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Nishikawa T, Hirono T, Holobar A, Kunugi S, Okudaira M, Ohya T, Watanabe K. Acute effects of caffeine or quercetin ingestion on motor unit firing pattern before and after resistance exercise. Eur J Appl Physiol 2024; 124:1645-1658. [PMID: 38193908 DOI: 10.1007/s00421-023-05376-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 11/14/2023] [Indexed: 01/10/2024]
Abstract
The aim of the present study was to investigate the acute effect of caffeine or quercetin ingestion on motor unit firing patterns and muscle contractile properties before and after resistance exercise. High-density surface electromyography (HDs-EMG) during submaximal contractions and electrically elicited torque in knee extensor muscles were measured before (PRE) and 60 min after (POST1) ingestion of caffeine, quercetin glycosides, or placebo, and after resistance exercise (POST2) in ten young males. The Convolution Kernel Compensation technique was used to identify individual motor units of the vastus lateralis muscle for the recorded HDs-EMG. Ingestion of caffeine or quercetin induced significantly greater decreases in recruitment thresholds (RTs) from PRE to POST1 compared with placebo (placebo: 94.8 ± 9.7%, caffeine: 84.5 ± 16.2%, quercetin: 91.9 ± 36.7%), and there were significant negative correlations between the change in RTs (POST1-PRE) and RT at PRE for caffeine (rs = - 0.448, p < 0.001) and quercetin (rs = - 0.415, p = 0.003), but not placebo (rs = - 0.109, p = 0.440). Significant positive correlations between the change in firing rates (POST2-POST1) and RT at PRE were noted with placebo (rs = 0.380, p = 0.005) and quercetin (rs = 0.382, p = 0.007), but not caffeine (rs = 0.069, p = 0.606). No significant differences were observed in electrically elicited torque among the three conditions. These results suggest that caffeine or quercetin ingestion alters motor unit firing patterns after resistance exercise in different threshold-dependent manners in males.
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Affiliation(s)
- Taichi Nishikawa
- Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
| | - Tetsuya Hirono
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Aleš Holobar
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Shun Kunugi
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
- Center for General Education, Aichi Institute of Technology, Toyota, Japan
| | - Masamichi Okudaira
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
| | - Toshiyuki Ohya
- Laboratory for Exercise Physiology and Biomechanics, Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Kohei Watanabe
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan.
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Ferragut C, Gonzalo-Encabo P, López-Samanes Á, Valadés D, Pérez-López A. Effect of Acute Sodium Bicarbonate and Caffeine Coingestion on Repeated-Sprint Performance in Recreationally Trained Individuals: A Randomized Controlled Trial. Int J Sports Physiol Perform 2024; 19:427-434. [PMID: 38335952 DOI: 10.1123/ijspp.2023-0256] [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: 07/08/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 02/12/2024]
Abstract
INTRODUCTION The acute and isolated ingestion of sodium bicarbonate (NaHCO3) and caffeine (CAF) improves performance and delays fatigue in high-intensity tasks. However, it remains to be elucidated if the coingestion of both dietary supplements stimulates a summative ergogenic effect. This study aimed to examine the effect of the acute coingestion of NaHCO3 and CAF on repeated-sprint performance. METHODS Twenty-five trained participants (age: 23.3 [4.0] y; sex [female/male]: 12/13; body mass: 69.6 [12.5] kg) participated in a randomized, double-blind, placebo (PLA) -controlled, crossover study. Participants were assigned to 4 conditions: (1) NaHCO3 + CAF, (2) NaHCO3, (3) CAF, or (4) PLA. Thus, they ingested 0.3 g/kg of NaHCO3, 3 mg/kg of CAF, or PLA. Then, participants performed 4 Wingate tests (Wt), consisting of a 30-second all-out sprint against an individualized resisted load, interspersed by a 1.5-minute rest period between sprints. RESULTS Peak (Wpeak) and mean (Wmean) power output revealed a supplement and sprint interaction effect (P = .009 and P = .049, respectively). Compared with PLA, NaHCO3 + CAF and NaHCO3 increased Wpeak performance in Wt 3 (3%, P = .021) and Wt 4 (4.5%, P = .047), while NaHCO3 supplementation increased mean power performance in Wt 3 (4.2%, P = .001). In Wt 1, CAF increased Wpeak (3.2%, P = .054) and reduced time to Wpeak (-8.5%; P = .008). Plasma lactate showed a supplement plus sprint interaction (P < .001) when NaHCO3 was compared with CAF (13%, P = .031) and PLA (23%, P = .021). CONCLUSION To summarize, although the isolated ingestion of CAF and NaHCO3 improved repeated-sprint performance, the coingestion of both supplements did not stimulate a synergic ergogenic effect.
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Affiliation(s)
- Carmen Ferragut
- Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, Madrid, España
| | - Paola Gonzalo-Encabo
- Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, Madrid, España
| | - Álvaro López-Samanes
- Education, Research Methods and Evaluation Department, Faculty of Human and Social Sciences, Universidad Pontificia Comillas, Madrid, Spain
| | - David Valadés
- Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, Madrid, España
| | - Alberto Pérez-López
- Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, Madrid, España
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Nishikawa T, Hirono T, Takeda R, Okudaira M, Ohya T, Watanabe K. Effects of 7-day quercetin intervention on motor unit activity and muscle contractile properties before and after resistance exercise in young adults randomized controlled trials. Appl Physiol Nutr Metab 2024; 49:447-458. [PMID: 38033306 DOI: 10.1139/apnm-2023-0208] [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] [Indexed: 12/02/2023]
Abstract
We investigated whether the alteration of the motor unit recruitment threshold (MURT) caused by quercetin ingestion intervention for 7 days modifies motor unit activation patterns before and after a single session of resistance exercise. Twenty young male and female adults were divided into two groups: ingestion of placebo (PLA) or quercetin glycosides at 200 mg/day (QUE). High-density surface electromyography during submaximal contractions was measured to assess the motor unit firing rate (MUFR) and MURT of the vastus lateralis muscle before (PRE) and after (POST) resistance exercise (DAY1). The same measurements were repeated after 7 days of placebo or quercetin glycoside ingestion (DAY8). In QUE, MURT decreased more from DAY1-PRE to DAY8-PRE (29.1 ± 9.1 to 27.1 ± 9.5% MVC, p < 0.001) but not in PLA (29.8 ± 10.4 to 28.9 ± 9.7% MVC, p < 0.167). For percentage change in MUFR following resistance exercise, there was a significant interaction (day × group, p < 0.001). The degree of changes in MURT from DAY1-PRE to DAY8-PRE was significantly correlated with the percentage change of MUFR from DAY8-PRE to DAY8-POST in QUE (p = 0.014, r = -0.363) but not in PLA (p = 0.518). The study suggests that 7-day quercetin ingestion alters the motor unit recruitment pattern, and this may induce changes in motor unit firing patterns during a single session of resistance training (Trial registration: UMIN000052255, R000059650).
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Affiliation(s)
- Taichi Nishikawa
- Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Tetsuya Hirono
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Ryosuke Takeda
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Masamichi Okudaira
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Toshiyuki Ohya
- School of Health and Sport Sciences, Chukyo University, Aichi, Japan
| | - Kohei Watanabe
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, Japan
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Watanabe K, Kunugi S, Holobar A. The dose-response relationship of quercetin on the motor unit firing patterns and contractile properties of muscle in men and women. J Int Soc Sports Nutr 2023; 20:2265140. [PMID: 37786989 PMCID: PMC10548840 DOI: 10.1080/15502783.2023.2265140] [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: 03/23/2022] [Accepted: 09/26/2023] [Indexed: 10/04/2023] Open
Abstract
Quercetin is one type of ergogenic aid and its effects on the neuromuscular system have recently attracted interest, but its dose-effect is not yet fully understood. The aim of this study was to examine the effect of different doses of quercetin ingestion on motor unit firing patterns and muscle contractile properties in humans. Thirteen young males and females conducted neuromuscular performance tests before (PRE) and 60 min after (POST) ingestions of 500 or 200 mg of quercetin glycosides (Qg500/Qg200, respectively) or placebo (PLA) on three different days. At PRE and POST, motor unit firing rates were calculated from high-density surface electromyography of the vastus lateralis muscle during 120-s isometric contraction of knee extension at 10% of maximal voluntary contraction. Electrically elicited forces in knee extensor muscles were also measured. After 60 s of voluntary contraction, motor unit firing rates, normalized by the exerted muscle force at POST, were significantly lower at POST than PRE with Qg500 and Qg200 (p < 0.05), but not with PLA (p > 0.05). Changes in motor unit firing rates normalized by the exerted force from PRE to POST were significantly greater with Qg500 than Qg200 at the end of contraction (p < 0.05). Under all three conditions, the electrically elicited force did not significantly change from PRE to POST (p > 0.05). These results suggest that both 500 and 200-mg quercetin ingestions alter motor unit firing patterns, and that quercetin's effect is at least partially dose-dependent.
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Affiliation(s)
- Kohei Watanabe
- Chukyo University, Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Toyota, Japan
| | - Shun Kunugi
- Chukyo University, Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Toyota, Japan
| | - Aleš Holobar
- University of Maribor, Faculty of Electrical Engineering and Computer Science, Maribor, Slovenia
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The Long Way to Establish the Ergogenic Effect of Caffeine on Strength Performance: An Overview Review. Nutrients 2023; 15:nu15051178. [PMID: 36904177 PMCID: PMC10005568 DOI: 10.3390/nu15051178] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
This overview review aimed to describe the evolution of the characteristics of the research on caffeine effects on strength. A total of 189 experimental studies with 3459 participants were included. The median sample size was 15 participants, with an over-representation of men vs. women (79.4 vs. 20.6%). Studies on young participants and elders were scarce (4.2%). Most studies tested a single dose of caffeine (87.3%), while 72.0% used doses adjusted to body mass. Single-dose studies ranged from 1.7 to 7 mg/kg (4.8 ± 1.4 mg/kg), while dose-response studies ranged from 1 to 12 mg/kg. Caffeine was mixed with other substances in 27.0% of studies, although only 10.1% of studies analyzed the caffeine interaction with these substances. Capsules (51.9%) and beverages (41.3%) were the most common forms of caffeine administration. Similar proportions of studies focused on upper (24.9%) or lower body strength 37.6% (37.6% both). Participants' daily intake of caffeine was reported in 68.3% of studies. Overall, the pattern in the study of caffeine's effects on strength performance has been carried out with experiments including 11-15 adults, using a single and moderate dose of caffeine adjusted to participants' body mass in the form of a capsule.
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Tea (Camellia sinensis): A Review of Nutritional Composition, Potential Applications, and Omics Research. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12125874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tea (Camelliasinensis) is the world’s most widely consumed non-alcoholic beverage with essential economic and health benefits since it is an excellent source of polyphenols, catechins, amino acids, flavonoids, carotenoids, vitamins, and polysaccharides. The aim of this review is to summarize the main secondary metabolites in tea plants, and the content and distribution of these compounds in six different types of tea and different organs of tea plant were further investigated. The application of these secondary metabolites on food processing, cosmetics industry, and pharmaceutical industry was reviewed in this study. With the rapid advancements in biotechnology and sequencing technology, omics analyses, including genome, transcriptome, and metabolome, were widely used to detect the main secondary metabolites and their molecular regulatory mechanisms in tea plants. Numerous functional genes and regulatory factors have been discovered, studied, and applied to improve tea plants. Research advances, including secondary metabolites, applications, omics research, and functional gene mining, are comprehensively reviewed here. Further exploration and application trends are briefly described. This review provides a reference for basic and applied research on tea plants.
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Schamne JC, Ressetti JC, Bertuzzi R, Okuno NM, Lima-Silva AE. Acute Caffeine Intake Reduces Perceived Exertion But Not Muscle Pain during Moderate Intensity Cycling Exercise in Women with Fibromyalgia. J Am Coll Nutr 2021; 41:720-727. [PMID: 34383607 DOI: 10.1080/07315724.2021.1958102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Exacerbated perceived exertion and muscle pain responses during exercise might limit physical activity practice in fibromyalgia patients. Thus, nutritional strategies that can reduce perceived exertion and muscle pain during exercise in fibromyalgia patients would be useful. The purpose of this study was to investigate the effects of acute caffeine intake on the perceptions of exertion and muscle pain during a moderate intensity exercise in women with fibromyalgia.Method: Using a randomized, double-blinded, placebo-controlled and crossover experimental design, eleven sedentary women diagnosed with fibromyalgia (age: 44.6 ± 10.5 years; body mass index: 28.5 ± 4.5 kg.m-2) ingested a capsule containing either caffeine (5 mg per kg of body mass) or cellulose (placebo), 60 minutes before performing a 30-minute constant-load cycling exercise, with work rate fixed at 50% of their individual peak workload attained in an incremental exercise test. Ratings of perceived leg muscle pain and perceived exertion were assessed every 5 minutes of exercise.Results: The perceived leg muscle pain was similar (F(1,10) = 1.18, p = 0.30, ŋ2 = 0.11) between caffeine (2.1 ± 1.2 arbitrary units) and placebo conditions (2.2 ± 0.9 arbitrary units). The perceived exertion, however, was on average 8 ± 6% lower (F(1,10) = 12.13; p = 0.006; ŋ2 = 0.55) during exercise in the caffeine condition (12.4 ± 1.3 arbitrary units) than in the placebo condition (13.1 ± 1.1 arbitrary units).Conclusions: These findings indicate that acute caffeine intake could be an attractive strategy to attenuate the exacerbated perceived exertion of fibromyalgia patients during moderate intensity exercise.
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Affiliation(s)
- Julio Cezar Schamne
- Human Performance Research Group, Academic Department of Physical Education, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil.,Department of Physical Education, State University of Ponta Grossa (UEPG), Ponta Grossa, Brazil
| | - Juliana Campos Ressetti
- Department of Physical Education, State University of Ponta Grossa (UEPG), Ponta Grossa, Brazil
| | - Romulo Bertuzzi
- Endurance Performance Research Group (GEDAE-USP), University of São Paulo, São Paulo, Brazil
| | - Nilo Massaru Okuno
- Department of Physical Education, State University of Ponta Grossa (UEPG), Ponta Grossa, Brazil
| | - Adriano Eduardo Lima-Silva
- Human Performance Research Group, Academic Department of Physical Education, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil
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Lima-Silva AE, Cristina-Souza G, Silva-Cavalcante MD, Bertuzzi R, Bishop DJ. Caffeine during High-Intensity Whole-Body Exercise: An Integrative Approach beyond the Central Nervous System. Nutrients 2021; 13:2503. [PMID: 34444663 PMCID: PMC8400708 DOI: 10.3390/nu13082503] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 11/16/2022] Open
Abstract
Caffeine is one of the most consumed ergogenic aids around the world. Many studies support the ergogenic effect of caffeine over a large spectrum of exercise types. While the stimulatory effect of caffeine on the central nervous system is the well-accepted mechanism explaining improvements in exercise performance during high-intensity whole-body exercise, in which other physiological systems such as pulmonary, cardiovascular, and muscular systems are maximally activated, a direct effect of caffeine on such systems cannot be ignored. A better understanding of the effects of caffeine on multiple physiological systems during high-intensity whole-body exercise might help to expand its use in different sporting contexts (e.g., competitions in different environments, such as altitude) or even assist the treatment of some diseases (e.g., chronic obstructive pulmonary disease). In the present narrative review, we explore the potential effects of caffeine on the pulmonary, cardiovascular, and muscular systems, and describe how such alterations may interact and thus contribute to the ergogenic effects of caffeine during high-intensity whole-body exercise. This integrative approach provides insights regarding how caffeine influences endurance performance and may drive further studies exploring its mechanisms of action in a broader perspective.
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Affiliation(s)
- Adriano E. Lima-Silva
- Human Performance Research Group, Federal University of Technology Parana (UTFPR), Curitiba 81310900, PR, Brazil; (A.E.L.-S.); (G.C.-S.)
| | - Gislaine Cristina-Souza
- Human Performance Research Group, Federal University of Technology Parana (UTFPR), Curitiba 81310900, PR, Brazil; (A.E.L.-S.); (G.C.-S.)
- Nutrition and Exercise Research Group, State University of Minas Gerais (UEMG), Passos 37902092, MG, Brazil
| | - Marcos D. Silva-Cavalcante
- Postgraduate Program in Nutrition (PPGNUT), Faculty of Nutrition (FANUT), Federal University of Alagoas (UFAL), Maceio 57072900, AL, Brazil;
| | - Romulo Bertuzzi
- Endurance Sports Research Group (GEDAE-USP), University of São Paulo, Sao Paulo 05508030, SP, Brazil;
| | - David J. Bishop
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC 8001, Australia
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Hostrup M, Cairns SP, Bangsbo J. Muscle Ionic Shifts During Exercise: Implications for Fatigue and Exercise Performance. Compr Physiol 2021; 11:1895-1959. [PMID: 34190344 DOI: 10.1002/cphy.c190024] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Exercise causes major shifts in multiple ions (e.g., K+ , Na+ , H+ , lactate- , Ca2+ , and Cl- ) during muscle activity that contributes to development of muscle fatigue. Sarcolemmal processes can be impaired by the trans-sarcolemmal rundown of ion gradients for K+ , Na+ , and Ca2+ during fatiguing exercise, while changes in gradients for Cl- and Cl- conductance may exert either protective or detrimental effects on fatigue. Myocellular H+ accumulation may also contribute to fatigue development by lowering glycolytic rate and has been shown to act synergistically with inorganic phosphate (Pi) to compromise cross-bridge function. In addition, sarcoplasmic reticulum Ca2+ release function is severely affected by fatiguing exercise. Skeletal muscle has a multitude of ion transport systems that counter exercise-related ionic shifts of which the Na+ /K+ -ATPase is of major importance. Metabolic perturbations occurring during exercise can exacerbate trans-sarcolemmal ionic shifts, in particular for K+ and Cl- , respectively via metabolic regulation of the ATP-sensitive K+ channel (KATP ) and the chloride channel isoform 1 (ClC-1). Ion transport systems are highly adaptable to exercise training resulting in an enhanced ability to counter ionic disturbances to delay fatigue and improve exercise performance. In this article, we discuss (i) the ionic shifts occurring during exercise, (ii) the role of ion transport systems in skeletal muscle for ionic regulation, (iii) how ionic disturbances affect sarcolemmal processes and muscle fatigue, (iv) how metabolic perturbations exacerbate ionic shifts during exercise, and (v) how pharmacological manipulation and exercise training regulate ion transport systems to influence exercise performance in humans. © 2021 American Physiological Society. Compr Physiol 11:1895-1959, 2021.
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Affiliation(s)
- Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Simeon Peter Cairns
- SPRINZ, School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand.,Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Jens Bangsbo
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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Watanabe K, Holobar A. Quercetin ingestion modifies human motor unit firing patterns and muscle contractile properties. Exp Brain Res 2021; 239:1567-1579. [PMID: 33742251 PMCID: PMC8144122 DOI: 10.1007/s00221-021-06085-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/10/2021] [Indexed: 11/30/2022]
Abstract
Quercetin is a polyphenolic flavonoid that has reported to block the binding of adenosine to A1 receptors at central nervous system and increase calcium release from the sarcoplasmic reticulum at skeletal muscle. The aim of the present study was to investigate the acute effect of quercetin ingestion on motor unit activation and muscle contractile properties. High-density surface electromyography during submaximal contractions and electrically elicited contraction torque in knee extensor muscles were measured before (PRE) and 60 min after (POST) quercetin glycosides or placebo ingestions in 13 young males. Individual motor units of the vastus lateralis muscle were identified from high-density surface electromyography by the Convolution Kernel Compensation technique. Firing rates of motor units recruited at 30–50% of the maximal voluntary contraction torque (MVC) were increased from PRE to POST only with quercetin (9.0 ± 2.3 to 10.5 ± 2.0 pps, p = 0.034). Twitch torque during doublet stimulation was decreased from PRE to POST with placebo (77.1 ± 17.1 to 73.9 ± 17.6 Nm, p = 0.005), but not with quercetin (p > 0.05). For motor units recruited at < 10% of MVC, normalized firing rate were decreased with quercetin (1.52 ± 0.33 to 1.58 ± 0.35%MVC/pps, p = 0.002) but increased with placebo (1.61 ± 0.32 to 1.57 ± 0.31%MVC/pps, p = 0.005). These results suggest that ingested quercetin has the functional roles to: mitigate reduction in the muscle contractile properties, enhance activations of relatively higher recruitment threshold motor units, and inhibit activation of relatively lower recruitment threshold motor units.
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Affiliation(s)
- Kohei Watanabe
- Laboratory of Neuromuscular Biomechanics, Faculty of Liberal Studies and Sciences and School of International Liberal Studies, Chukyo University, Showa-ku, YagotohonmachiNagoya, 466-8666, Japan.
| | - Aleš Holobar
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
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11
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Caffeine effects on systemic metabolism, oxidative-inflammatory pathways, and exercise performance. Nutr Res 2020; 80:1-17. [DOI: 10.1016/j.nutres.2020.05.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 04/11/2020] [Accepted: 05/09/2020] [Indexed: 01/06/2023]
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12
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Green MS, Martin TD, Corona BT. Effect of Caffeine Supplementation on Quadriceps Performance After Eccentric Exercise. J Strength Cond Res 2019; 32:2863-2871. [PMID: 29481452 DOI: 10.1519/jsc.0000000000002530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Green, MS, Martin, TD, and Corona, BT. Effect of caffeine supplementation on quadriceps performance after eccentric exercise. J Strength Cond Res 32(10): 2863-2871, 2018-Caffeine use is common among athletes seeking to capitalize on its potential ergogenic effects. Limited research has examined caffeine's effects when used after activities that resulted in exercise-induced muscle damage (EIMD). This study examined the effect of caffeine supplementation on uninjured and injured muscle. Eight men and women (N = 16) who were physically active individuals participated in this study (age: 24.3 ± 4.3 years; height: 173.0 ± 7.0 cm, mass: 75.2 ± 11.5 kg; body fat: 18.2 ± 15.9%). One leg was assessed under uninjured and injured (100 eccentric quadriceps contractions) conditions after caffeine supplementation (6 mg·kg), with the other leg assessed under both conditions after placebo supplementation. Compared with the placebo, caffeine increased peak isokinetic torque by 6.8 ± 2.3 and 9.4 ± 2.5% in uninjured and injured muscle, respectively, but had no effect on maximal voluntary isometric torque or fatigue index in uninjured or injured muscle, with treatments exhibiting similar (p > 0.05) alterations in isometric torque (-11.9 ± 2.2%), fatigue index (-13.9 ± 3.4%), and soreness (+44.0 ± 4.7) after eccentric contractions. The results of this study suggest that caffeine possesses a similar ergogenic effect on isokinetic torque in both uninjured and injured states, but no effect on the production of isometric torque, perception of soreness, or degree of relative fatigue. Athletes should consider the potential caffeine supplementation possesses during recovery from activities that resulted in EIMD.
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Affiliation(s)
- Michael S Green
- Department of Kinesiology and Health Promotion, Troy University, Troy, Alabama
| | - Tyler D Martin
- Department of Kinesiology and Health Promotion, Troy University, Troy, Alabama
| | - Benjamin T Corona
- Department of Extremity Trauma and Regenerative Medicine, United States Army Institute of Surgical Research, San Antonio, Texas
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Effects of caffeine ingestion on the diurnal variation of cognitive and repeated high-intensity performances. Pharmacol Biochem Behav 2019; 177:69-74. [PMID: 30611752 DOI: 10.1016/j.pbb.2019.01.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 12/21/2018] [Accepted: 01/02/2019] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to evaluate the effects of caffeine ingestion on the daily variation of cognitive (i.e., reaction time (RT), attention) and repeated high-intensity exercise performances. Fifteen active males (age: 20 ± 1 years, height: 174.3 ± 4.3 cm, body-mass: 70.8 ± 3.5 kg) performed cognitive and physical tasks under two different circumstances [after a placebo or caffeine ingestion (6 mg/kg of body-mass)] at six different time-of-day (07 h00, 09 h00, 11 h00, 13 h00, 15 h00 and 17 h00) in a randomized double-blind balanced crossover design. During each session, RT, attention and 5-m multiple shuttles run test' performances were recorded. During both the placebo and the caffeine conditions, a significant diurnal variation was found with improvement of cognitive performances recorded at 11 h00 (e.g., RT: 0.37 ± 0.02-s and 0.36 ± 0.02-s for placebo and caffeine respectively) and 17 h00 (e.g., RT: 0.37 ± 0.02-s and 0.35 ± 0.03-s for placebo and caffeine respectively) compared to (i.e., worst performances) 07 h00 (e.g., RT: 0.41 ± 0.02-s and 0.38 ± 0.02-s for placebo and caffeine respectively) and 13 h00 (e.g., RT: 0.41 ± 0.02-s and 0.38 ± 0.02-s for placebo and caffeine respectively) (p < 0.05). For physical performance, improved values were recorded at 17 h00 (e.g., total distance: 730.00 ± 43.92-m and 733.93 ± 43.08-m for placebo and caffeine respectively) compared to 07 h00 (e.g., total distance: 698.14 ± 45.39-m and 709.21 ± 43.78-m for placebo and caffeine respectively) (p < 0.05). Compared to placebo, cognitive (e.g., RT: by 6.4% at 07 h00, 4.1% at 09 h00, 3.4% at 11 h00, 6.0% at 13 h00, 3.8% at 15 h00 and 3.8% at 17 h00) and physical (e.g., total distance: 1.6% at 07 h00, 0.9% at 09 h00, 0.1% at 11 h00 (p > 0.05), 0.5% at 13 h00, 1.0% at 15 h00 and 0.5% at 17 h00) performances increased at all time-of-day (p < 0.05). In conclusion, cognitive and physical performances are time-of-day dependent and caffeine is an effective ergogenic aid to improves both cognitive and physical performances especially at the moment of their lowest values.
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A Drug Repurposing Method Based on Drug-Drug Interaction Networks and Using Energy Model Layouts. Methods Mol Biol 2019; 1903:185-201. [PMID: 30547443 DOI: 10.1007/978-1-4939-8955-3_11] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Complex network representations of reported drug-drug interactions foster computational strategies that can infer pharmacological functions which, in turn, create incentives for drug repositioning. Here, we use Gephi (a platform for complex network visualization and analysis) to represent a drug-drug interaction network with drug interaction information from DrugBank 4.1. Both modularity class- and force-directed layout ForceAtlas2 are employed to generate drug clusters which correspond to nine specific drug properties. Most drugs comply with their cluster's dominant property; however, some of them seem not to be in a proper position (i.e., in accordance with their already known functions). Such cases, along with cases of drugs that are topologically placed in the overlapping or bordering zones between clusters, may indicate previously unaccounted pharmacologic functions, thus leading to potential repositionings. Out of the 1141 drugs with relevant information on their interactions in DrugBank 4.1, we confirm the predicted properties for 85% of the drugs. The high prediction rate of our methodology suggests that, at least for some of the 15% drugs that seem to be inconsistent with the predicted property, we can get very good repositioning hints. As such, we present illustrative examples of recovered well-known repositionings, as well as recently confirmed pharmacological properties.
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Neyroud D, Cheng AJ, Donnelly C, Bourdillon N, Gassner AL, Geiser L, Rudaz S, Kayser B, Westerblad H, Place N. Toxic doses of caffeine are needed to increase skeletal muscle contractility. Am J Physiol Cell Physiol 2018; 316:C246-C251. [PMID: 30566390 DOI: 10.1152/ajpcell.00269.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Discrepant results have been reported regarding an intramuscular mechanism underlying the ergogenic effect of caffeine on neuromuscular function in humans. Here, we reevaluated the effect of caffeine on muscular force production in humans and combined this with measurements of the caffeine dose-response relationship on force and cytosolic free [Ca2+] ([Ca2+]i) in isolated mouse muscle fibers. Twenty-one healthy and physically active men (29 ± 9 yr, 178 ± 6 cm, 73 ± 10 kg, mean ± SD) took part in the present study. Nine participants were involved in two experimental sessions during which supramaximal single and paired electrical stimulations (at 10 and 100 Hz) were applied to the femoral nerve to record evoked forces. Evoked forces were recorded before and 1 h after ingestion of 1) 6 mg caffeine/kg body mass or 2) placebo. Caffeine plasma concentration was measured in 12 participants. In addition, submaximal tetanic force and [Ca2+]i were measured in single mouse flexor digitorum brevis (FDB) muscle fibers exposed to 100 nM up to 5 mM caffeine. Six milligrams of caffeine per kilogram body mass (plasma concentration ~40 µM) did not increase electrically evoked forces in humans. In superfused FDB single fibers, millimolar caffeine concentrations (i.e., 15- to 35-fold above usual concentrations observed in humans) were required to increase tetanic force and [Ca2+]i. Our results suggest that toxic doses of caffeine are required to increase muscle contractility, questioning the purported intramuscular ergogenic effect of caffeine in humans.
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Affiliation(s)
- Daria Neyroud
- Institute of Sport Sciences, University of Lausanne , Lausanne , Switzerland
| | - Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet , Stockholm , Sweden
| | - Chris Donnelly
- Institute of Sport Sciences, University of Lausanne , Lausanne , Switzerland
| | - Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne , Lausanne , Switzerland
| | - Anne-Laure Gassner
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Lausanne, Switzerland
| | - Laurent Geiser
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Lausanne, Switzerland
| | - Serge Rudaz
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Lausanne, Switzerland
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne , Lausanne , Switzerland
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet , Stockholm , Sweden
| | - Nicolas Place
- Institute of Sport Sciences, University of Lausanne , Lausanne , Switzerland
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Souissi M, Chikh N, Affès H, Sahnoun Z. Caffeine reversal of sleep deprivation effects on alertness, mood and repeated sprint performances in physical education students. BIOL RHYTHM RES 2018. [DOI: 10.1080/09291016.2017.1413765] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Makram Souissi
- Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia
| | - Najiba Chikh
- Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia
| | - Hanène Affès
- Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia
| | - Zouheir Sahnoun
- Laboratory of Pharmacology, Faculty of Medicine, University of Sfax, Tunisia
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Caffeine increases the velocity of rapid eye movements in unfatigued humans. Psychopharmacology (Berl) 2017; 234:2311-2323. [PMID: 28536868 DOI: 10.1007/s00213-017-4638-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 05/02/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Caffeine is a widely used dietary stimulant that can reverse the effects of fatigue on cognitive, motor and oculomotor function. However, few studies have examined the effect of caffeine on the oculomotor system when homeostasis has not been disrupted by physical fatigue. This study examined the influence of a moderate dose of caffeine on oculomotor control and visual perception in participants who were not fatigued. METHODS Within a placebo-controlled crossover design, 13 healthy adults ingested caffeine (5 mg·kg-1 body mass) and were tested over 3 h. Eye movements, including saccades, smooth pursuit and optokinetic nystagmus, were measured using infrared oculography. RESULTS Caffeine was associated with higher peak saccade velocities (472 ± 60° s-1) compared to placebo (455 ± 62° s-1). Quick phases of optokinetic nystagmus were also significantly faster with caffeine, whereas pursuit eye movements were unchanged. Non-oculomotor perceptual tasks (global motion and global orientation processing) were unaffected by caffeine. CONCLUSIONS These results show that oculomotor control is modulated by a moderate dose of caffeine in unfatigued humans. These effects are detectable in the kinematics of rapid eye movements, whereas pursuit eye movements and visual perception are unaffected. Oculomotor functions may be sensitive to changes in central catecholamines mediated via caffeine's action as an adenosine antagonist, even when participants are not fatigued.
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McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine’s effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev 2016; 71:294-312. [DOI: 10.1016/j.neubiorev.2016.09.001] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 08/26/2016] [Accepted: 09/04/2016] [Indexed: 12/31/2022]
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Smirmaul BPC, de Moraes AC, Angius L, Marcora SM. Effects of caffeine on neuromuscular fatigue and performance during high-intensity cycling exercise in moderate hypoxia. Eur J Appl Physiol 2016; 117:27-38. [PMID: 27864638 PMCID: PMC5306327 DOI: 10.1007/s00421-016-3496-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 10/24/2016] [Indexed: 11/24/2022]
Abstract
Purpose To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. Methods Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg−1) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design. Results Caffeine significantly improved time to exhaustion by 12%. A significant decrease in subjective fatigue was found after caffeine consumption. Perception of effort and surface electromyographic signal amplitude of the vastus lateralis were lower and heart rate was higher in the caffeine condition when compared to placebo. However, caffeine did not reduce the peripheral and central fatigue induced by high-intensity cycling exercise in moderate hypoxia. Conclusion The caffeine-induced improvement in time to exhaustion during high-intensity cycling exercise in moderate hypoxia seems to be mediated by a reduction in perception of effort, which occurs despite no reduction in neuromuscular fatigue.
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Affiliation(s)
- Bruno P C Smirmaul
- Department of Physical Education, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | | | - Luca Angius
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent at Medway, Chatham Maritime, Kent, ME4 4AG, UK
| | - Samuele M Marcora
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent at Medway, Chatham Maritime, Kent, ME4 4AG, UK.
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Connell CJW, Thompson B, Kuhn G, Claffey MP, Duncan S, Gant N. Fatigue related impairments in oculomotor control are prevented by caffeine. Sci Rep 2016; 6:26614. [PMID: 27222342 PMCID: PMC4879569 DOI: 10.1038/srep26614] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 05/04/2016] [Indexed: 01/26/2023] Open
Abstract
Strenuous exercise can result in an inability of the central nervous system to drive skeletal muscle effectively, a phenomenon known as central fatigue. The impact of central fatigue on the oculomotor system is currently unexplored. Fatigue that originates in the central nervous system may be related to perturbations in the synthesis and metabolism of several neurotransmitters. In this study we examine central fatigue in the oculomotor system after prolonged exercise. The involvement of central neurotransmission was explored by administering caffeine during exercise. Within a double-blind, randomized, repeated measures, crossover design, 11 cyclists consumed a placebo or caffeine solution during 180 min of stationary cycling. Saccadic eye movements were measured using infra-red oculography. Exercise decreased saccade velocity by 8% (placebo trial). This effect was reversed by caffeine, whereby velocity was increased by 11% after exercise. A non-oculomotor perceptual task (global motion processing) was unaffected by exercise. The human oculomotor system is impaired by strenuous exercise of the locomotor system. Caffeine exerts a protective effect on oculomotor control, which could be related to up-regulated central neurotransmission. In addition, cortical processes supporting global motion perception appear to be robust to fatigue.
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Affiliation(s)
- Charlotte J W Connell
- Department of Exercise Sciences, Centre for Brain Research, University of Auckland, Auckland, NZ
| | - Benjamin Thompson
- School of Optometry and Vision Science, University of Waterloo, Canada
| | - Gustav Kuhn
- Department of Psychology, Goldsmiths, University of London, London, UK
| | | | - Shelley Duncan
- Department of Exercise Sciences, Centre for Brain Research, University of Auckland, Auckland, NZ
| | - Nicholas Gant
- Department of Exercise Sciences, Centre for Brain Research, University of Auckland, Auckland, NZ
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Souissi M, Abedelmalek S, Bou Dhiba D, Theodoros Nikolaidis P, Ben Awicha H, Chtourou H, Sahnoun Z. Morning caffeine ingestion increases cognitive function and short-term maximal performance in footballer players after partial sleep deprivation. BIOL RHYTHM RES 2015. [DOI: 10.1080/09291016.2015.1034975] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Souissi M, Aloui A, Chtourou H, Aouicha HB, Atheymen R, Sahnoun Z. Caffeine ingestion does not affect afternoon muscle power and fatigue during the Wingate test in elite judo players. BIOL RHYTHM RES 2015. [DOI: 10.1080/09291016.2014.994857] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Souissi M, Chtourou H, Abedelmalek S, Ghozlane IB, Sahnoun Z. The effects of caffeine ingestion on the reaction time and short-term maximal performance after 36h of sleep deprivation. Physiol Behav 2014; 131:1-6. [DOI: 10.1016/j.physbeh.2014.04.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/02/2014] [Accepted: 04/04/2014] [Indexed: 11/30/2022]
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Souissi M, Abedelmalek S, Chtourou H, Boussita A, Hakim A, Sahnoun Z. Effects of time-of-day and caffeine ingestion on mood states, simple reaction time, and short-term maximal performance in elite judoists. BIOL RHYTHM RES 2013. [DOI: 10.1080/09291016.2013.780700] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
Skeletal muscle fatigue is defined as the fall of force or power in response to contractile activity. Both the mechanisms of fatigue and the modes used to elicit it vary tremendously. Conceptual and technological advances allow the examination of fatigue from the level of the single molecule to the intact organism. Evaluation of muscle fatigue in a wide range of disease states builds on our understanding of basic function by revealing the sources of dysfunction in response to disease.
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Affiliation(s)
- Jane A Kent-Braun
- Department of Kinesiology, University of Massachusetts-Amherst, Amherst, Massachusetts, USA.
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PALLARÉS JESÚSG, FERNÁNDEZ-ELÍAS VALENTÍNE, ORTEGA JUANF, MUÑOZ GLORIA, MUÑOZ-GUERRA JESÚS, MORA-RODRÍGUEZ RICARDO. Neuromuscular Responses to Incremental Caffeine Doses. Med Sci Sports Exerc 2013; 45:2184-92. [DOI: 10.1249/mss.0b013e31829a6672] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bottoms L, Greenhalgh A, Gregory K. The effect of caffeine ingestion on skill maintenance and fatigue in epee fencers. J Sports Sci 2013; 31:1091-9. [DOI: 10.1080/02640414.2013.764466] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Souissi M, Abedelmalek S, Chtourou H, Atheymen R, Hakim A, Sahnoun Z. Effects of morning caffeine' ingestion on mood States, simple reaction time, and short-term maximal performance on elite judoists. Asian J Sports Med 2012; 3:161-8. [PMID: 23012635 PMCID: PMC3445643 DOI: 10.5812/asjsm.34607] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 02/15/2012] [Indexed: 11/16/2022] Open
Abstract
PURPOSE The purpose of the present study was to evaluate the ergogenic effect of caffeine ingestion on mood state, simple reaction time, and muscle power during the Wingate test recorded in the morning on elite Judoists. METHODS TWELVE ELITE JUDOISTS (AGE: 21.08 ± 1.16 years, body mass: 83.75 ± 20.2 kg, height: 1.76 ±6.57 m) participated in this study. Mood states, simple reaction time, and muscle power during the Wingate test were measured during two test sessions at 07:00 h and after placebo or caffeine ingestion (i.e. 5 mg/kg). Plasma concentrations of caffeine were measured before (T0) and 1-h after caffeine' ingestion (T1) and after the Wingate test (T3). RESULTS Our results revealed an increase of the anxiety and the vigor (P<0.01), a reduction of the simple reaction time (P<0.001) and an improvement of the peak and mean powers during the Wingate test. However, the fatigue index during this test was unaffected by the caffeine ingestion. In addition, plasma concentration of caffeine was significantly higher at T1 in comparison with T0. CONCLUSIONS In conclusion, the results of this study suggest that morning caffeine ingestion has ergogenic properties with the potential to benefit performance, increase anxiety and vigor, and decrease the simple reaction time.
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Affiliation(s)
- Makram Souissi
- Laboratory of Pharmacology, Faculty of medicine, University of Sfax, Tunisia
- Research Unit, High Institute of Sport and Physical Education, University of Sfax, Tunisia
| | - Salma Abedelmalek
- Research Unit, High Institute of Sport and Physical Education, University of Sfax, Tunisia
- Department of Physiology, Faculty of Medicine, University of Sousse, Tunisia
| | - Hamdi Chtourou
- Research Unit, High Institute of Sport and Physical Education, University of Sfax, Tunisia
- Research Laboratory “Sports performance optimization” National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
- Corresponding Author:Address: National Center of Medicine and Science in Sports, Bp263, Ave Med Ali Akid, 1004 El Menzah, Tunis, Tunisia. E-mail:
| | - Rim Atheymen
- Laboratory of Pharmacology, Faculty of medicine, University of Sfax, Tunisia
| | - Ahmed Hakim
- Laboratory of Pharmacology, Faculty of medicine, University of Sfax, Tunisia
| | - Zouhair Sahnoun
- Laboratory of Pharmacology, Faculty of medicine, University of Sfax, Tunisia
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Acker-Hewitt TL, Shafer BM, Saunders MJ, Goh Q, Luden ND. Independent and combined effects of carbohydrate and caffeine ingestion on aerobic cycling performance in the fed state. Appl Physiol Nutr Metab 2012; 37:276-83. [PMID: 22436075 DOI: 10.1139/h11-160] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to examine the independent and combined effects of carbohydrate and caffeine ingestion on performance and various physiological parameters during aerobic cycling (∼1 h). Ten male cyclists (28 ± 9 years, 73 ± 6 kg, 66 ± 9 mL·kg(-1)·min(-1) maximal oxygen consumption) performed 20 min of steady-state (SS) cycling (60% peak power (W(max))) followed by a simulated 20-km time trial (TT) under placebo (PLA), carbohydrate (CHO), caffeine (CAF), and combined CAF-CHO conditions, all of which were performed in the fed state. CAF-CHO improved TT performance by 3.4% ± 2% (84 ± 57 s) compared with PLA (p < 0.05), whereas no differences were detected among CHO, CAF, and PLA. The SS respiratory exchange ratio was elevated in CHO (0.92 ± 0.03), CAF (0.96 ± 0.07), and CAF-CHO (0.95 ± 0.02) compared with PLA (0.89 ± 0.03) (p < 0.05). Post-SS and post-TT blood glucose levels were also elevated in CAF-CHO (88.3 ± 16.7 mg·dL(-1) and 111.2 ± 33.5 mg·dL(-1), respectively) compared with PLA (74.5 ± 9.8 mg·dL(-1) and 85.4 ± 17.6 mg·dL(-1), respectively) (p < 0.05). Treatment conditions did not differentially impact SS pulmonary ventilation, oxygen consumption, heart rate, peak quadriceps muscle strength, rating of perceived exertion, or blood lactate. CAF and CHO improved TT performance when taken together but not independently. Although the present work did not yield any definitive physiological mechanisms for the performance findings, these data suggest that cyclists in the fed state should ingest carbohydrate and caffeine together to improve time trial performance.
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Effect of Caffeine on Fatigue During Submaximal Isometric Contractions at Different Knee Angles. ACTA ACUST UNITED AC 2011. [DOI: 10.2478/v10036-011-0027-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bazzucchi I, Felici F, Montini M, Figura F, Sacchetti M. Caffeine improves neuromuscular function during maximal dynamic exercise. Muscle Nerve 2011; 43:839-44. [DOI: 10.1002/mus.21995] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2010] [Indexed: 11/09/2022]
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Effect of ambient temperature on caffeine ergogenicity during endurance exercise. Eur J Appl Physiol 2010; 111:1135-46. [DOI: 10.1007/s00421-010-1734-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
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Kolnes AJ, Ingvaldsen A, Bolling A, Stuenaes JT, Kreft M, Zorec R, Shepherd PR, Jensen J. Caffeine and theophylline block insulin-stimulated glucose uptake and PKB phosphorylation in rat skeletal muscles. Acta Physiol (Oxf) 2010; 200:65-74. [PMID: 20180783 DOI: 10.1111/j.1748-1716.2010.02103.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM Caffeine and theophylline inhibit phosphatidylinositol 3-kinase (PI3-kinase) activity and insulin-stimulated protein kinase B (PKB) phosphorylation. Insulin-stimulated glucose uptake involves PI3-kinase/PKB, and the aim of the present study was to test the hypothesis that caffeine and theophylline inhibit insulin-stimulated glucose uptake in skeletal muscles. METHODS Rat epitrochlearis muscles and soleus strips were incubated with insulin and different concentrations of caffeine and theophylline for measurement of glucose uptake, force development and PKB phosphorylation. The effect of caffeine was also investigated in muscles stimulated electrically. RESULTS Caffeine and theophylline completely blocked insulin-stimulated glucose uptake in both soleus and epitrochlearis muscles at 10 mm. Furthermore, insulin-stimulated PKB Ser(473) and Thr(308) and GSK-3beta Ser(9) phosphorylation were blocked by caffeine and theophylline. Caffeine reduced and theophylline blocked insulin-stimulated glycogen synthase activation. Caffeine stimulates Ca(2+) release and force development increased rapidly to 10-20% of maximal tetanic contraction. Dantrolene (25 microm), a well-known inhibitor of Ca(2+)-release, prevented caffeine-induced force development, but caffeine inhibited insulin-stimulated glucose uptake in the presence of dantrolene. Contraction, like insulin, stimulates glucose uptake via translocation of glucose transporter-4 (GLUT4). Caffeine and theophylline reduced contraction-stimulated glucose uptake by about 50%, whereas contraction-stimulated glycogen breakdown was normal. CONCLUSION Caffeine and theophylline block insulin-stimulated glucose uptake independently of Ca(2+) release, and the likely mechanism is via blockade of insulin-stimulated PI3-kinase/PKB activation. Caffeine and theophylline also reduced contraction-stimulated glucose uptake, which occurs independently of PI3-kinase/PKB, and we hypothesize that caffeine and theophylline also inhibit glucose uptake in skeletal muscles via an additional and hitherto unknown molecule involved in GLUT4 translocation.
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Affiliation(s)
- A J Kolnes
- Department of Physiology, National Institute of Occupational Health, Oslo, Norway
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WARREN GORDONL, PARK NICOLED, MARESCA ROBERTD, MCKIBANS KIMBERLYI, MILLARD-STAFFORD MELINDAL. Effect of Caffeine Ingestion on Muscular Strength and Endurance. Med Sci Sports Exerc 2010; 42:1375-87. [DOI: 10.1249/mss.0b013e3181cabbd8] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Goldstein E, Jacobs PL, Whitehurst M, Penhollow T, Antonio J. Caffeine enhances upper body strength in resistance-trained women. J Int Soc Sports Nutr 2010; 7:18. [PMID: 20470411 PMCID: PMC2876999 DOI: 10.1186/1550-2783-7-18] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 05/14/2010] [Indexed: 11/18/2022] Open
Abstract
Background Research has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women. Methods In a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty min following supplementation, participants performed a one-repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate (HR) and blood pressure (BP) were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure. Results Repeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p ≤ 0.05) (52.9 ± 11.1 kg vs. 52.1 ± 11.7 kg) with no significant differences between conditions in 60% 1RM repetitions (p = 0.81). Systolic blood pressure was significantly greater post-exercise, with caffeine (p < 0.05) (116.8 ± 5.3 mmHg vs. 112.9 ± 4.9 mmHg). Conclusions These findings indicate a moderate dose of caffeine may be sufficient for enhancing strength performance in resistance-trained women.
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Affiliation(s)
- Erica Goldstein
- Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL 33431, USA.
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Effect of gender, age, fatigue and contraction level on electromechanical delay. Clin Neurophysiol 2010; 121:1700-6. [PMID: 20430696 DOI: 10.1016/j.clinph.2009.10.039] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 10/28/2009] [Accepted: 10/31/2009] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The aim of this study was to determine electromechanical delay (EMD) using supramaximal stimuli and to investigate its variation with gender, age, contraction level and fatigue. METHODS Fifteen male and 15 female healthy subjects (aged between 18 and 60) participated in our study. Electromyogram (EMG) recordings were taken from triceps surae muscle. While subjects contracted their muscles voluntarily at specified percentages of maximum voluntary contraction, 10 supramaximal stimuli were applied to the tibial nerve. The time lag between the onset of the EMG response (M-wave) and the onset of force generation was calculated as EMD. RESULTS EMD was found to be 8.5+/-1.3 ms (at rest condition), which is much shorter than those reported in previous studies. Although EMD did not significantly vary with gender (P>0.05), it decreased significantly with escalating muscle contraction level (P<0.05) and increased significantly with advancing age and with fatigue (P<0.05). CONCLUSIONS EMD was found to be considerably shorter than those reported in previous studies, and hence we discuss the possible reasons underlying this difference. We suggest that supramaximal nerve stimulation and high resolution EMG and force recording may have generated this difference. SIGNIFICANCE Current findings suggest that EMD is very sensitive to the method used to determine it. We discuss the reasons for the short EMD value that we have found in the present study.
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Goldstein ER, Ziegenfuss T, Kalman D, Kreider R, Campbell B, Wilborn C, Taylor L, Willoughby D, Stout J, Graves BS, Wildman R, Ivy JL, Spano M, Smith AE, Antonio J. International society of sports nutrition position stand: caffeine and performance. J Int Soc Sports Nutr 2010; 7:5. [PMID: 20205813 PMCID: PMC2824625 DOI: 10.1186/1550-2783-7-5] [Citation(s) in RCA: 286] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 01/27/2010] [Indexed: 11/10/2022] Open
Abstract
Position Statement: The position of The Society regarding caffeine supplementation and sport performance is summarized by the following seven points: 1.) Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (~3-6 mg/kg) and overall does not result in further enhancement in performance when consumed in higher dosages (≥ 9 mg/kg). 2.) Caffeine exerts a greater ergogenic effect when consumed in an anhydrous state as compared to coffee. 3.) It has been shown that caffeine can enhance vigilance during bouts of extended exhaustive exercise, as well as periods of sustained sleep deprivation. 4.) Caffeine is ergogenic for sustained maximal endurance exercise, and has been shown to be highly effective for time-trial performance. 5.) Caffeine supplementation is beneficial for high-intensity exercise, including team sports such as soccer and rugby, both of which are categorized by intermittent activity within a period of prolonged duration. 6.) The literature is equivocal when considering the effects of caffeine supplementation on strength-power performance, and additional research in this area is warranted. 7.) The scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance that would negatively affect performance.
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Tarnopolsky MA. Caffeine and Creatine Use in Sport. ANNALS OF NUTRITION AND METABOLISM 2010; 57 Suppl 2:1-8. [DOI: 10.1159/000322696] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Candow DG, Kleisinger AK, Grenier S, Dorsch KD. Effect of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults. J Strength Cond Res 2009; 23:1271-5. [PMID: 19528841 DOI: 10.1519/jsc.0b013e3181a026c2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Consuming sugar-free Red Bull energy drink before exercise has become increasingly popular among exercising individuals. The main purported active ingredient in sugar-free Red Bull is caffeine, which has been shown to increase aerobic exercise performance. The purpose of this study was to determine the effects of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults. Physically active university students (n = 17, 9 men, 8 woman; 21 +/- 4 years, 73.4 +/- 3.1 kg, 175.1 +/- 3.2 cm) participated in a double-blind, crossover, repeated-measures study where they were randomized to supplement with sugar-free Red Bull (2 mg x kg(-1) body mass caffeine or approximately 147 mg caffeine; 4 kcal/250 mL) and noncaffeinated, sugar-free placebo (lemon-lime flavored soft drink, tonic water, lime juice; 4 kcal/250 mL) separated by 7 days. Exercise capacity was assessed by a run time-to-exhaustion test at 80% Vo2max, perceived exertion was assessed immediately after exercise, and blood lactate was measured before and after exercise. There were no differences in run time-to-exhaustion (Red Bull: 12.6 +/- 3.8 minutes, placebo: 11.8 +/- 3.4 minutes), perceived exertion (Red Bull: 17.1 +/- 2.0, placebo: 16.6 +/- 1.8), or blood lactate between groups. In conclusion, sugar-free Red Bull energy drink did not influence high-intensity run time-to-exhaustion in young adults.
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Affiliation(s)
- Darren G Candow
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada.
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Affiliation(s)
- J K Davis
- Department of Health and Human Performance, Texas A&M University-Commerce, Commerce, Texas, USA.
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Tarnopolsky MA. Effect of caffeine on the neuromuscular system--potential as an ergogenic aid. Appl Physiol Nutr Metab 2009; 33:1284-9. [PMID: 19088790 DOI: 10.1139/h08-121] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ergogenic effect of caffeine on endurance exercise performance is multifactorial; however, there is evidence for an effect on both the central nervous system and the excitation-contraction coupling of skeletal muscle. The increase in exercise performance seen following intracerebroventrical caffeine injection in rats provides strong evidence for a central ergogenic effect. The central ergogenic effect is not likely related to the ability of caffeine to promote wakefulness, but could be due to an increase in the pain and effort perception threshold. There is no evidence that caffeine alters peripheral nerve conduction velocity or neuromuscular transmission, and 1 study showed that motor unit synchronization was not altered by caffeine. Studies have also shown that caffeine can have a direct effect on skeletal muscle that could be ergogenic. For example, patients with high cervical spinal cord lesions showed improvements in stimulated contractile force during cycling, in spite of the fact that they have no peripheral pain input and no sympathetic nervous system response. Two studies have found a potentiation of force production during submaximal stimulation intensities, and 1 found that the M-wave amplitude was not altered by caffeine. Together, these studies suggest that caffeine can enhance contractile force during submaximal contractions by potentiating calcium release from the ryanodine receptor, not by altering sarcoplasmic excitability. Furthermore, the potentiation of force during submaximal electrical stimulation is identical in habitual and nonhabitual caffeine consumers. In summary, the ergogenic effects of caffeine during endurance activity are mediated partly by enhanced contractile force and partly by a reduction in perceived exertion, possibly though a blunting of effort and (or) pain.
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Affiliation(s)
- Mark A Tarnopolsky
- Departments of Pediatrics and Medicine, McMaster University, Hamilton, ON L8N3Z5, Canada.
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Abstract
PURPOSE OF REVIEW To present food components showing evidence for improved sport performance in the light of the scientific literature from the past 2 years. RECENT FINDINGS Appropriate nutrition is essential for sport performance. Nutritional products containing carbohydrates, proteins, vitamins, and minerals have been widely used by athletes to provide something extra to the daily allowance. Currently, the field of interest is shifting from macronutrients and fluids to physiologically active isolated food components. Several of them have been demonstrated to improve sport performance at a higher level than expected with a well balanced diet. In the present review, we will focus on the benefits of creatine, caffeine, branched-chain amino acids, and more particularly leucine, beta-alanine, bicarbonate, and glycerol ingestion on exercise performance. SUMMARY A bulk of products are sold on the market labeled with various performance benefit statements without any scientific evidence. These food components are often used without a full understanding or evaluation of the potential benefits and risks associated with their use. There is thus a real need to classify food components on the basis of their evidence-based effectiveness.
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Affiliation(s)
- Louise Deldicque
- Université catholique de Louvain, Institut d'éducation physique et de réadaptation, Louvain-la-Neuve, Belgium
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DEL COSO JUAN, ESTEVEZ EMMA, MORA-RODRIGUEZ RICARDO. Caffeine Effects on Short-Term Performance during Prolonged Exercise in the Heat. Med Sci Sports Exerc 2008; 40:744-51. [DOI: 10.1249/mss.0b013e3181621336] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Astorino TA, Rohmann RL, Firth K. Effect of caffeine ingestion on one-repetition maximum muscular strength. Eur J Appl Physiol 2007; 102:127-32. [PMID: 17851681 DOI: 10.1007/s00421-007-0557-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2007] [Indexed: 10/22/2022]
Abstract
Multiple studies corroborate the ergogenic properties of caffeine (CAF) for endurance performance, yet fewer investigations document the efficacy of acute caffeine intake for intense, short-term exercise. The aim of the study was to determine the ergogenic potential of caffeine during testing of muscular strength and endurance. Twenty-two resistance-trained men ingested CAF (6 mg/kg) or placebo (PL) 1 h pre-exercise in a randomized, double-blind crossover design. They refrained from caffeine intake and strenuous exercise 48 and 24 h, respectively, pre-visit. Initially, resting heart rate and blood pressure were obtained followed by one-repetition maximum (1-RM) testing on the barbell bench press and leg press. Upon determination of 1-RM, participants completed repetitions to failure at 60%1-RM. Heart rate, blood pressure, and rating of perceived exertion (RPE) were measured after the final repetition. Compared to PL, there was no effect (P > 0.05) of caffeine on muscular strength, as 1-RM bench press (116.4 +/- 23.6 kg vs. 114.9 +/- 22.8 kg) and leg press (410.6 +/- 92.4 kg vs. 394.8 +/- 95.4 kg) were similar. Total weight lifted during the 60% 1-RM trial was 11 and 12% higher for the bench press and leg press with caffeine compared to placebo, yet did not reach significance. RPE was similar at the end of resistance exercise with CAF vs. PL. Acute caffeine intake does not significantly alter muscular strength or endurance during intense bench press or leg press exercise, yet the practical importance of the increased muscular endurance remains to be explored.
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Affiliation(s)
- Todd A Astorino
- Department of Kinesiology, CSU - San Marcos, 333 S. Twin Oaks Valley Road, MH 352, San Marcos, CA 92096-0001, USA.
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Greer F, Morales J, Coles M. Wingate performance and surface EMG frequency variables are not affected by caffeine ingestion. Appl Physiol Nutr Metab 2006; 31:597-603. [PMID: 17111014 DOI: 10.1139/h06-030] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ergogenic effect of caffeine and its mechanism of action on short-term, high-intensity exercise are controversial. One proposed mechanism is caffeine’s stimulatory effect on the central nervous system and thus, motor-unit excitation. The latter is non-invasively determined from surface electromyographic signal (EMG) frequency measures. The purpose of this study was to determine if power output and surface EMG frequency variables during high-intensity cycling were altered following caffeine ingestion. Eighteen recreationally active college males (mean ± SD age, 21.5 ± 1.8 y; height, 181.8 ± 0.5 cm; body mass, 84.7 ± 11.4 kg) performed the Wingate test (WG) after ingestion of gelatin capsules containing either placebo (PL; dextrose) or caffeine (CAFF; 5 mg/kg body mass). The trials were separated by 1 week and subjects were asked to withdraw from all caffeine-containing products for 48 h before each trial. From the resulting power–time records, peak power (PP; highest power output in 5 s), minimum power (MP; lowest power output in 5 s), and the percent decline in power (Pd) were calculated. Surface EMG records of the right vastus lateralis (VL) and the gastrocnemius (GA) muscles corresponding to the PP and MP periods were collected and used to determine the integrated electromyogram (IEMG), the mean (MNPF), and the median (MDPF) of the signal’s power spectrum. A 2-way repeated measures analysis of variance (ANOVA) (treatment × time) was conducted to determine the effect of caffeine on these variables across levels of time. Caffeine ingestion had no effect on PP (PL, 1049 ± 192 W; CAFF, 1098 ± 198 W), MP (PL, 762 ± 104 W; CAFF, 802 ± 124 W), or the Pd (PL, 47% ± 8.9%; CAFF, 48.2% ± 7.3%) compared with the placebo. For both muscles, MNPF and MDPF diminished significantly (p < 0.001) across time and to a similar degree in both the CAFF and PL trials. Regardless of muscle, CAFF had no effect on the percent change in IEMG from the first 5 s to the last 5 s. For both treatments, the GA displayed a significantly (p < 0.05) greater pre vs. post percent decline in the EMG signal amplitude compared with the VL. These results indicate that caffeine does not impact power output during a 30 s high-intensity cycling bout. Furthermore, these data suggest that caffeine does not impact the neuromuscular drive as indicated by the similar IEMG scores between treatments. Similarly, caffeine does not seem to impact the frequency content of the surface EMG signal and thus the nature of recruited motor units before and after the expression of fatigue. The lack of decline in the IEMG in the VL despite the decline in power output over the course of the WG suggests a peripheral as opposed to a neural mechanism of fatigue in this muscle. The significant difference in the pre vs. post percent decline in the GA IEMG score further supports this notion. The pre vs. post decline in the IEMG noted in the GA may suggest a fatigue-triggered change in pedaling mechanics that may promote dominance of knee extensors with less reliance on plantar flexors.
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Affiliation(s)
- Felicia Greer
- Department of Kinesiology, 5275 N. Campus Dr. M/S SG 28, California State University, Fresno, CA 93740, USA.
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Cerqueira V, de Mendonça A, Minez A, Dias AR, de Carvalho M. Does caffeine modify corticomotor excitability? Neurophysiol Clin 2006; 36:219-26. [PMID: 17095411 DOI: 10.1016/j.neucli.2006.08.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 06/29/2006] [Indexed: 11/30/2022] Open
Abstract
AIMS To test the influence of caffeine on the lower and upper motor neuron excitability. METHODS In Experiment A, 18 healthy subjects received 200 mg of caffeine or placebo, in a randomized, double-blind, placebo-controlled design protocol. Mean F-waves amplitude, amplitude of the motor response evoked by magnetic stimulation (MEP), MEP duration, cortical silent period (CSP), central conduction time, and cortical threshold were evaluated. In Experiment B, 6 healthy controls received 400 mg of caffeine, the peripheral silent period (PSP) and CSP were evaluated. CSP was recorded bilaterally in biceps brachii (intensity 10% above threshold) and abductor digiti minimi (ADM) (intensity at 10% and 50% above threshold). Muscle contraction was above 50% of the maximum force in both experiments. Latencies were defined by a technician who was not aware of this investigation. Serum caffeine level was evaluated. RESULTS In Experiment A, only the CSP, recorded in both ADM with intensity at 10% above threshold showed a significant change after caffeine (decrease of 17.1+/-34.0 ms, about 12% reduction). In Experiment B, PSP did not change, but CSP tested with intensities 10% above threshold was significantly decreased by 20.8+/-34.4 ms in ADM and 13.5+/-13.8 ms in biceps (about 13 and 16%, respectively). Serum caffeine level clearly increased after consumption but no correlation could be found between these levels and CSP reduction. CONCLUSIONS In our investigation, caffeine elicited a consistent decrease of the CSP, suggesting that caffeine increases cortical neuronal excitability.
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Affiliation(s)
- V Cerqueira
- Dementia Group, Institute of Molecular Medicine, Faculty of Medicine of Lisbon and Hospital de Santa Maria, Portugal
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Kalmar JM, Del Balso C, Cafarelli E. Increased spinal excitability does not offset central activation failure. Exp Brain Res 2006; 173:446-57. [PMID: 16506005 DOI: 10.1007/s00221-006-0383-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Accepted: 01/27/2006] [Indexed: 11/30/2022]
Abstract
We hypothesized that if reduced spinal excitability contributes to central activation failure, then a caffeine-induced increase in spinal excitability would enhance postfatigue maximal voluntary activation and maximal voluntary contraction (MVC). Ten male volunteer subjects attended two laboratory sessions separated by at least 1 week. Contractile and electrical properties were assessed before, and 1 h after oral administration of caffeine (6 mg/kg) or placebo (all-purpose flour), and again following a fatigue protocol. The slope of the H reflex recruitment curve, normalized to that of the M wave (H(slp)/M(slp)), was used to estimate spinal excitability. Maximal voluntary activation was assessed using maximal EMG (EMG(max)) and twitch interpolation. Postfatigue, MVC torque declined (P<0.05) to 75.2+/-12.7 and 70.2+/-9.3% of the prefatigue values in the placebo (PL) and caffeine (CF) trials, respectively, and remained depressed throughout the recovery period. This was accompanied by a decline in % activation (P<0.05) from 99.6+/-0.3% (PL) and 99.8+/-0.3% (CF) to 94.8+/-3.5% (PL) and 95.3+/-5.0% (CF), indicating the presence of central activation failure. Caffeine offset the decline in H(slp)/M(slp )observed in the placebo trial (P<0.05), but it did not prevent the decline in maximal voluntary activation or MVC torque. Furthermore, although the decline in spinal excitability was correlated to the decline in EMG(max) (r=0.55, P<0.05) it was not correlated with the decline in % activation or MVC torque. Thus a fatigue-induced decline in spinal excitability did not limit maximal activation.
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Affiliation(s)
- J M Kalmar
- Department of Biology, Rm 346 Bethune College, York University, Toronto, ON, Canada
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Stuart GR, Hopkins WG, Cook C, Cairns SP. Multiple effects of caffeine on simulated high-intensity team-sport performance. Med Sci Sports Exerc 2006; 37:1998-2005. [PMID: 16286872 DOI: 10.1249/01.mss.0000177216.21847.8a] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Caffeine enhances performance of single bouts of endurance exercise, but its effects on repeated bouts typical of those in high-intensity team sports are unclear. PURPOSE To investigate effects of caffeine in a performance test simulating physical and skill demands of a rugby union game. METHODS The study was a double-blind, randomized, crossover design in which nine competitive male rugby players ingested either caffeine (6 mg.kg(-1) body mass) or placebo (dextrose) 70 min before performing a rugby test. Each test consisted of seven circuits in each of two 40-min halves with a 10-min half-time rest. Each circuit included stations for measurement of sprint time (two straight-line and three agility sprints), power generation in two consecutive drives, and accuracy for passing balls rapidly. Interstitial fluid was sampled transdermally by electrosonophoresis before ingestion of caffeine or placebo and then before testing, at half-time, and immediately after testing; samples were assayed chromatographically for caffeine and epinephrine concentrations. RESULTS The effects of caffeine on mean performance (+/-90% confidence limits) over all 14 circuits were: sprint speeds, 0.5% (+/-1.7%) through 2.9% (+/-1.3%); first-drive power, 5.0% (+/-2.5%); second-drive power, -1.2% (+/-6.8%); and passing accuracy, 9.6% (+/-6.1%). The enhancements were mediated partly through a reduction of fatigue that developed throughout the test and partly by enhanced performance for some measures from the first circuit. Caffeine produced a 51% (+/-11%) increase in mean epinephrine concentration; correlations between individual changes in epinephrine concentration and changes in performance were mostly unclear, but there were some strong positive correlations with sprint speeds and a strong negative correlation with passing accuracy. CONCLUSION Caffeine is likely to produce substantial enhancement of several aspects of high-intensity team-sport performance.
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Affiliation(s)
- Gene R Stuart
- Division of Sport and Recreation, Auckland University of Technology, New Zealand
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Abstract
Caffeine is a very common CNS stimulant that has been of interest to physiologists because of its direct effects on skeletal muscle in vitro, as well as ergogenic effects on laboratory tests of human performance. While in vitro studies have clearly demonstrated the effects of the drug on the CNS, the effects of caffeine on the voluntary activation of muscle in humans are less defined. Voluntary as well as involuntary supraspinal input, alpha motor neuron membrane properties, and afferent feedback to spinal and supraspinal neurons all modulate voluntary muscle activation, and caffeine may therefore alter muscle activation at several sites along the motor pathway. This review explores the effects of caffeine on voluntary muscle activation that have been demonstrated in recent human studies and discusses the central mechanisms that may enhance activation. Evidence of caffeine's effects on the motor evoked potential, Hoffman reflex, self-sustained firing of the alpha motor neuron, and pain and force sensation are presented as well as limitations and considerations of using the drug in human neuromuscular studies.
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Affiliation(s)
- Jayne M Kalmar
- Department of Biology, York University, Toronto, Ontario, CANADA.
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Doherty M, Smith PM. Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis. Scand J Med Sci Sports 2005; 15:69-78. [PMID: 15773860 DOI: 10.1111/j.1600-0838.2005.00445.x] [Citation(s) in RCA: 288] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to use the meta-analytic approach to examine the effects of caffeine ingestion on ratings of perceived exertion (RPE). Twenty-one studies with 109 effect sizes (ESs) met the inclusion criteria. Coding incorporated RPE scores obtained both during constant load exercise (n=89) and upon termination of exhausting exercise (n=20). In addition, when reported, the exercise performance ES was also computed (n=16). In comparison to placebo, caffeine reduced RPE during exercise by 5.6% (95% CI (confidence interval), -4.5% to -6.7%), with an equivalent RPE ES of -0.47 (95% CI, -0.35 to -0.59). These values were significantly greater (P<0.05) than RPE obtained at the end of exercise (RPE % change, 0.01%; 95% CI, -1.9 to 2.0%; RPE ES, 0.00, 95% CI, -0.17 to 0.17). In addition, caffeine improved exercise performance by 11.2% (95% CI; 4.6-17.8%). Regression analysis revealed that RPE obtained during exercise could account for approximately 29% of the variance in the improvement in exercise performance. The results demonstrate that caffeine reduces RPE during exercise and this may partly explain the subsequent ergogenic effects of caffeine on performance.
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Affiliation(s)
- M Doherty
- Division of Sport and Exercise Science, University of Luton, Luton, Beds LU1 3JU, UK.
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