanueva de la Cañada, Spain
| | - Pablo Veiga-Herreros
- Facultad de Ciencias de la Salud, Universidad Alfonso X El Sabio, 28691 Villanueva de la Cañada, Spain
| | - Alejandro Muñoz-López
- Departamento de Motricidad Humana y Rendimiento Deportivo, University of Seville, 41013 Seville, Spain
| | - Eva Orantes-Gonzalez
- Department of Sports and Computer Science, Faculty of Sports, University of Pablo de Olavide, 41013 Seville, Spain
| | | | - Ruth Cabeza-Ruiz
- Departamento de Motricidad Humana y Rendimiento Deportivo, University of Seville, 41013 Seville, Spain
| | - Ángel Carnero-Diaz
- Departamento de Educación Física y Deportiva, University of Seville, 41013 Seville, Spain
| | - Isabel Sospedra
- Nursing Department, Faculty of Health Sciences, University of Alicante, 03690 San Vicente del Raspeig, Spain
| | | | - José Miguel Martínez-Sanz
- Nursing Department, Faculty of Health Sciences, University of Alicante, 03690 San Vicente del Raspeig, Spain
| | | | - Margarita Pérez
- Department of Health and Human Performance, Faculty of Physical Activity and Sports Sciences (INEF), Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Eduardo J Guerra-Hernández
- Departamento de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Granada, 18011 Granada, Spain
| | - Álvaro López-Samanes
- Faculty of Human and Social Sciences, Universidad Pontificia Comillas, 28049 Madrid, Spain
| | - Antonio Jesús Sánchez-Oliver
- Departamento de Motricidad Humana y Rendimiento Deportivo, University of Seville, 41013 Seville, Spain
- Studies Research Group in Neuromuscular Responses (GEPREN), University of Lavras, 37203-202 Lavras, Brazil
| | - Raúl Domínguez
- Departamento de Motricidad Humana y Rendimiento Deportivo, University of Seville, 41013 Seville, Spain
- Studies Research Group in Neuromuscular Responses (GEPREN), University of Lavras, 37203-202 Lavras, Brazil
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Bougrine H, Ammar A, Salem A, Trabelsi K, Żmijewski P, Jahrami H, Chtourou H, Souissi N. Effects of Different Caffeine Dosages on Maximal Physical Performance and Potential Side Effects in Low-Consumer Female Athletes: Morning vs. Evening Administration. Nutrients 2024; 16:2223. [PMID: 39064667 PMCID: PMC11279619 DOI: 10.3390/nu16142223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/01/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
While previous studies have explored a range of factors governing the optimal use of caffeine (CAF) in athletes, limited research has explored how time of day (TOD) affects the ergogenic effects of various CAF dosages on physical performance. This study aimed to increase knowledge about how different recommended CAF doses (3 mg/kg vs. 6 mg/kg) ingested at different TODs affected maximal high-intensity physical performance and the perception of potential side effects in female athletes. In this double-blind, randomized, and counterbalanced study, 15 low CAF consumer athletes (aged 18.3 ± 0.5 y) underwent six trials, including three testing conditions assessed across two TODs: one in the morning (08:00 a.m.) and one in the evening (06:00 p.m.). During each condition, the participants ingested either a placebo, 3 mg/kg CAF (CAF (3 mg)), or 6 mg/kg CAF (CAF (6 mg)) capsules 60 min before each test with an in-between washout period of at least 72 h. In each trial, the participants performed a countermovement jumps test (CMJ), a modified agility t test (MATT), a repeated sprint ability (RSA), a rating of perceived exertion (RPE), and finally, a CAF side effects questionnaire. Our findings indicate the absence of an ergogenic effect on CMJ, MAT, and RSA performance in the evening after administering CAF (3 mg) or CAF (6 mg) compared to a placebo. Likewise, when CAF was ingested in the morning, there was an improvement in these performances with both CAF (3 mg) and CAF (6 mg), with greater improvement observed after CAF (6 mg). Additionally, neither the CAF dosage nor the TOD had a significant effect on the RPE. The occurrence of side effects increased significantly after the evening ingestion of CAF, particularly with a moderate dose of CAF (6 mg). Our findings indicate that the effectiveness of CAF depends on the TOD and CAF dosage. When ingested in the morning, a moderate dose of CAF (6 mg), rather than CAF (3 mg), is more effective in improving short-term physical performance without affecting CAF side effects in female athletes. Nevertheless, when ingested in the evening, neither dose was sufficient to enhance short-term physical performance, and both dosages increased the incidence of CAF side effects, particularly at a moderate dose.
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Affiliation(s)
- Houda Bougrine
- High Institute of Sport and Physical Education Gafsa, University of Gafsa, Gafsa 2100, Tunisia;
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (H.C.); (N.S.)
| | - Achraf Ammar
- Department of Training and Movement Science, Institute of Sport Science, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- High Institute of Sport and Physical Education Sfax, University of Sfax, Sfax 3000, Tunisia;
- Research Laboratory, Molecular Bases of Human Pathology, LR19ES13, Faculty of Medicine of Sfax, University of Sfax, Sfax 3029, Tunisia
| | - Atef Salem
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (H.C.); (N.S.)
- Department of Training and Movement Science, Institute of Sport Science, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- High Institute of Sport and Physical Education Sfax, University of Sfax, Sfax 3000, Tunisia;
| | - Khaled Trabelsi
- High Institute of Sport and Physical Education Sfax, University of Sfax, Sfax 3000, Tunisia;
- Research Laboratory, Education, Motricity, Sport and Health (EM2S), LR15JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia
| | - Piotr Żmijewski
- Faculty of Physical Education, Gdansk University of Physical Education and Sport, 80-336 Gdansk, Poland;
| | - Haitham Jahrami
- Department of Psychiatry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama 323, Bahrain;
- Ministry of Health, Manama 410, Bahrain
| | - Hamdi Chtourou
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (H.C.); (N.S.)
- High Institute of Sport and Physical Education Sfax, University of Sfax, Sfax 3000, Tunisia;
| | - Nizar Souissi
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (H.C.); (N.S.)
- High Institute of Sport and Physical Education Ksar-Saïd, Manouba University, Mannouba 2010, Tunisia
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Mor A, Acar K, Alexe DI, Mor H, Abdioğlu M, Man MC, Karakaș F, Waer FB, Yılmaz AK, Alexe CI. Moderate-dose caffeine enhances anaerobic performance without altering hydration status. Front Nutr 2024; 11:1359999. [PMID: 39050139 PMCID: PMC11267619 DOI: 10.3389/fnut.2024.1359999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 06/26/2024] [Indexed: 07/27/2024] Open
Abstract
The effects of direct nutritional supplements on athletic performance are still being investigated and arouse curiosity. Only one study in the literature was found that investigated the kicking speed performance of futsal players following low-dose caffeine supplementation (3 mg/kg); thus, the question of whether caffeine supplementation improves kicking speed as well as essential physical parameters in soccer players is still controversial. Therefore, the aim of this study was to determine the effect of caffeine supplementation on vertical jump (VJ), sprint, reaction time, balance, change of direction (COD), and ball-kicking speed in soccer players. In a double-blind, cross-over design, nine moderately trained male soccer players (21.11 ± 2.02 years, 171.22 ± 6.14 cm, 71.78 ± 10.02 kg) consumed caffeine (6 mg/kg) or a placebo 60 min before completing balance, reaction time, vertical jump, agility, 30 m sprint, and ball-kicking speed tests. Greater VJ height (p = 0.01) and power (p = 0.08), and faster completion time according to the Illinois Agility Test (p = 0.08) were found following caffeine supplementation compared to placebo. Elapsed time (p = 0.01), average (p = 0.01) time, and the slowest reaction times (p = 0.016) were significantly reduced after caffeine consumption compared to placebo supplementation. Caffeine intake significantly improved VJ, agility, and reaction time (p < 0.05) but did not affect 30 m sprint, ball-kicking speed, balance, and RPE values in soccer players (p > 0.05). Although non-significant, caffeine intake also improved sprint (0.67%) and ball kicking (2.7%) performance percentages. Also, caffeine consumption did not induce dehydration, and the athletes' body hydration levels were normal. These findings support the use of caffeine supplementation as an effective nutritional ergogenic aid to enhance anaerobic performance, at least for vertical jumps, COD speed, and reaction time, in trained male soccer players.
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Affiliation(s)
- Ahmet Mor
- Department of Coaching Education, Faculty of Sport Sciences, Sinop University, Sinop, Türkiye
| | - Kürşat Acar
- Department of Physical Education and Sports, Faculty of Sport Sciences, Sinop University, Sinop, Türkiye
| | - Dan Iulian Alexe
- Department of Physical and Occupational Therapy, “Vasile Alecsandri” University of Bacau, Bacau, Romania
| | - Hakkı Mor
- Department of Coaching Education, Yasar Doğu Faculty of Sport Sciences, Ondokuz Mayıs University, Samsun, Türkiye
| | - Mekki Abdioğlu
- Faculty of Sport Sciences, Institute of Health Sciences, Ankara University, Ankara, Türkiye
| | - Maria Cristina Man
- Department of Physical Education, 1 Decembrie 1918 University, Alba Iulia, Romania
| | - Fatih Karakaș
- Department of Physical Education and Sports, Faculty of Sport Sciences, Sinop University, Sinop, Türkiye
| | - Fatma Ben Waer
- Research Laboratory Education, Motricité, Sport et Santé (EM2S) LR19JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax, Tunisia
| | - Ali Kerim Yılmaz
- Recreation Department, Yasar Doğu Faculty of Sport Sciences, Ondokuz Mayıs University, Samsun, Türkiye
| | - Cristina Ioana Alexe
- Department of Physical Education and Sports Performance, “Vasile Alecsandri” University of Bacau, Bacau, Romania
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Bougrine H, Ammar A, Salem A, Trabelsi K, Jahrami H, Chtourou H, Souissi N. Optimizing Short-Term Maximal Exercise Performance: The Superior Efficacy of a 6 mg/kg Caffeine Dose over 3 or 9 mg/kg in Young Female Team-Sports Athletes. Nutrients 2024; 16:640. [PMID: 38474768 PMCID: PMC10935148 DOI: 10.3390/nu16050640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Caffeine (CAF) is among the most extensively researched dietary supplements worldwide. However, little is known about the relationship between dosage and performance enhancement, particularly in female athletes. This study aimed to explore the effects of three different CAF dosages (3 mg·kg-1, 6 mg·kg-1, and 9 mg·kg-1) on high-intensity exercise and the prevalence of undesirable side effects related to these doses among female team-sports athletes. All participants (n = 16; age: 16.9 ± 0.6 y; height: 1.64 ± 0.1 m; BMI: 21.6 ± 1.5 kg·m-2) were mild CAF consumers. This study had a randomized, crossover, double-blind design in which each athlete performed four experimental sessions after ingesting either a placebo (PLAC), 3 mg·kg-1 CAF (CAF-3), 6 mg·kg-1 CAF (CAF-6), or 9 mg·kg-1 of CAF (CAF-9), with an in-between washout period of at least 72 h. In each experimental session, 60 min after ingesting the capsules, participants underwent a countermovement jumps test (CMJ), modified agility t-test (MATT), repeated sprint ability (RSA) test, and a rating of perceived exertion (RPE) and completed the CAF side effects questionnaire. Our findings revealed that in comparison to the PLAC condition, the MATT, RSAmean, and RSAbest performances were significantly greater only under the CAF-6 and CAF-9 conditions. Although the RPE scores remained unchanged, CMJ performance improved under all CAF conditions. All the performance outcomes were better for the CAF-6 and CAF-9 conditions than for the CAF-3 condition. Notably, no significant difference between the CAF-6 and CAF-9 conditions was observed for any of these parameters despite the highest incidence of side effects being noted for the CAF-9 condition. In summary, our findings highlight the recommendation for a moderate CAF dosage of 6 mg·kg-1 rather than 3 or 9 mg·kg-1 to enhance various aspects of short-term maximal performance in mild-CAF-consumer female team-sports athletes while mitigating the occurrence of adverse CAF side effects.
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Affiliation(s)
- Houda Bougrine
- High Institute of Sport and Physical Education Gafsa, University of Gafsa, Gafsa 2100, Tunisia;
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (N.S.)
| | - Achraf Ammar
- High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia;
- Department of Training and Movement Science, Institute of Sport Science, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Research Laboratory, Molecular Bases of Human Pathology, LR19ES13, Faculty of Medicine of Sfax, University of Sfax, Sfax 3029, Tunisia
- Interdisciplinary Laboratory in Neurosciences, Physiology and Psychology: Physical Activity, Health and Learning (LINP2), UFR STAPS (Faculty of Sport Sciences), Université Paris Lumières (UPL), Paris Nanterre University, 92000 Nanterre, France
| | - Atef Salem
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (N.S.)
- High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia;
- Department of Training and Movement Science, Institute of Sport Science, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Khaled Trabelsi
- High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia;
- Research Laboratory, Education, Motricity, Sport and Health (EM2S), LR15JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia
| | - Haitham Jahrami
- Department of Psychiatry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama 323, Bahrain;
- Ministry of Health, Manama 410, Bahrain
| | - Hamdi Chtourou
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (N.S.)
- High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia;
| | - Nizar Souissi
- Physical Activity Research Unit, Sport and Health (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia (N.S.)
- High Institute of Sport and Physical Education Ksar-Saïd, Manouba University, Mannouba 2010, Tunisia
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Nuzzo JL, Pinto MD, Nosaka K, Steele J. Maximal Number of Repetitions at Percentages of the One Repetition Maximum: A Meta-Regression and Moderator Analysis of Sex, Age, Training Status, and Exercise. Sports Med 2024; 54:303-321. [PMID: 37792272 PMCID: PMC10933212 DOI: 10.1007/s40279-023-01937-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2023] [Indexed: 10/05/2023]
Abstract
The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) [REPS ~ %1RM relationship] is foundational knowledge in resistance exercise programming. The current REPS ~ %1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-individuals variation. Therefore, we conducted a meta-regression to estimate the mean and between-individuals standard deviation of the number of repetitions that can be completed at various percentages of 1RM. We also explored if the REPS ~ %1RM relationship is moderated by sex, age, training status, and/or exercise. A total of 952 repetitions-to-failure tests, completed by 7289 individuals in 452 groups from 269 studies, were identified. Study groups were predominantly male (66%), healthy (97%), < 59 years of age (92%), and resistance trained (60%). The bench press (42%) and leg press (14%) were the most commonly studied exercises. The REPS ~ %1RM relationship for mean repetitions and standard deviation of repetitions were best described using natural cubic splines and a linear model, respectively, with mean and standard deviation for repetitions decreasing with increasing %1RM. More repetitions were evident in the leg press than bench press across the loading spectrum, thus separate REPS ~ %1RM tables were developed for these two exercises. Analysis of moderators suggested little influences of sex, age, or training status on the REPS ~ %1RM relationship, thus the general main model REPS ~ %1RM table can be applied to all individuals and to all exercises other than the bench press and leg press. More data are needed to develop REPS ~ %1RM tables for other exercises.
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Affiliation(s)
- James L Nuzzo
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.
| | - Matheus D Pinto
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
| | - Kazunori Nosaka
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
| | - James Steele
- School of Sport, Health, and Social Sciences, Solent University, Southampton, UK
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Zart S, Brachtendorf M, Becker S, Fröhlich M. Isolated but not combined ergogenic effects of caffeine and L-arginine during an isokinetic knee extension. Front Nutr 2024; 10:1303805. [PMID: 38260064 PMCID: PMC10800533 DOI: 10.3389/fnut.2023.1303805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Introduction The use of single supplements as ergogenic aids to enhance performance in strength-oriented sports is widespread among athletes (74%). The aim of this study was to increase knowledge about the combined effects of caffeine and L-arginine dietary supplements on performance. Methods In this double-blind, randomized and counterbalanced crossover study, 29 participants (age: 23.2 ± 3.6 yr.; height: 181.0 ± 7.6 cm; weight: 77.0 ± 8.8 kg) each underwent six trials. In each trial performance tests were conducted to examine the effects of the supplement combinations on maximum (NmMax) and averaged torque (NmM), maximum (JMax) and averaged work (JM), the blockwise mean values of torque and work, and rate of perceived exertion (RPE) during an isokinetic leg extension task (90°·s-1) with the right leg for two sets of 40 repetitions and a set rest of 3 min on a dynamometer. The first and second trials were used to familiarize the participants with the movements in the dynamometer and no supplements were taken. After this 2-week pre-test trial, the supplement combinations of placebo/placebo, caffeine/placebo (5 mg·kg-1), L-arginine/placebo (0.15 g·kg-1), and caffeine/L-arginine (5 mg·kg-1 + 0.15 g·kg-1) were ingested. Results The main finding of this study is the absence of an ergogenic effect of the combined supplements caffeine and L-arginine during voluntary maximal isokinetic leg extensions, although an increase of 3.5% was noted for Nmmax compared to the placebo trial. However, the administration of caffeine was able to increase the NmMax of the quadriceps femoris muscle about 5.1% (p = 0.043). In addition, caffeine (4.2%, p = 0.026) and also L-arginine (4.2%, p = 0.040) significantly increased NmM over a complete set. No single or combined supplement had an effect on muscle fatigue looking at the blockwise mean values of torque and work or RPE (all p > 0.05). Conclusion The combination of caffeine and L-arginine was not superior to the isolated intake of both supplements in a strength-based exercise and a synergistic effect was absent.
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Affiliation(s)
- Sebastian Zart
- Department of Sports Science, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
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Almeida BA, Morales AP, Ribeiro JRC, Sampaio-Jorge F, Ribeiro YG, Barth T, Ribeiro BG. Impact of Caffeine Intake Strategies on Heart Rate Variability during Post-Exercise Recovery: A Systematic Review and Meta-Analysis. Curr Cardiol Rev 2024; 20:87-100. [PMID: 38494935 DOI: 10.2174/011573403x289842240307114736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/14/2024] [Accepted: 02/20/2024] [Indexed: 03/19/2024] Open
Abstract
OBJECTIVES The objective of this systematic review and meta-analysis is to evaluate the influence of caffeine (CAF) intake strategies, taking into account their form, timing, and dosage, on heart rate variability (HRV) indices in the post-exercise recovery period. METHODS The meta-analysis adhered to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and is registered in the PROSPERO database (CRD42023425885). A comprehensive literature search was carried out across MEDLINE, Web of Science, LILACS, and SCOPUS, concluding in May 2023. We concentrated on randomized clinical trials comparing CAF supplementation effects to placebo on HRV indices post-exercise in active adults aged 18 and above. The primary endpoint was the assessment of HRV indices, measured both prior to and following exercise. RESULTS Of the 10 studies included, 7 were used for the meta-analysis, and all contributed to the systematic review. The research explored a variety of CAF strategies, spanning different forms (capsule, drink, gum), times (10, 45, 60 min) and doses (2.1 to 6.0 mg/kg). The outcomes revealed no substantial variations between the placebo and CAF conditions in terms of both the square root of the average of successive squared differences between adjacent RR intervals (RMSSD) (standardized mean difference (SMD) -0.03, 95% CI -0.265 to 0.197, p=0.77) and high frequency (HF) index (SMD -0.061, 95% CI -0.272 to 0.150, p=0.57). Furthermore, metaregression analysis, employing a fixed-effects model and accounting for the administered CAF doses, revealed no significant correlation between caffeine doses and HRV indices (p>0.05). CONCLUSION In conclusion, there is moderate-certainty evidence suggesting that different CAF intake strategies, encompassing aspects such as form, time, and dose, do not have a significant impact on HRV indices recovery post-exercise (i.e., vagal modulation).
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Affiliation(s)
- Bianca Araujo Almeida
- Research and Innovation Laboratory in Sports and Nutrition Sciences (LAPICEN), Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Laboratory of Natural Products, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
| | - Anderson Pontes Morales
- Research and Innovation Laboratory in Sports and Nutrition Sciences (LAPICEN), Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Macaé Sports Secretary, City Government of Macaé (PMM), Macaé, RJ, Brazil
- Laboratory of Applied Physiology for Health, Performance, and Physical Education (LAPHPE), Higher Institutes of Education of CENSA (ISECENSA), Campos dos Goytacazes, RJ, Brazil
- Postgraduate Program in Nutrition, Institute of Nutrition, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | | | - Felipe Sampaio-Jorge
- Research and Innovation Laboratory in Sports and Nutrition Sciences (LAPICEN), Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Macaé Sports Secretary, City Government of Macaé (PMM), Macaé, RJ, Brazil
- Laboratory of Applied Physiology for Health, Performance, and Physical Education (LAPHPE), Higher Institutes of Education of CENSA (ISECENSA), Campos dos Goytacazes, RJ, Brazil
| | - Yasmin Garcia Ribeiro
- Research and Innovation Laboratory in Sports and Nutrition Sciences (LAPICEN), Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Laboratory of Natural Products, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
| | - Thiago Barth
- Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Laboratory of Natural Products, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
| | - Beatriz Gonçalves Ribeiro
- Research and Innovation Laboratory in Sports and Nutrition Sciences (LAPICEN), Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Postgraduate Program in Bioactive Products and Biosciences, Federal University of Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
- Postgraduate Program in Nutrition, Institute of Nutrition, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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Lowery LM, Anderson DE, Scanlon KF, Stack A, Escalante G, Campbell SC, Kerksick CM, Nelson MT, Ziegenfuss TN, VanDusseldorp TA, Kalman DS, Campbell BI, Kreider RB, Antonio J. International society of sports nutrition position stand: coffee and sports performance. J Int Soc Sports Nutr 2023; 20:2237952. [PMID: 37498180 PMCID: PMC10375938 DOI: 10.1080/15502783.2023.2237952] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/11/2023] [Indexed: 07/28/2023] Open
Abstract
Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).
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Affiliation(s)
- Lonnie M Lowery
- Walsh University, Department of Exercise Science, North Canton, OH, USA
- Nutrition, Exercise and Wellness Associates, Cuyahoga Falls, USA
| | - Dawn E Anderson
- Indiana Institute of Technology, Department of Biological and Physical Sciences, Fort Wayne, USA
| | - Kelsey F Scanlon
- Walsh University, Department of Exercise Science, North Canton, OH, USA
| | - Abigail Stack
- University of Mount Union, Department of Exercise, Nutrition, and Sport Science Alliance, USA
| | | | - Sara C Campbell
- The State University of New Jersey, Department of Kinesiology and Health, Rutgers, New Brunswick, USA
| | - Chad M Kerksick
- Lindenwood University, Exercise and Performance Nutrition Laboratory, St. Charles, USA
| | | | | | - Trisha A VanDusseldorp
- Bonafide Health, LLC p/b JDS Therapeutics, Harrison, USA
- Jacksonville University, Department of Health and Exercise Sciences, Jacksonville, USA
| | - Douglas S Kalman
- Nova Southeastern University, Department of Nutrition, College of Osteopathic Medicine, Fort Lauderdale, USA
| | - Bill I Campbell
- University of South Florida, Performance & Physique Enhancement Laboratory, Tampa, USA
| | - Richard B Kreider
- Texas A&M University, Exercise & Sport Nutrition Lab, Department of Kinesiology and Sports Management, College Station, USA
| | - Jose Antonio
- Nova Southeastern University, Department of Health and Human Performance, Davie, USA
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Komano Y, Fukao K, Shimada K, Naito H, Ishihara Y, Fujii T, Kokubo T, Daida H. Effects of Ingesting Food Containing Heat-Killed Lactococcus lactis Strain Plasma on Fatigue and Immune-Related Indices after High Training Load: A Randomized, Double-Blind, Placebo-Controlled, and Parallel-Group Study. Nutrients 2023; 15:nu15071754. [PMID: 37049594 PMCID: PMC10096552 DOI: 10.3390/nu15071754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/24/2023] [Accepted: 04/01/2023] [Indexed: 04/07/2023] Open
Abstract
Lactococcus lactis strain Plasma (LC-Plasma) is a unique lactic acid bacterium that activates plasmacytoid dendritic cells (pDCs). We evaluated the effect of LC-Plasma on fatigue indices and dendritic cells activity in athletes after 14 days’ continuous exercise load. Thirty-seven participants were divided into two groups and consumed placebo (PL) or LC-Plasma capsules (containing 100 billion cells) daily for 14 days. Maturation markers on dendritic cells, blood parameters, physiological indices, and fatigue-related indices were recorded on days 1 and 15 (before and after exercise). Cumulative days of symptoms relating to physical conditions were also recorded during the continuous exercise period. We observed that CD86 as a maturation marker on pDCs was significantly higher and that cumulative days of fatigue were significantly fewer in the LC-Plasma group than in the Placebo group on day 15. We also conducted 2 h ergometer exercise on day 15 to evaluate fatigue. The results showed that autonomic fatigue parameters (LF/HF) were significantly lower in the LC-Plasma group. These results suggest that LC-Plasma supplementation alleviates fatigue accumulation and increases pDC activity caused by a continuous high training load.
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Affiliation(s)
- Yuta Komano
- Kirin Holdings Company, Limited, Tokyo 164-0001, Japan
| | - Kosuke Fukao
- Graduate School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kazunori Shimada
- Graduate School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Hisashi Naito
- Graduate School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan
| | - Yoshihiko Ishihara
- School of Science and Technology for Future Life, Department of Humanities and Social Sciences, Tokyo Denki University, Tokyo 120-8551, Japan
| | - Toshio Fujii
- Kirin Holdings Company, Limited, Tokyo 164-0001, Japan
| | | | - Hiroyuki Daida
- Faculty of Health Science, Juntendo University, Tokyo 113-8421, Japan
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Marcus GM, Rosenthal DG, Nah G, Vittinghoff E, Fang C, Ogomori K, Joyce S, Yilmaz D, Yang V, Kessedjian T, Wilson E, Yang M, Chang K, Wall G, Olgin JE. Acute Effects of Coffee Consumption on Health among Ambulatory Adults. N Engl J Med 2023; 388:1092-1100. [PMID: 36947466 PMCID: PMC10167887 DOI: 10.1056/nejmoa2204737] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
BACKGROUND Coffee is one of the most commonly consumed beverages in the world, but the acute health effects of coffee consumption remain uncertain. METHODS We conducted a prospective, randomized, case-crossover trial to examine the effects of caffeinated coffee on cardiac ectopy and arrhythmias, daily step counts, sleep minutes, and serum glucose levels. A total of 100 adults were fitted with a continuously recording electrocardiogram device, a wrist-worn accelerometer, and a continuous glucose monitor. Participants downloaded a smartphone application to collect geolocation data. We used daily text messages, sent over a period of 14 days, to randomly instruct participants to consume caffeinated coffee or avoid caffeine. The primary outcome was the mean number of daily premature atrial contractions. Adherence to the randomization assignment was assessed with the use of real-time indicators recorded by the participants, daily surveys, reimbursements for date-stamped receipts for coffee purchases, and virtual monitoring (geofencing) of coffee-shop visits. RESULTS The mean (±SD) age of the participants was 39±13 years; 51% were women, and 51% were non-Hispanic White. Adherence to the random assignments was assessed to be high. The consumption of caffeinated coffee was associated with 58 daily premature atrial contractions as compared with 53 daily events on days when caffeine was avoided (rate ratio, 1.09; 95% confidence interval [CI], 0.98 to 1.20; P = 0.10). The consumption of caffeinated coffee as compared with no caffeine consumption was associated with 154 and 102 daily premature ventricular contractions, respectively (rate ratio, 1.51; 95% CI, 1.18 to 1.94); 10,646 and 9665 daily steps (mean difference, 1058; 95% CI, 441 to 1675); 397 and 432 minutes of nightly sleep (mean difference, 36; 95% CI, 25 to 47); and serum glucose levels of 95 mg per deciliter and 96 mg per deciliter (mean difference, -0.41; 95% CI, -5.42 to 4.60). CONCLUSIONS In this randomized trial, the consumption of caffeinated coffee did not result in significantly more daily premature atrial contractions than the avoidance of caffeine. (Funded by the University of California, San Francisco, and the National Institutes of Health; CRAVE ClinicalTrials.gov number, NCT03671759.).
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Affiliation(s)
- Gregory M Marcus
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - David G Rosenthal
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Gregory Nah
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Eric Vittinghoff
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Christina Fang
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Kelsey Ogomori
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Sean Joyce
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Defne Yilmaz
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Vivian Yang
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Tara Kessedjian
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Emily Wilson
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Michelle Yang
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Kathleen Chang
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Grace Wall
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
| | - Jeffrey E Olgin
- From the Division of Cardiology (G.M.M., G.N., E.W., M.Y., K.C., G.W., J.E.O.), the Department of Epidemiology and Biostatistics (E.V.), and the School of Medicine (K.O., S.J., V.Y.), University of California, San Francisco, San Francisco, the University of California, Irvine, School of Medicine, Irvine (C.F.); and the University of California, Berkeley, Berkeley (D.Y., T.J.)
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Saunders B, da Costa LR, de Souza RAS, Barreto G, Marticorena FM. Caffeine and sport. ADVANCES IN FOOD AND NUTRITION RESEARCH 2023; 106:95-127. [PMID: 37722778 DOI: 10.1016/bs.afnr.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Caffeine is a trimethylxanthine found in coffee and several other foods and beverages. Its stimulatory effects make it an interesting strategy to boost performance for athletic populations. Scientific evidence supports its efficacy to improve high-intensity endurance exercise, explosive and high-intensity efforts, resistance exercise, team sports and combat sports, though individual variation in the ergogenic response to caffeine exists. Supplementation can be taken in many forms including dissolved in water, via capsules, coffee, energy drinks and caffeinated gum; ingestion via capsules, dissolved in water or in caffeinated gum appear to be most effective. Variability in the exercise response following caffeine supplementation may be explained by genetic factors or habitual caffeine consumption. Caffeine is an excellent supplement for athletes looking to improve their exercise performance, though some consideration of side-effects and impact on sleep are warranted.
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Affiliation(s)
- Bryan Saunders
- Applied Physiology and Nutrition Research Group, School of Physical Education and Sport, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, SP, Brazil; Institute of Orthopedics and Traumatology, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, SP, Brazil.
| | - Larissa Registro da Costa
- Applied Physiology and Nutrition Research Group, School of Physical Education and Sport, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, SP, Brazil
| | - Ricardo Augusto Silva de Souza
- Applied Physiology and Nutrition Research Group, School of Physical Education and Sport, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, SP, Brazil
| | - Gabriel Barreto
- Applied Physiology and Nutrition Research Group, School of Physical Education and Sport, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, SP, Brazil
| | - Felipe Miguel Marticorena
- Applied Physiology and Nutrition Research Group, School of Physical Education and Sport, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, SP, Brazil
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Ruiz-Fernández I, Valadés D, Dominguez R, Ferragut C, Pérez-López A. Load and muscle group size influence the ergogenic effect of acute caffeine intake in muscular strength, power and endurance. Eur J Nutr 2023; 62:1783-1794. [PMID: 36840816 DOI: 10.1007/s00394-023-03109-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 01/31/2023] [Indexed: 02/26/2023]
Abstract
INTRODUCTION Although acute caffeine intake seems to improve muscular strength-power-endurance performance, there is scarce evidence evaluating upper vs lower-body exercises at different loads. Thus, this study aimed to examine the effects of acute caffeine intake on upper and lower-body muscular strength, power and endurance performance at different loads. METHODS Twenty resistance-trained athletes (male/female: 10/10; age: 23 ± 4 years; body mass: 70.6 ± 15.1) participated in a double-blind, placebo-controlled, cross-over and randomized study. Participants were provided with either 3 mg/kg of body mass of caffeine or maltodextrin (placebo). Sixty minutes after ingestion, they performed muscular strength and power assessment for bench press and back squat exercise at 25%, 50%, 75% and 90% 1-repetition-maximum (1RM), performing 3, 2, 1 and 1 repetitions respectively, followed by muscular endurance assessment for both exercises at 65% and 85% 1RM performing until task failure. Isometric handgrip, isometric mid-thigh pull and vertical jump tests were also performed. RESULTS In muscular strength and power, compared to placebo, caffeine improved mean velocity (P = 0.045; pη2 = 0.101), mean power (P = 0.049; pη2 = 0.189) and rate of force development (RFD, P = 0.032; pη2 = 0.216), particularly in back squat exercise at 75% and 90% 1RM where mean velocity increased by 5-7% (P = 0.48-0.038; g = 0.348-1.413), mean power by 6-8% (P = 0.050-0.032; g = 0.547-0.818) and RFD by 17-97% (P = 0.042-0.046; g = 1.436-1.196). No differences were found in bench press exercise. In muscular endurance, caffeine improved the number of repetitions in all exercises and loads (P = 0.003; pη2 = 0.206), but only in back squat exercise at 85% 1RM, caffeine increased mean and peak velocity (8-9%, P = 0.006-0.004; g = 2.029-2.075), mean and peak power (10-13%, P = 0.006-0.003; g = 0.888-1.151) and force peak (3%, P = 0.009; g = 0.247). CONCLUSIONS Acute caffeine intake (3 mg/kg) improved muscular strength, power and endurance performance, revealing a more pronounced effect at high-loads (≥ 75% 1RM) and in lower-body (back squat) than in upper-body exercise (bench press) according to muscle group size.
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Affiliation(s)
- Iván Ruiz-Fernández
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Ctra. Madrid-Barcelona km 33,600, 28871, Alcalá de Henares, Spain
| | - David Valadés
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Ctra. Madrid-Barcelona km 33,600, 28871, Alcalá de Henares, Spain
| | - Raúl Dominguez
- Departamento de Motricidad Humana y Rendimiento Deportivo, Universidad de Sevilla, Seville, Spain
| | - Carmen Ferragut
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Ctra. Madrid-Barcelona km 33,600, 28871, Alcalá de Henares, Spain.
| | - Alberto Pérez-López
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Ctra. Madrid-Barcelona km 33,600, 28871, Alcalá de Henares, Spain
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13
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López-Torres O, Rodríguez-Longobardo C, Capel-Escoriza R, Fernández-Elías VE. Ergogenic Aids to Improve Physical Performance in Female Athletes: A Systematic Review with Meta-Analysis. Nutrients 2022; 15:nu15010081. [PMID: 36615738 PMCID: PMC9823656 DOI: 10.3390/nu15010081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/17/2022] [Accepted: 12/20/2022] [Indexed: 12/29/2022] Open
Abstract
Most intervention studies investigating the effects of ergogenic aids (EAs) on sports performance have been carried out in the male population. Thus, the aim of this systematic review and meta-analysis was to summarize the effects in the existing literature of EAs used by female athletes on performance. A literature research was conducted, and a descriptive analysis of the articles included in the systematic review was carried out. Meta-analyses could be performed on 32 of the included articles, evaluating performance in strength, sprint, and cardiovascular capacity. A random-effects model and the standardized mean differences (SMD) ± 95% confidence intervals (CI) were reported. The results showed that caffeine helped to improve jumping performance, isometric strength values, and the number of repetitions until failure. Caffeine and sodium phosphate helped to improve sprint performance. Aerobic tests could be improved with the use of taurine, caffeine, and beta-alanine. No conclusive effects of beetroot juice, polyphenols, or creatine in improving aerobic performance were shown. In terms of anaerobic variables, both caffeine and sodium phosphate could help to improve repeated sprint ability. More studies are needed in female athletes that measure the effects of different EAs on sports performance, such as beetroot juice, beta-alanine or sodium phosphate, as the studies to date are scarce and there are many types of EA that need to be further considered in this population, such as creatine and taurine.
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Affiliation(s)
- Olga López-Torres
- Faculty of Sport Sciences, Universidad Europea de Madrid, 28670 Madrid, Spain
| | - Celia Rodríguez-Longobardo
- Social Sciences of Physical Activity, Sport and Leisure Department, Faculty of Physical Activity and Sport Sciences, Universidad Politécnica de Madrid, 28040 Madrid, Spain
- Correspondence:
| | - Raquel Capel-Escoriza
- Faculty of Sport Sciences, Universidad Europea de Madrid, 28670 Madrid, Spain
- Raquel Wellness Instituto de Nutrición y Salud, 28050 Madrid, Spain
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Berjisian E, Naderi A, Mojtahedi S, Grgic J, Ghahramani MH, Karayigit R, Forbes JL, Amaro-Gahete FJ, Forbes SC. Are Caffeine's Effects on Resistance Exercise and Jumping Performance Moderated by Training Status? Nutrients 2022; 14:nu14224840. [PMID: 36432526 PMCID: PMC9692585 DOI: 10.3390/nu14224840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/10/2022] [Accepted: 11/13/2022] [Indexed: 11/17/2022] Open
Abstract
This study aimed to explore if the effects of caffeine intake on resistance exercise and jumping performance are moderated by training status. We included ten resistance-trained and ten recreationally active males in a randomized, double-blind, crossover study. Participants were categorized into groups according to their resistance to training experience and muscular strength levels. Exercise performance outcomes included weight lifted and mean velocity during a one-repetition maximum (1RM) bench press and squat; repetitions were performed to muscular failure in the same exercises with 70% of 1RM and countermovement jump (CMJ) height. Exercise performance was evaluated on three occasions, following no substance ingestion (control), caffeine (6 mg/kg), and placebo. There was a main effect on the condition for all the performance outcomes (all p ≤ 0.02), except for the 1RM squat mean velocity (p = 0.157) and 1RM bench press mean velocity (p = 0.719). For weight lifted in the 1RM bench press, there was a significant difference when comparing the caffeine vs. control, caffeine vs. placebo, and placebo vs. control. For weight lifted in the 1RM squat, a significant difference was found when comparing the caffeine vs. control. For muscular endurance outcomes and jump height, a significant difference was found when caffeine was compared to the control or placebo. Effect sizes were trivial for muscular strength (Hedges' g: 0.04-0.12), small for the jump height (Hedges' g: 0.43-0.46), and large for muscular endurance (Hedges' g: 0.89-1.41). Despite these ergogenic effects, there was no significant training status × caffeine interaction in any of the analyzed outcomes. In summary, caffeine ingestion is ergogenic for muscular strength, endurance, and jump height. These effects are likely to be of a similar magnitude in resistance-trained and recreationally active men.
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Affiliation(s)
- Erfan Berjisian
- Department of Exercise Physiology, Faculty of Physical Education and Sport Sciences, Tehran University, Tehran 1417935840, Iran
| | - Alireza Naderi
- Department of Exercise Physiology, Borujerd Branch, Islamic Azad University, Borujerd 6915136111, Iran
| | - Shima Mojtahedi
- Department of Exercise Physiology, Faculty of Physical Education and Sport Sciences, Tehran University, Tehran 1417935840, Iran
- Correspondence: (S.M.); (S.C.F.)
| | - Jozo Grgic
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3011, Australia
| | - Mohammad Hossein Ghahramani
- Physical Education and Sport Sciences Department, Faculty of Humanities, Tarbiat Modares University, Tehran 1411713116, Iran
| | - Raci Karayigit
- Faculty of Sport Sciences, Ankara University, Gölbaşı, Ankara 06830, Turkey
| | - Jennifer L. Forbes
- Department of Physical Education Studies, Brandon University, Brandon, MB R7A 6A9, Canada
| | - Francisco J. Amaro-Gahete
- PROmoting FITness and Health through Physical Activity Research Group (PROFITH), Department of Physical and Sports Education, Faculty of Sports Science, University of Granada, 18011 Granada, Spain
- Department of Physiology, Faculty of Medicine, EFFECTS-262 Research Group, University of Granada, 18016 Granada, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Scott C. Forbes
- Department of Physical Education Studies, Brandon University, Brandon, MB R7A 6A9, Canada
- Correspondence: (S.M.); (S.C.F.)
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15
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Karayigit R, Ramirez-Campillo R, Yasli BC, Gabrys T, Benesova D, Esen O. High Dose of Acute Normobaric Hypoxia Does Not Adversely Affect Sprint Interval Training, Cognitive Performance and Heart Rate Variability in Males and Females. BIOLOGY 2022; 11:biology11101463. [PMID: 36290367 PMCID: PMC9598265 DOI: 10.3390/biology11101463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/01/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022]
Abstract
Although preliminary studies suggested sex-related differences in physiological responses to hypoxia, the effects of sex on sprint interval training (SIT) performance in different degrees of hypoxia are largely lacking. The aim of this study was to examine the acute effect of different doses of normobaric hypoxia on SIT performance as well as heart rate variability (HRV) and cognitive performance (CP) in amateur-trained team sport players by comparing potential sex differences. In a randomized, double-blind, crossover design, 26 (13 females) amateur team-sport (football, basketball, handball, rugby) players completed acute SIT (6 × 15 s all-out sprints, separated with 2 min active recovery, against a load equivalent to 9% of body weight) on a cycle ergometer, in one of four conditions: (I) normoxia without a mask (FiO2: 20.9%) (CON); (II) normoxia with a mask (FiO2: 20.9%) (NOR); (III) moderate hypoxia (FiO2: 15.4%) with mask (MHYP); and (IV) high hypoxia (FiO2: 13.4%) with mask (HHYP). Peak (PPO) and mean power output (MPO), HRV, heart rate (HR), CP, capillary lactate (BLa), and ratings of perceived exertion (RPE) pre- and post-SIT were compared between CON, NOR, MHYP and HHYP. There were no significant differences found between trials for PPO (p = 0.55), MPO (p = 0.44), RPE (p = 0.39), HR (p = 0.49), HRV (p > 0.05) and CP (response accuracy: p = 0.92; reaction time: p = 0.24). The changes in MP, PP, RPE, HR, CP and HRV were similar between men and women (all p > 0.05). While BLa was similar (p = 0.10) between MHYP and HHYP trials, it was greater compared to CON (p = 0.01) and NOR (p = 0.01), without a sex-effect. In conclusion, compared to normoxia, hypoxia, and wearing a mask, have no effect on SIT acute responses (other than lactate), including PP, MP, RPE, CP, HR, and cardiac autonomic modulation either in men or women.
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Affiliation(s)
- Raci Karayigit
- Faculty of Sport Sciences, Ankara University, Gölbaşı, Ankara 06830, Turkey
- Correspondence: ; Tel.: +90-312-600-0100
| | - Rodrigo Ramirez-Campillo
- School of Physical Therapy, Faculty of Rehabilitation Sciences, Exercise and Rehabilitation Sciences Institute, Universidad Andres Bello, Santiago 7591538, Chile
| | - Burak Caglar Yasli
- Department of Physical Education and Sports, Iğdır University, Iğdır 76000, Turkey
| | - Tomasz Gabrys
- Department of Physical Education and Sport, Faculty of Education, University of West Bohemia, 30100 Pilsen, Czech Republic
| | - Daniela Benesova
- Department of Physical Education and Sport, Faculty of Education, University of West Bohemia, 30100 Pilsen, Czech Republic
| | - Ozcan Esen
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK
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16
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López-Seoane J, Buitrago-Morales M, Jiménez SL, Del Coso J, Pareja-Galeano H. Synergy of carbohydrate and caffeine ingestion on physical performance and metabolic responses to exercise: A systematic review with meta-analysis. Crit Rev Food Sci Nutr 2022; 64:2941-2959. [PMID: 36178302 DOI: 10.1080/10408398.2022.2128298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Carbohydrates (CHO) and caffeine (CAF) are two ergogenic aids commonly used among athletes to enhance performance. However, there is some controversy as to whether the concurrent intake of both supplements might result in an additive and synergistic improvement in exercise performance. The aim of this systematic review and meta-analysis was to determine the effect of adding CAF to a protocol of CHO ingestion, compared with the intake of each ergogenic aid alone and with placebo, on exercise performance and metabolic responses in healthy young physically active adults. This study was conducted according to PRISMA 2020 guidelines. The PubMed, Web of Science, Medline Complete, CINAHL, SPORTDiscus and CENTRAL databases were searched including randomized controlled trials (RCT) that were at least single blind. The risk of bias assessment was performed using the Cochrane Risk-of-Bias tool 2. Meta-analysis were performed on performance variables and rating of perceived exertion (RPE) using the random-effects model. Thirteen RCT with 128 participants (117 men and 11 women) were included in this study. The ingestion of CAF and CHO reduced sprint time during repeated sprint protocols in comparison with CHO isolated ingestion (SMD: -0.45; 95% CI: -0.85, -0.05) while there was a tendency for a reduction in the time employed during time trials (SMD: -0.36; 95% CI: -0.77, 0.05). The RPE tended to be lower with CAF and CHO compared with CHO isolated ingestion during steady-state exercise (SMD: -0.43; 95% CI: -0.91, 0.05) with no differences between conditions in performance trials (SMD: -0.05, 95% CI: -0.39, 0.29). Although most of the studies showed higher values of blood glucose when CHO was co-ingested with CAF compared with PLA, only two studies observed higher values with CHO and CAF co-ingestion with respect to the isolated intake of CHO. One study observed greater fat oxidation and lower glycogen use when CAF was added to CHO. In terms of cortisol levels, one study showed an increase in cortisol levels when CAF was co-ingested with CHO compared with PLA. In summary, concurrent CHO and CAF intake may produce an additive ergogenic effect respect of the isolated ingestion of CHO. This additive effect was present when CHO was provided by a 6-9% of CHO solution (maltodextrin/dextrin + fructose) and CAF is administered in a dose of 4-6.5 mg/kg.
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Affiliation(s)
- Jaime López-Seoane
- ImFINE Research Group, Department of Health and Human Performance, Faculty of Physical Activity and Sport Sciences-INEF, Universidad Politécnica de Madrid, Madrid, Spain
- Red Española de Investigación en Ejercicio Físico y Salud (EXERNET), Madrid, Spain
| | - Marta Buitrago-Morales
- Faculty of Sports Sciences and Physiotherapy, Universidad Europea de Madrid, Madrid, Spain
| | - Sergio L Jiménez
- Centre for Sport Studies, Universidad Rey Juan Carlos, Madrid, Spain
| | - Juan Del Coso
- Centre for Sport Studies, Universidad Rey Juan Carlos, Madrid, Spain
| | - Helios Pareja-Galeano
- Department of Physical Education, Sport and Human Movement, Universidad Autónoma de Madrid, Madrid, Spain
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17
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Can I Have My Coffee and Drink It? A Systematic Review and Meta-analysis to Determine Whether Habitual Caffeine Consumption Affects the Ergogenic Effect of Caffeine. Sports Med 2022; 52:2209-2220. [PMID: 35536449 DOI: 10.1007/s40279-022-01685-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2022] [Indexed: 01/04/2023]
Abstract
OBJECTIVE The aim was to quantify the proportion of the literature on caffeine supplementation that reports habitual caffeine consumption, and determine the influence of habitual consumption on the acute exercise response to caffeine supplementation, using a systematic review and meta-analytic approach. METHODS Three databases were searched, and articles screened according to inclusion/exclusion criteria. Three-level meta-analyses and meta-regression models were used to investigate the influence of habitual caffeine consumption on caffeine's overall ergogenic effect and within different exercise types (endurance, power, strength), in men and women, and in trained and untrained individuals. Sub-analyses were performed according to the following: acute relative dose (< 3, 3-6, > 6 mg/kg body mass [BM]); whether the acute caffeine dose provided was lower or higher than the mean daily caffeine dose; and the caffeine withdrawal period prior to the intervention (< 24, 24-48, > 48 h). RESULTS Sixty caffeine studies included sufficient information on habitual consumption to be included in the meta-analysis. A positive overall effect of caffeine was shown in comparison to placebo (standard mean difference [SMD] = 0.25, 95% confidence interval [CI] 0.20-0.30; p < 0.001) with no influence of relative habitual caffeine consumption (p = 0.59). Subgroup analyses showed a significant ergogenic effect when the caffeine dose was < 3 mg/kg BM (SMD = 0.26, 95% CI 0.12-0.40; p = 0.003) and 3-6 mg/kg BM (SMD = 0.26, 95% CI 0.21-0.32; p < 0.0001), but not > 6 mg/kg BM (SMD = 0.11, 95% CI - 0.07 to 0.30; p = 0.23); when the dose was both higher (SMD = 0.26, 95% CI 0.20-0.31; p < 0.001) and lower (SMD = 0.21, 95% CI 0.06-0.36; p = 0.006) than the habitual caffeine dose; and when withdrawal was < 24 h, 24-48 h, and > 48 h. Caffeine was effective for endurance, power, and strength exercise, with no influence (all p ≥ 0.23) of relative habitual caffeine consumption within exercise types. Habitual caffeine consumption did not modify the ergogenic effect of caffeine in male, female, trained or untrained individuals. CONCLUSION Habitual caffeine consumption does not appear to influence the acute ergogenic effect of caffeine.
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18
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Porto AA, Benjamim CJR, Gonzaga LA, Luciano de Almeida M, Bueno Júnior CR, Garner DM, Valenti VE. Caffeine intake and its influences on heart rate variability recovery in healthy active adults after exercise: A systematic review and meta-analysis. Nutr Metab Cardiovasc Dis 2022; 32:1071-1082. [PMID: 35272883 DOI: 10.1016/j.numecd.2022.01.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 11/19/2022]
Abstract
AIMS Results regarding the effects of caffeine (CAF) intake on the autonomic control of heart rate recovery exercise remain inconclusive. Thus far, no study has used effect measures to pool the results of different experiments. We aim to assess the acute effect of CAF intake before exercise on the recovery of heart rate variability (HRV) after exercise through a systematic review and meta-analysis. DATA SYNTHESIS Randomized controlled clinical trials were included; sample composed of physically active or trained adults; CAF should be offered/ingested before exercise, with dosage between 100 and 400 mg or between 2 and 6 mg/kg and administration/ingestion route analogous in the protocols; studies required to present results of HRV indices before and after exercise. Bias risk analysis and meta-analysis were performed. Twelve studies were included in the qualitative synthesis and five studies were encompassed in the quantitative synthesis (meta-analysis). For the Root-mean-square standard deviation (RMSSD) index we revealed p = 0.67, Total 95% confidence interval (95% CI) ranged from -0.45 to 0.29, and 66.7% for heterogeneity between groups were reported. Concerning the High Frequency (HF) index, we observed p = 0.22, Total 95% CI that ranged from -0.34 to 0.30, and 44% for heterogeneity between groups. CONCLUSIONS CAF intake did not affect heart rate variability recovery after exercise.
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Affiliation(s)
- Andrey Alves Porto
- Department of Physical Therapy, Faculty of Sciences and Technologies, UNESP, Presidente Prudente, Brazil; Autonomic Nervous System Center, UNESP, Marilia, SP, Brazil
| | - Cicero Jonas R Benjamim
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirão Preto, Brazil
| | - Luana Almeida Gonzaga
- Department of Physical Therapy, Faculty of Sciences and Technologies, UNESP, Presidente Prudente, Brazil; Autonomic Nervous System Center, UNESP, Marilia, SP, Brazil
| | | | - Carlos Roberto Bueno Júnior
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirão Preto, Brazil; School of Physical Education of Ribeirão Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | - David M Garner
- Oxford Brookes University, Headington Campus, Gipsy Lane, Oxford, OX3 0BP, United Kingdom; Autonomic Nervous System Center, UNESP, Marilia, SP, Brazil
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19
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Automated Detection of Caffeinated Coffee-Induced Short-Term Effects on ECG Signals Using EMD, DWT, and WPD. Nutrients 2022; 14:nu14040885. [PMID: 35215531 PMCID: PMC8875083 DOI: 10.3390/nu14040885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 01/27/2023] Open
Abstract
The effect of coffee (caffeinated) on electro-cardiac activity is not yet sufficiently researched. In the current study, the occurrence of coffee-induced short-term changes in electrocardiogram (ECG) signals was examined. Further, a machine learning model that can efficiently detect coffee-induced alterations in cardiac activity is proposed. The ECG signals were decomposed using three different joint time–frequency decomposition methods: empirical mode decomposition, discrete wavelet transforms, and wavelet packet decomposition with varying decomposition parameters. Various statistical and entropy-based features were computed from the decomposed coefficients. The statistical significance of these features was computed using Wilcoxon’s signed-rank (WSR) test for significance testing. The results of the WSR tests infer a significant change in many of these parameters after the consumption of coffee (caffeinated). Further, the analysis of the frequency bands of the decomposed coefficients reveals that most of the significant change was localized in the lower frequency band (<22.5 Hz). Herein, the performance of nine machine learning models is compared and a gradient-boosted tree classifier is proposed as the best model. The results suggest that the gradient-boosted tree (GBT) model that was developed using a db2 mother wavelet at level 2 decomposition shows the highest mean classification accuracy of 78%. The outcome of the current study will open up new possibilities in detecting the effects of drugs, various food products, and alcohol on cardiac functionality.
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20
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Srivastava B, Sen S, Bhakta S, Sen K. Effect of caffeine on the possible amelioration of diabetic neuropathy: A spectroscopic study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 264:120322. [PMID: 34509062 DOI: 10.1016/j.saa.2021.120322] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/07/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
IMPORTANCE One of the consequential and alarming complications of diabetes mellitus is diabetic neuropathy (DN). DN is assured to be caused chiefly by excess sorbitol levels in the body. The harmful consequences of DN alike peripheral nerve damage with extremity ulcers may be dodged with timely detection and treatment. The therapeutic methods for DN are scarce and expensive. Therefore economic and user friendly methodologies to prevent acquiring the disease need proper attention. OBJECTIVE The present research has been conducted (1) to analyse the levels of sorbitol in diabetic blood samples and compare them with non-diabetic ones and (2) to study the reduction in sorbitol levels upon addition of an important biochemical compounds caffeine in both sample groups. RESEARCH DESIGN, SETTING, PARTICIPANTS AND METHOD Sorbitol-caffeine interaction analysis of blood samples of 16 patients with type 2 diabetes from KPC Medical College, Kolkata, India was made. The spectroscopic analysis and their interpretations were compared with 16 healthy subjects. MAIN OUTCOMES AND MEASURES Present work describes that caffeine can be helpful in reducing the sorbitol level in diabetics, so the chances of development and progression of diabetic neuropathy can be controlled with the introduction of caffeine. RESULTS A total number of 32 blood samples of patients (aged 35-70 years); mean age ranges were 52.06 ± 2.68 and 53.50 ± 2.66 years for non-diabetic and diabetic ones respectively, glucose and sorbitol screening examination were done by enzymatic methodologies where concentrations were assessed by means of either absorption or fluorescence spectroscopy. The calibration range was 18.2-1119.3 mg/dL (Linear regression analysis r2 = 0.996). The sensitivity of this screening program in detecting DN with the healthy adults has been inquired and found efficient. Results of fasting insulin analyses have also been analysed for HOMA-IR (homeostasis model assessment - insulin resistance) and HOMA-B (homeostasis model assessment - pancreatic β cell function) values. Statistical significance of the results in non-diabetic and diabetic groups were performed and found to be statistically significant. CONCLUSIONS We have defined the relationship between blood glucose level, insulin level, sorbitol and caffeine in human body and utilized them in the plausible remediation of DN.
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Affiliation(s)
- Bhavya Srivastava
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| | - Souvik Sen
- KPC Medical College and Hospital, 1F, Raja Subodh Chandra Mullick Road, Jadavpur, Kolkata 700032, India
| | - Santanu Bhakta
- KPC Medical College and Hospital, 1F, Raja Subodh Chandra Mullick Road, Jadavpur, Kolkata 700032, India
| | - Kamalika Sen
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
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21
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Oliver LS, Sullivan JP, Russell S, Peake JM, Nicholson M, McNulty C, Kelly VG. Effects of Nutritional Interventions on Accuracy and Reaction Time with Relevance to Mental Fatigue in Sporting, Military, and Aerospace Populations: A Systematic Review and Meta-Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:307. [PMID: 35010566 PMCID: PMC8744602 DOI: 10.3390/ijerph19010307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 01/10/2023]
Abstract
Background: Research in sport, military, and aerospace populations has shown that mental fatigue may impair cognitive performance. The effect of nutritional interventions that may mitigate such negative effects has been investigated. This systematic review and meta-analysis aimed to quantify the effects of nutritional interventions on cognitive domains often measured in mental fatigue research. Methods: A systematic search for articles was conducted using key terms relevant to mental fatigue in sport, military, and aerospace populations. Two reviewers screened 11,495 abstracts and 125 full texts. A meta-analysis was conducted whereby effect sizes were calculated using subgroups for nutritional intervention and cognitive domains. Results: Fourteen studies were included in the meta-analysis. The consumption of energy drinks was found to have a small positive effect on reaction time, whilst the use of beta-alanine, carbohydrate, and caffeine had no effect. Carbohydrate and caffeine use had no effect on accuracy. Conclusions: The results of this meta-analysis suggest that consuming energy drinks may improve reaction time. The lack of effect observed for other nutritional interventions is likely due to differences in the type, timing, dosage, and form of administration. More rigorous randomized controlled trials related to the effect of nutrition interventions before, during, and after induced mental fatigue are required.
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Affiliation(s)
- Liam S. Oliver
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia; (L.S.O.); (J.M.P.); (M.N.); (C.M.)
| | | | - Suzanna Russell
- School of Behavioural and Health Sciences, Australian Catholic University, Brisbane, QLD 4014, Australia;
| | - Jonathan M. Peake
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia; (L.S.O.); (J.M.P.); (M.N.); (C.M.)
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - Mitchell Nicholson
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia; (L.S.O.); (J.M.P.); (M.N.); (C.M.)
| | - Craig McNulty
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia; (L.S.O.); (J.M.P.); (M.N.); (C.M.)
| | - Vincent G. Kelly
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia; (L.S.O.); (J.M.P.); (M.N.); (C.M.)
- School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD 4059, Australia
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22
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Marinho AH, Gonçalves JS, Araújo PK, Lima-Silva AE, Ataide-Silva T, de Araujo GG. Effects of creatine and caffeine ingestion in combination on exercise performance: A systematic review. Crit Rev Food Sci Nutr 2021:1-14. [PMID: 34845944 DOI: 10.1080/10408398.2021.2007470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Creatine (CRE) and caffeine (CAF) have been used as ergogenic aids to improve exercise performance. The present study reviewed the current evidence supporting the additional use of CAF intake during or after the CRE loading on exercise performance. The search was carried out in eight databases, with the methodological quality of the studies assessed via the QualSyst tool. From ten studies that met the criteria for inclusion, six had strong, three moderate, and one weak methodological quality. CAF was ingested ∼1 h before the performance trial (5-7 mg.kg-1) after a CRE loading period (5-6 days with 0.3 g.kg-1.d-1) in five studies, with the combination CAF + CRE providing additional ergogenic effect compared to CRE alone in three of these studies. Furthermore, CAF was ingested daily during the CRE loading protocol in five studies, with CAF showing additive benefits compared to CRE alone only in one study (3 g.d-1 of CRE during 3 days + 6 mg.kg-1 of CAF for 3 days). The combination CAF + CRE seems to provide additional benefits to exercise performance when CAF is acutely ingested after a CRE loading. There is, however, no apparent benefit in ingesting CAF during a CRE loading period.
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Affiliation(s)
- Alisson H Marinho
- Post Graduate Nutrition Program, Faculty of Nutrition, Federal University of Alagoas, Maceió, Brazil.,Laboratory of Applied Sports Science, Institute of Physical Education and Sports, Federal University of Alagoas, Maceió, Brazil
| | | | - Palloma K Araújo
- Post Graduate Nutrition Program, Faculty of Nutrition, Federal University of Alagoas, Maceió, Brazil.,Faculty of Nutrition, Federal University of Alagoas, Maceió, Brazil
| | - Adriano E Lima-Silva
- Human Performance Research Group, Federal University of Technology Parana, Curitiba, Brazil
| | - Thays Ataide-Silva
- Post Graduate Nutrition Program, Faculty of Nutrition, Federal University of Alagoas, Maceió, Brazil.,Faculty of Nutrition, Federal University of Alagoas, Maceió, Brazil
| | - Gustavo G de Araujo
- Post Graduate Nutrition Program, Faculty of Nutrition, Federal University of Alagoas, Maceió, Brazil.,Laboratory of Applied Sports Science, Institute of Physical Education and Sports, Federal University of Alagoas, Maceió, Brazil
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Karayigit R, Koz M, Sánchez-Gómez A, Naderi A, Yildirim UC, Domínguez R, Gur F. High Dose of Caffeine Mouth Rinse Increases Resistance Training Performance in Men. Nutrients 2021; 13:3800. [PMID: 34836058 PMCID: PMC8617760 DOI: 10.3390/nu13113800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 01/18/2023] Open
Abstract
Caffeine mouth rinsing (CMR) has been shown to enhance exercise performance. However, no studies have analyzed the effects of different dosages of CMR on muscular performance. Therefore, the purpose of this study was to examine the effects of different dosages of CMR on strength (bench press 1 repetition maximum (1-RM)) and muscular endurance (60% of 1-RM repetitions to failure) in resistance-trained males. Fourteen resistance-trained males (age: 23 ± 2 years, height: 179 ± 3 cm, body mass: 83 ± 4 kg, BMI: 17 ± 2 kg/m2) completed four conditions in random order. The four conditions consisted of a mouth rinse with 25 mL solutions containing either 1% (250 mg) of CMR (low dose of CMR: LCMR), 2% (500 mg) of CMR (moderate dose of CMR: MCMR), 3% (750 mg) of CMR (high dose of CMR: HCMR) and sweetened water (placebo: PLA) for 5 s prior to a bench press strength and muscular endurance test. Maximal strength, muscular endurance, heart rate (HR) and ratings of perceived exertion (RPE) were recorded for each condition. There were no significant differences in strength (p = 0.30) and HR (p = 0.83) between conditions. HCMR significantly increased muscular endurance performance (p = 0.01) and decreased RPE values (p = 0.01). In conclusion, CMR did not affect bench press 1-RM strength performance, but muscular endurance responses to CMR seems to be dose-dependent.
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Affiliation(s)
- Raci Karayigit
- Faculty of Sport Sciences, Ankara University, Gölbaşı, Ankara 06830, Turkey; (M.K.); (U.C.Y.)
| | - Mitat Koz
- Faculty of Sport Sciences, Ankara University, Gölbaşı, Ankara 06830, Turkey; (M.K.); (U.C.Y.)
| | - Angela Sánchez-Gómez
- Department of Nursing Pharmacology and Physiotherapy, Faculty of Medicine and Nursing, University of Córdoba, 14000 Córdoba, Spain;
| | - Alireza Naderi
- Department of Sport Physiology, Boroujerd Branch, Islamic Azad University, Boroujerd 6915136111, Iran;
| | - Ulas Can Yildirim
- Faculty of Sport Sciences, Ankara University, Gölbaşı, Ankara 06830, Turkey; (M.K.); (U.C.Y.)
| | - Raúl Domínguez
- Departamento de Motricidad Humana y Rendimiento Deportivo, Universidad de Sevilla, 41013 Sevilla, Spain
- Studies Research Group in Neuromuscular Responses (GEPREN), University of Lavras, Lavras 37200-000, Brazil
| | - Fatih Gur
- Faculty of Sport Science, Pamukkale University, Pamukkale, Denizli 20000, Turkey;
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Does Acute Caffeine Supplementation Improve Physical Performance in Female Team-Sport Athletes? Evidence from a Systematic Review and Meta-Analysis. Nutrients 2021; 13:nu13103663. [PMID: 34684665 PMCID: PMC8538965 DOI: 10.3390/nu13103663] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/17/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022] Open
Abstract
Introduction: Recent original research and meta-analyses suggest that acute caffeine supplementation improves exercise performance in team-sport athletes (TSA). Nonetheless, most of the studies testing the effects of caffeine on TSA included samples of male athletes, and there is no meta-analysis of the performance-enhancing effects of caffeine on female TSA. The aim of the present study was to synthesize the existing literature regarding the effect of caffeine supplementation on physical performance in adult female TSA. Methods: A search was performed in Pubmed/Medline, SPORTDiscus and Scopus. The search was performed from the inception of indexing until 1 September 2021. Crossover randomized controlled trials (RCT) assessing the effects of oral caffeine intake on several aspects of performance in female TSA were selected. The methodological quality and risk of bias were assessed for individual studies using the Physiotherapy Evidence Database scale (PEDro) and the RoB 2 tool. A random-effects meta-analysis of standardized mean differences (SMD) was performed for several performance variables. Results: The search retrieved 18 articles that fulfilled the inclusion/exclusion criteria. Overall, most of the studies were of excellent quality with a low risk of bias. The meta-analysis results showed that caffeine increased performance in specific team-sport skills (SMD: 0.384, 95% confidence interval (CI): 0.077–0.691), countermovement jump (SMD: 0.208, CI: 0.079–0.337), total body impacts (SMD: 0.488; 95% CI: 0.050, 0.927) and handgrip strength (SMD: 0.395, CI: 0.126–0.665). No effects were found on the ratings of perceived exertion, squat jumps, agility, repeated sprint ability or agility tests performed after fatigue. Conclusions: The results of the meta-analysis revealed that acute caffeine intake was effective in increasing some aspects of team-sports performance in women athletes. Hence, caffeine could be considered as a supplementation strategy for female athletes competing in team sports.
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Jones L, Johnstone I, Day C, Le Marquer S, Hulton AT. The Dose-Effects of Caffeine on Lower Body Maximal Strength, Muscular Endurance, and Rating of Perceived Exertion in Strength-Trained Females. Nutrients 2021; 13:3342. [PMID: 34684343 PMCID: PMC8539274 DOI: 10.3390/nu13103342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/21/2021] [Accepted: 09/21/2021] [Indexed: 01/22/2023] Open
Abstract
Caffeine supplementation has shown to be an effective ergogenic aid enhancing athletic performance, although limited research within female populations exists. Therefore, the aim of the investigation was to assess the effect of pre-exercise caffeine supplementation on strength performance and muscular endurance in strength-trained females. In a double-blind, randomised, counterbalanced design, fourteen strength-trained females using hormonal contraception consumed either 3 or 6 mg·kg-1 BM of caffeine or placebo (PLA). Following supplementation, participants performed a one-repetition maximum (1RM) leg press and repetitions to failure (RF) at 60% of their 1RM. During the RF test, rating of perceived exertion (RPE) was recorded every five repetitions and total volume (TV) lifted was calculated. Repeated measures ANOVA revealed that RF (p = 0.010) and TV (p = 0.012) attained significance, with pairwise comparisons indicating a significant difference between 3 mg·kg-1 BM and placebo for RF (p = 0.014), with an effect size of 0.56, and for 6 mg·kg-1 BM (p = 0.036) compared to the placebo, with an effect size of 0.65. No further significance was observed for 1RM or for RPE, and no difference was observed between caffeine trials. Although no impact on lower body muscular strength was observed, doses of 3 and 6 mg·kg-1 BM of caffeine improved lower body muscular endurance in resistance-trained females, which may have a practical application for enhancing resistance training stimuli and improving competitive performance.
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Affiliation(s)
| | | | | | | | - Andrew T. Hulton
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK; (L.J.); (I.J.); (C.D.); (S.L.M.)
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26
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Effects of Caffeine on Resistance Exercise: A Review of Recent Research. Sports Med 2021; 51:2281-2298. [PMID: 34291426 DOI: 10.1007/s40279-021-01521-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2021] [Indexed: 02/06/2023]
Abstract
In the last few years, a plethora of studies have explored the effects of caffeine on resistance exercise, demonstrating that this field of research is growing fast. This review evaluates and summarizes the most recent findings. Given that toxic doses of caffeine are needed to increase skeletal muscle contractility, the binding of caffeine to adenosine receptors is likely the primary mechanism for caffeine's ergogenic effects on resistance exercise. There is convincing evidence that caffeine ingestion is ergogenic for (i) one-repetition maximum, isometric, and isokinetic strength; and (ii) muscular endurance, velocity, and power in different resistance exercises, loads, and set protocols. Furthermore, there is some evidence that caffeine supplementation also may enhance adaptations to resistance training, such as gains in strength and power. Caffeine ingestion is ergogenic for resistance exercise performance in females, and the magnitude of these effects seems to be similar to that observed in men. Habitual caffeine intake and polymorphisms within CYP1A2 and ADORA2A do not seem to modulate caffeine's ergogenic effects on resistance exercise. Consuming lower doses of caffeine (e.g., 2-3 mg/kg) appears to be comparably ergogenic to consuming high doses of caffeine (e.g., 6 mg/kg). Minimal effective doses of caffeine seem to be around 1.5 mg/kg. Alternate caffeine sources such as caffeinated chewing gum, gel, and coffee are also ergogenic for resistance exercise performance. With caffeine capsules, the optimal timing of ingestion seems to be 30-60 min before exercise. Caffeinated chewing gums and gels may enhance resistance exercise performance even when consumed 10 min before exercise. It appears that caffeine improves performance in resistance exercise primarily due to its physiological effects. Nevertheless, a small portion of the ergogenic effect of caffeine seems to be placebo-driven.
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