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Anders JPV, Neltner TJ, Smith RW, Keller JL, Housh TJ, Daugherty FJ, Tempesta MS, Dash AK, Munt DJ, Schmidt RJ, Johnson GO. The effects of phosphocreatine disodium salts plus blueberry extract supplementation on muscular strength, power, and endurance. J Int Soc Sports Nutr 2021; 18:60. [PMID: 34503541 PMCID: PMC8427883 DOI: 10.1186/s12970-021-00456-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 07/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Numerous studies have demonstrated the efficacy of creatine supplementation for improvements in exercise performance. Few studies, however, have examined the effects of phosphocreatine supplementation on exercise performance. Furthermore, while polyphenols have antioxidant and anti-inflammatory properties, little is known regarding the influence of polyphenol supplementation on muscular strength, power, and endurance. Thus, the purpose of the present study was to compare the effects of 28 days of supplementation with phosphocreatine disodium salts plus blueberry extract (PCDSB), creatine monohydrate (CM), and placebo on measures of muscular strength, power, and endurance. METHODS Thirty-three men were randomly assigned to consume either PCDSB, CM, or placebo for 28 days. Peak torque (PT), average power (AP), and percent decline for peak torque (PT%) and average power (AP%) were assessed from a fatigue test consisting of 50 maximal, unilateral, isokinetic leg extensions at 180°·s- 1 before and after the 28 days of supplementation. Individual responses were assessed to examine the proportion of subjects that exceeded a minimal important difference (MID). RESULTS The results demonstrated significant (p < 0.05) improvements in PT for the PCDSB and CM groups from pre- (99.90 ± 22.47 N·m and 99.95 ± 22.50 N·m, respectively) to post-supplementation (119.22 ± 29.87 N·m and 111.97 ± 24.50 N·m, respectively), but no significant (p = 0.112) change for the placebo group. The PCDSB and CM groups also exhibited significant improvements in AP from pre- (140.18 ± 32.08 W and 143.42 ± 33.84 W, respectively) to post-supplementation (170.12 ± 42.68 W and 159.78 ± 31.20 W, respectively), but no significant (p = 0.279) change for the placebo group. A significantly (p < 0.05) greater proportion of subjects in the PCDSB group exceeded the MID for PT compared to the placebo group, but there were no significant (p > 0.05) differences in the proportion of subjects exceeding the MID between the CM and placebo groups or between the CM and PCDSB groups. CONCLUSIONS These findings indicated that for the group mean responses, 28 days of supplementation with both PCDSB and CM resulted in increases in PT and AP. The PCDSB, however, may have an advantage over CM when compared to the placebo group for the proportion of individuals that respond favorably to supplementation with meaningful increases in muscular strength.
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Affiliation(s)
- John Paul V Anders
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68510, USA.
| | - Tyler J Neltner
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68510, USA
| | - Robert W Smith
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68510, USA
| | - Joshua L Keller
- Department of Health, Kinesiology and Sport, University of South Alabama, Mobile, AL, 36688, USA
| | - Terry J Housh
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68510, USA
| | | | | | - Alekha K Dash
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Omaha, NE, 68178, USA
| | - Daniel J Munt
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Omaha, NE, 68178, USA
| | - Richard J Schmidt
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68510, USA
| | - Glen O Johnson
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68510, USA
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Short term creatine loading without weight gain improves sprint, agility and leg strength performance in female futsal players. Sci Sports 2019. [DOI: 10.1016/j.scispo.2018.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yáñez-Silva A, Buzzachera CF, Piçarro IDC, Januario RSB, Ferreira LHB, McAnulty SR, Utter AC, Souza-Junior TP. Effect of low dose, short-term creatine supplementation on muscle power output in elite youth soccer players. J Int Soc Sports Nutr 2017; 14:5. [PMID: 28190980 PMCID: PMC5296953 DOI: 10.1186/s12970-017-0162-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 02/01/2017] [Indexed: 12/25/2022] Open
Abstract
Background To determine the effects of a low dose, short-term Creatine monohydrate (Cr) supplementation (0.03 g.kg.d−1 during 14 d) on muscle power output in elite youth soccer players. Methods Using a two-group matched, double blind, placebo-controlled design, nineteen male soccer players (mean age = 17.0 ± 0.5 years) were randomly assigned to either Cr (N = 9) or placebo (N = 10) group. Before and after supplementation, participants performed a 30s Wingate Anaerobic Test (WAnT) to assess peak power output (PPO), mean power output (MPO), fatigue index (FI), and total work. Results There were significant increases in both PPO and MPO after the Cr supplementation period (P ≤ 0.05) but not the placebo period. There were also significant increases in total work, but not FI, after the Cr supplementation and placebo periods (P ≤ 0.05). Notably, there were differences in total work between the Cr and placebo groups after (P ≤ 0.05) but not before the 14 d supplementation period. Conclusion There is substantial evidence to indicate that a low-dose, short-term oral Cr supplementation beneficially affected muscle power output in elite youth soccer players.
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Affiliation(s)
- Aquiles Yáñez-Silva
- Dirección de Investigación, Universidad Mayor Santiago de Chile; Universidad Santo Tomás, Talca. Chile. Carrera de Educación Física, Santiago de Chile, Chile
| | - Cosme F Buzzachera
- Department of Physical Education, North University of Parana, Londrina, Brazil
| | - Ivan Da C Piçarro
- School of Physical Education, Max Planck Faculty, Indaiatuba, Brazil
| | - Renata S B Januario
- Department of Physical Education, North University of Parana, Londrina, Brazil
| | - Luis H B Ferreira
- Department of Physical Education, Research Group on Metabolism, Nutrition and Strength Training, Curitiba, Brazil
| | - Steven R McAnulty
- Department of Health and Exercise Science, Appalachian State University, Boone, USA
| | - Alan C Utter
- Department of Health and Exercise Science, Appalachian State University, Boone, USA
| | - Tacito P Souza-Junior
- Department of Physical Education, Research Group on Metabolism, Nutrition and Strength Training, Curitiba, Brazil.,Department of Health and Exercise Science, Appalachian State University, Boone, USA
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Lanhers C, Pereira B, Naughton G, Trousselard M, Lesage FX, Dutheil F. Creatine Supplementation and Lower Limb Strength Performance: A Systematic Review and Meta-Analyses. Sports Med 2016; 45:1285-1294. [PMID: 25946994 DOI: 10.1007/s40279-015-0337-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Creatine is the most widely used supplementation to increase strength performance. However, the few meta-analyses are more than 10 years old and suffer from inclusion bias such as the absence of randomization and placebo, the diversity of the inclusion criteria (aerobic/endurance, anaerobic/strength), no evaluation on specific muscles or group of muscles, and the considerable amount of conflicting results within the last decade. OBJECTIVE The objective of this systematic review was to evaluate meta-analyzed effects of creatine supplementation on lower limb strength performance. METHODS We conducted a systematic review and meta-analyses of all randomized controlled trials comparing creatine supplementation with a placebo, with strength performance of the lower limbs measured in exercises lasting less than 3 min. The search strategy used the keywords "creatine supplementation" and "performance". Dependent variables were creatine loading, total dose, duration, the time-intervals between baseline (T0) and the end of the supplementation (T1), as well as any training during supplementation. Independent variables were age, sex, and level of physical activity at baseline. We conducted meta-analyses at T1, and on changes between T0 and T1. Each meta-analysis was stratified within lower limb muscle groups and exercise tests. RESULTS We included 60 studies (646 individuals in the creatine supplementation group and 651 controls). At T1, the effect size (ES) among stratification for squat and leg press were, respectively, 0.336 (95 % CI 0.047-0.625, p = 0.023) and 0.297 (95 % CI 0.098-0.496, p = 0.003). Overall quadriceps ES was 0.266 (95 % CI 0.150-0.381, p < 0.001). Global lower limb ES was 0.235 (95 % CI 0.125-0.346, p < 0.001). Meta-analysis on changes between T0 and T1 gave similar results. The meta-regression showed no links with characteristics of population or of supplementation, demonstrating the creatine efficacy effects, independent of all listed conditions. CONCLUSION Creatine supplementation is effective in lower limb strength performance for exercise with a duration of less than 3 min, independent of population characteristic, training protocols, and supplementary doses and duration.
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Affiliation(s)
- Charlotte Lanhers
- Preventive and Occupational Medicine, University Hospital of Clermont-Ferrand (CHU), 58 rue Montalembert, Clermont-Ferrand, France
| | - Bruno Pereira
- Clinical research and innovation direction, University Hospital of Clermont-Ferrand (CHU), Clermont-Ferrand, France
| | - Geraldine Naughton
- School of Exercise Science, Australian Catholic University, Melbourne, VIC, Australia
| | - Marion Trousselard
- Neurophysiology of stress, Armies' Biomedical Research Institute, Armies' Health Service, Bretigny sur Orge, France
| | | | - Frédéric Dutheil
- School of Exercise Science, Australian Catholic University, Melbourne, VIC, Australia. .,Preventive and Occupational Medicine, University Hospital of Clermont-Ferrand (CHU), 58 rue Montalembert, Clermont-Ferrand, France. .,Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological Conditions EA3533, Blaise Pascal University, Clermont-Ferrand, France. .,Research Centre in Human Nutrition (CRNH) Auvergne, Clermont-Ferrand, France.
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Camic CL, Housh TJ, Zuniga JM, Traylor DA, Bergstrom HC, Schmidt RJ, Johnson GO, Housh DJ. The effects of polyethylene glycosylated creatine supplementation on anaerobic performance measures and body composition. J Strength Cond Res 2014; 28:825-33. [PMID: 23897021 DOI: 10.1519/jsc.0b013e3182a361a5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to examine the effects of 28 days of polyethylene glycosylated creatine (PEG-creatine) supplementation (1.25 and 2.50 g·d) on anaerobic performance measures (vertical and broad jumps, 40-yard dash, 20-yard shuttle run, and 3-cone drill), upper- and lower-body muscular strength and endurance (bench press and leg extension), and body composition. This study used a randomized, double-blind, placebo-controlled parallel design. Seventy-seven adult men (mean age ± SD, 22.1 ± 2.5 years; body mass, 81.7 ± 10.8 kg) volunteered to participate and were randomly assigned to a placebo (n = 23), 1.25 g·d of PEG-creatine (n = 27), or 2.50 g·d of PEG-creatine (n = 27) group. The subjects performed anaerobic performance measures, muscular strength (one-repetition maximum [1RM]), and endurance (80% 1RM) tests for bench press and leg extension, and underwater weighing for the determination of body composition at day 0 (baseline), day 14, and day 28. The results indicated that there were improvements (p < 0.0167) in vertical jump, 20-yard shuttle run, 3-cone drill, muscular endurance for bench press, and body mass for at least one of the PEG-creatine groups without changes for the placebo group. Thus, the present results demonstrated that PEG-creatine supplementation at 1.25 or 2.50 g·d had an ergogenic effect on lower-body vertical power, agility, change-of-direction ability, upper-body muscular endurance, and body mass.
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Affiliation(s)
- Clayton L Camic
- 1Department of Exercise and Sport Science, Human Performance Laboratory, University of Wisconsin-La Crosse, La Crosse, Wisconsin; 2Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska; 3Department of Exercise Science, Creighton University, Omaha, Nebraska; and 4Department of Oral Biology, University of Nebraska Medical Center, Lincoln, Nebraska
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Zuniga JM, Housh TJ, Camic CL, Hendrix CR, Mielke M, Johnson GO, Housh DJ, Schmidt RJ. The Effects of Creatine Monohydrate Loading on Anaerobic Performance and One-Repetition Maximum Strength. J Strength Cond Res 2012; 26:1651-6. [DOI: 10.1519/jsc.0b013e318234eba1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Sanchez-Gonzalez MA, Wieder R, Kim JS, Vicil F, Figueroa A. Creatine supplementation attenuates hemodynamic and arterial stiffness responses following an acute bout of isokinetic exercise. Eur J Appl Physiol 2011; 111:1965-71. [DOI: 10.1007/s00421-011-1832-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 01/07/2011] [Indexed: 01/27/2023]
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Gualano B, Acquesta FM, Ugrinowitsch C, Tricoli V, Serrão JC, Lancha Junior AH. Efeitos da suplementação de creatina sobre força e hipertrofia muscular: atualizações. REV BRAS MED ESPORTE 2010. [DOI: 10.1590/s1517-86922010000300013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A suplementação de creatina vem sendo utilizada amplamente na tentativa de aumentar força e massa magra em sujeitos saudáveis e atletas. Além disso, diversos estudos têm sido conduzidos no intuito de desvendar os mecanismos responsáveis pelas eventuais adaptações a esse suplemento. Diante disso, essa revisão teve como objetivos: 1) discutir os principais estudos que investigaram os efeitos da suplementação de creatina na força e hipertrofia; e 2) reunir as evidências acerca dos possíveis mecanismos responsáveis pelo aumento de força e massa magra como consequência desse suplemento, enfatizando os mais recentes achados e as perspectivas sobre o tema. De fato, existem fortes evidências demonstrando que a suplementação de creatina é capaz de promover aumentos de força e hipertrofia. Os efeitos desse suplemento sobre a retenção hídrica, o balanço proteico, a expressão de genes/proteínas associados à hipertrofia e ativação de células satélites, podem explicar as adaptações musculoesqueléticas observadas. Diante desses achados, os potenciais efeitos terapêuticos desse suplemento emergem como um futuro e promissor campo de estudo.
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Affiliation(s)
- Bruno Gualano
- Escola de Educação Física e Esporte; Faculdade de Medicina
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Sakkas GK, Mulligan K, DaSilva M, Doyle JW, Khatami H, Schleich T, Kent-Braun JA, Schambelan M. Creatine fails to augment the benefits from resistance training in patients with HIV infection: a randomized, double-blind, placebo-controlled study. PLoS One 2009; 4:e4605. [PMID: 19242554 PMCID: PMC2646129 DOI: 10.1371/journal.pone.0004605] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 01/02/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Progressive resistance exercise training (PRT) improves physical functioning in patients with HIV infection. Creatine supplementation can augment the benefits derived from training in athletes and improve muscle function in patients with muscle wasting. The objective of this study was to determine whether creatine supplementation augments the effects of PRT on muscle strength, energetics, and body composition in HIV-infected patients. METHODOLOGY/PRINCIPAL FINDINGS This is a randomized, double blind, placebo-controlled, clinical research center-based, outpatient study in San Francisco. 40 HIV-positive men (20 creatine, 20 placebo) enrolled in a 14-week study. Subjects were randomly assigned to receive creatine monohydrate or placebo for 14 weeks. Treatment began with a loading dose of 20 g/day or an equivalent number of placebo capsules for 5 days, followed by maintenance dosing of 4.8 g/day or placebo. Beginning at week 2 and continuing to week 14, all subjects underwent thrice-weekly supervised resistance exercise while continuing on the assigned study medication (with repeated 6-week cycles of loading and maintenance). The main outcome measurements included muscle strength (one repetition maximum), energetics ((31)P magnetic resonance spectroscopy), composition and size (magnetic resonance imaging), as well as total body composition (dual-energy X-ray absorptiometry). Thirty-three subjects completed the study (17 creatine, 16 placebo). Strength increased in all 8 muscle groups studied following PRT, but this increase was not augmented by creatine supplementation (average increase 44 vs. 42%, difference 2%, 95% CI -9.5% to 13.9%) in creatine and placebo, respectively). There were no differences between groups in changes in muscle energetics. Thigh muscle cross-sectional area increased following resistance exercise, with no additive effect of creatine. Lean body mass (LBM) increased to a significantly greater extent with creatine. CONCLUSIONS / SIGNIFICANCE: Resistance exercise improved muscle size, strength and function in HIV-infected men. While creatine supplementation produced a greater increase in LBM, it did not augment the robust increase in strength derived from PRT. TRIAL REGISTRATION ClinicalTrials.gov NCT00484627.
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Affiliation(s)
- Giorgos K. Sakkas
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Division of Endocrinology, San Francisco General Hospital, San Francisco, California, United States of America
- Department of Medicine, University of Thessaly, Thessaly, Greece
| | - Kathleen Mulligan
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Division of Endocrinology, San Francisco General Hospital, San Francisco, California, United States of America
| | - Makani DaSilva
- Division of Endocrinology, San Francisco General Hospital, San Francisco, California, United States of America
| | - Julie W. Doyle
- Northern California Institute for Research and Education, San Francisco, California, United States of America
| | - Hootan Khatami
- Division of Endocrinology, San Francisco General Hospital, San Francisco, California, United States of America
| | - Thomas Schleich
- Department of Chemistry & Biochemistry, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Jane A. Kent-Braun
- Department of Exercise Science, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Morris Schambelan
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Division of Endocrinology, San Francisco General Hospital, San Francisco, California, United States of America
- * E-mail:
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Deacon SJ, Vincent EE, Greenhaff PL, Fox J, Steiner MC, Singh SJ, Morgan MD. Randomized controlled trial of dietary creatine as an adjunct therapy to physical training in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2008; 178:233-9. [PMID: 18420964 DOI: 10.1164/rccm.200710-1508oc] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Skeletal muscle strength and bulk are reduced in patients with chronic obstructive pulmonary disease (COPD) and influence quality of life, survival, and utilization of health care resources. Exercise training during pulmonary rehabilitation (PR) can reverse some of these effects. In athletes and healthy elderly individuals, dietary creatine supplementation (CrS) has been shown to augment high-intensity exercise training, thereby increasing muscle mass. OBJECTIVES This article examines the effect of CrS on functional exercise capacity and muscle performance in people with COPD. METHODS One hundred subjects with COPD (mean [SD] age, 68.2 [8.2] yr; FEV(1), 44.0 [19.6] %predicted) were randomized to a double-blind, placebo-controlled, parallel group trial of CrS during 7 weeks of PR encompassing aerobic and resistance exercises. Subjects ingested creatine (22 g/d loading for 5 d; maintenance, 3.76 g/d throughout PR) or placebo. Baseline, postloading, and postrehabilitation measurements included pulmonary function, body composition, peripheral muscle strength, and functional performance (shuttle walking tests). A volunteer subgroup (n = 44) had pre- and postloading quadriceps muscle biopsies. MEASUREMENTS AND MAIN RESULTS Eighty subjects completed the trial (38 creatine, 42 placebo). All outcome measures significantly improved after PR. There were no significant differences between groups post-PR (mean [SD] change in incremental shuttle walk distance, 84 [79] m in the creatine group vs. 83.8 [60] m in the placebo group; P = 1.0; knee extensor work, 19.2 [16] Nm [Newton meters] in the creatine group vs. 19.5 [17] Nm in the placebo group; P = 0.9). Muscle biopsies showed evidence of creatine uptake. CONCLUSIONS This adequately powered, randomized, placebo-controlled trial shows that CrS does not augment the substantial training effect of multidisciplinary PR for patients with COPD. Clinical trial registered with https://portal.nihr.ac.uk/Pages/NRRArchiveSearch.aspx (NO123138126).
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Affiliation(s)
- Sarah J Deacon
- Institute for Lung Health, Department of Respiratory Medicine, Allergy and Thoracic Surgery, University Hospitals of Leicester NHS Trust, Glenfield Hospital, Leicester LE39QP, UK.
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The effect of acute creatinine monohydrate loading on wingate test results in 18-21 years old male soccer players. ACTA PHYSIOLOGICA HUNGARICA 2005; 92:221-230. [PMID: 25996269 DOI: 10.1556/aphysiol.92.2005.3-4.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Abstract
Creatine monohydrate (Cr) is perhaps one of the most widely used supplements taken in an attempt to improve athletic performance. The aim of this review is to update, summarise and evaluate the findings associated with Cr ingestion and sport and exercise performance with the most recent research available. Because of the large volume of scientific literature dealing with Cr supplementation and the recent efforts to delineate sport-specific effects, this paper focuses on research articles that have been published since 1999.Cr is produced endogenously by the liver or ingested from exogenous sources such as meat and fish. Almost all the Cr in the body is located in skeletal muscle in either the free (Cr: approximately 40%) or phosphorylated (PCr: approximately 60%) form and represents an average Cr pool of about 120-140 g for an average 70 kg person. It is hypothesised that Cr can act though a number of possible mechanisms as a potential ergogenic aid but it appears to be most effective for activities that involve repeated short bouts of high-intensity physical activity. Additionally, investigators have studied a number of different Cr loading programmes; the most common programme involves an initial loading phase of 20 g/day for 5-7 days, followed by a maintenance phase of 3-5 g/day for differing periods of time (1 week to 6 months). When maximal force or strength (dynamic or isotonic contractions) is the outcome measure following Cr ingestion, it generally appears that Cr does significantly impact force production regardless of sport, sex or age. The evidence is much more equivocal when investigating isokinetic force production and little evidence exists to support the use of Cr for isometric muscular performance. There is little benefit from Cr ingestion for the prevention or suppression of muscle damage or soreness following muscular activity. When performance is assessed based on intensity and duration of the exercises, there is contradictory evidence relative to both continuous and intermittent endurance activities. However, activities that involve jumping, sprinting or cycling generally show improved sport performance following Cr ingestion. With these concepts in mind, the focus of this paper is to summarise the effectiveness of Cr on specific performance outcomes rather than on proposed mechanisms of action. The last brief section of this review deals with the potential adverse effects of Cr supplementation. There appears to be no strong scientific evidence to support any adverse effects but it should be noted that there have been no studies to date that address the issue of long-term Cr usage.
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Affiliation(s)
- Michael G Bemben
- Neuromuscular Research Laboratory, Department of Health and Sport Sciences, University of Oklahoma, Norman, OK 73019, USA.
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Carter JM, Bemben DA, Knehans AW, Bemben MG, Witten MS. Does Nutritional Supplementation Influence Adaptability of Muscle to Resistance Training in Men Aged 48 to 72 Years. J Geriatr Phys Ther 2005; 28:40-7. [PMID: 16236227 DOI: 10.1519/00139143-200508000-00002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND PURPOSE Isotonic strength training can result in neuromuscular improvements evidenced in other forms of muscular effort, ie, isokinetic or isometric, especially in young subjects; however, it is unclear if older muscle maintains this same adaptive ability. Additionally, it is not known if the benefits of resistance training can be augmented by creatine and protein supplementation in older men. Therefore, the purpose of this study was to assess changes in isokinetic parameters at varying speeds in men aged 48 to 72 years (mean=57+/-2.1) following 16 weeks of isotonic resistance training and creatine and/or protein supplementation. METHODS Forty-two male subjects were randomly assigned to 1 of 4 training groups: (1) resistance training placebo (n=10), (2) resistance trained creatine supplemented (n=10), (3) resistance trained protein supplemented (n=11), and (4) resistance trained creatine and protein supplemented (n=11). The program consisted of progressive overload resistance training (3 d/wk) and supplement consumption following the workout. RESULTS There were significant time effects (P>.05) for peak torque (PT), time to PT, and average power for both the knee extensors and flexors at all velocities. However, no significant group or group by time interactions were noted, indicating that the supplementation protocols had no added benefits. CONCLUSIONS Men aged 48 to 72 years maintained their ability to improve isokinetic muscle function following isotonic training, however, supplementation did not enhance muscle adaptability.
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Affiliation(s)
- Jack M Carter
- Department of Health and Exercise Science, University of Oklahoma, Norman Campus, Norman, OK 73019, USA
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Mesa JLM, Ruiz JR, González-Gross MM, Gutiérrez Sáinz A, Castillo Garzón MJ. Oral creatine supplementation and skeletal muscle metabolism in physical exercise. Sports Med 2003; 32:903-44. [PMID: 12427051 DOI: 10.2165/00007256-200232140-00003] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Creatine is the object of growing interest in the scientific literature. This is because of the widespread use of creatine by athletes, on the one hand, and to some promising results regarding its therapeutic potential in neuromuscular disease on the other. In fact, since the late 1900s, many studies have examined the effects of creatine supplementation on exercise performance. This article reviews the literature on creatine supplementation as an ergogenic aid, including some basic aspects relating to its metabolism, pharmacokinetics and side effects. The use of creatine supplements to increase muscle creatine content above approximately 20 mmol/kg dry muscle mass leads to improvements in high-intensity, intermittent high-intensity and even endurance exercise (mainly in nonweightbearing endurance activities). An effective supplementation scheme is a dosage of 20 g/day for 4-6 days, and 5 g/day thereafter. Based on recent pharmacokinetic data, new regimens of creatine supplementation could be used. Although there are opinion statements suggesting that creatine supplementation may be implicated in carcinogenesis, data to prove this effect are lacking, and indeed, several studies showing anticarcinogenic effects of creatine and its analogues have been published. There is a shortage of scientific evidence concerning the adverse effects following creatine supplementation in healthy individuals even with long-term dosage. Therefore, creatine may be considered as a widespread, effective and safe ergogenic aid.
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Affiliation(s)
- José L M Mesa
- Department of Physiology, School of Medicine, University of Granada, Granada, Spain
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Kilduff LP, Vidakovic P, Cooney G, Twycross-Lewis R, Amuna P, Parker M, Paul L, Pitsiladis YP. Effects of creatine on isometric bench-press performance in resistance-trained humans. Med Sci Sports Exerc 2002; 34:1176-83. [PMID: 12131259 DOI: 10.1097/00005768-200207000-00019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this study was to investigate the effects of creatine (Cr) supplementation on force generation during an isometric bench-press in resistance-trained men. METHODS 32 resistance-trained men were matched for peak isometric force and assigned in double-blind fashion to either a Cr or placebo group. Subjects performed an isometric bench-press test involving five maximal isometric contractions before and after 5 d of Cr (20 g.d-1 Cr + 180 g.d-1 dextrose) or placebo (200 g.d-1 dextrose). Body composition was measured before and after supplementation. Subjects completed 24-h urine collections throughout the study period; these were subsequently analyzed to provide total Cr and creatinine excretion. RESULTS The amount of Cr retained over the supplementation period was 45 +/- 18 g (mean +/- SD), with an estimated intramuscular Cr storage of 43 (13-61) mmol x kg(-1) x dry weight muscle (median [range]). Four subjects in the Cr group were classified as "nonresponders" (< or =21 mmol x kg(-1) x dry weight muscle increase following Cr supplementation) and the remaining 17 subjects were classed as "responders" (> or =32 mmol x kg(-1) x dry weight muscle). For the Cr group, peak force and total force pre- or post-supplementation were not different from placebo. However, when the analysis was confined to the responders, both the change in peak force [Repetition 2: 59(81) N vs -26(85) N; Repetition 3: 45(59) N vs -26(64) N) and the change in total force (Repetition 1: 1471(1274) N vs 209(1517) N; Repetition 2: 1575(1254) N vs 196(1413) N; Repetition 3: 1278(1245) N vs -3(1118) N; Repetition 4: 918(935) N vs -83(1095) N] post-supplementation were significantly greater compared with the placebo group (P < 0.01). For the Cr group, estimated Cr uptake was inversely correlated with training status (r = -0.68, N = 21, P = 0.001). Cr significantly increased body weight (84.1 +/- 8.6 kg pre- vs 85.3 +/- 8.3 kg post-supplementation) and fat-free mass (71.8 +/- 6.0 kg pre- vs 72.6 +/- 6.0 kg post-supplementation), with the magnitude of increase being significantly greater in the responder group than in the placebo group. CONCLUSION Five days of Cr supplementation increased body weight and fat-free body mass in resistance-trained men who were classified as responders. Peak force and total force during a repeated maximal isometric bench-press test were also significantly greater in the responders compared to the placebo group.
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Affiliation(s)
- Liam P Kilduff
- Centre for Exercise Science and Medicine, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, UK
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Izquierdo M, Ibañez J, González-Badillo JJ, Gorostiaga EM. Effects of creatine supplementation on muscle power, endurance, and sprint performance. Med Sci Sports Exerc 2002; 34:332-43. [PMID: 11828245 DOI: 10.1097/00005768-200202000-00023] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine the effects of creatine (Cr) supplementation (20 g x d(-1) during 5 d) on maximal strength, muscle power production during repetitive high-power-output exercise bouts (MRPB), repeated running sprints, and endurance in handball players. METHODS Nineteen trained male handball players were randomly assigned in a double-blind fashion to either creatine (N = 9) or placebo (N = 10) group. Before and after supplementation, subjects performed one-repetition maximum half-squat (1RM(HS) and bench press (1RM(BP)), 2 sets of MRPB consisting of one set of 10 continuous repetitions (R10) followed by 1 set until exhaustion (R(max)), with exactly 2-min rest periods between each set, during bench-press and half-squat protocols with a resistance equal to 60 and 70% of the subjects' 1RM, respectively. In addition, a countermovement jumping test (CMJ) interspersed before and after the MRPB half-squat exercise bouts and a repeated sprint running test and a maximal multistage discontinuous incremental running test (MDRT) were performed. RESULTS Cr supplementation significantly increased body mass (from 79.4 +/- 8 to 80 +/- 8 kg; P < 0.05), number of repetitions performed to fatigue, and total average power output values in the R(max) set of MRPB during bench press (21% and 17%, respectively) and half-squat (33% and 20%, respectively), the 1RM(HS) (11%), as well as the CMJ values after the MRPB half-squat (5%), and the average running times during the first 5 m of the six repeated 15-m sprints (3%). No changes were observed in the strength, running velocity, or body mass measures in the placebo group during the experimental period. CONCLUSION Short-term Cr supplementation leads to significant improvements in lower-body maximal strength, maximal repetitive upper- and lower-body high-power exercise bouts, and total repetitions performed to fatigue in the R(max) set of MRPB, as well as enhanced repeated sprint performance and attenuated decline in jumping ability after MRPB in highly trained handball players. Cr supplementation did not result in any improvement in upper-body maximal strength and in endurance running performance.
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Affiliation(s)
- Mikel Izquierdo
- Centro de Investigación y Medicina del Deporte, Gobierno de Navarra, Navarra, Spain.
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Lawler JM, Barnes WS, Wu G, Song W, Demaree S. Direct antioxidant properties of creatine. Biochem Biophys Res Commun 2002; 290:47-52. [PMID: 11779131 DOI: 10.1006/bbrc.2001.6164] [Citation(s) in RCA: 294] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Creatine is the most popular supplement proposed to be an ergogenic aid. There is some evidence in the literature that creatine supplementation increases lean body mass, muscular strength, and sprint power. However, the efficacy of creatine has not been consistent, and the potential mechanisms are unresolved. While limited evidence that suggests that creatine could possess an antioxidant effect this has not been tested directly. Because oxidants such as free radicals can affect muscle fatigue and protein turnover, it is important to know whether creatine can neutralize free radicals and other reactive oxygen species. We tested the hypothesis that creatine would remove superoxide anions (O(*-)(2)), peroxynitrite (OONO-), hydrogen peroxide, and lipid peroxides (t-butyl hydroperoxide). We also determined whether creatine displayed a significant antioxidant scavenging capacity (ASC) using 2,2'-azino-bis(3-ethylbenzothiazolamine-6-sulfonic acid) (ABTS+) quenching as a marker. Creatine did not significantly reduce levels of hydrogen peroxide or lipid peroxidation. In contrast, creatine displayed a significant ability to remove ABTS+, O(*-)(2), and OONO- when compared with controls. Creatine quenching of ABTS+ was less than physiological levels of reduced glutathione (0.375 mM). To our knowledge, this is the first evidence that creatine has the potential to act as a direct antioxidant against aqueous radical and reactive species ions.
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Affiliation(s)
- John M Lawler
- 276-B Read Building, Redox Biology and Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843-4243, USA.
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Bemben MG, Tuttle TD, Bemben DA, Knehans AW. Effects of creatine supplementation on isometric force-time curve characteristics. Med Sci Sports Exerc 2001; 33:1876-81. [PMID: 11689738 DOI: 10.1097/00005768-200111000-00012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess the effects of creatine monohydrate on isometric force-time curve parameters of sedentary college males aged 18-25 yr. METHODS This double-blind study randomly assigned subjects to either a treatment (with creatine (Cr)) group (N = 11) or placebo group (P) (N = 8). The Cr group received 20 g x d(-1) of Cr for the first 5 d, in 5-g doses, four times daily (loading period) followed by a 5-g x d(-1) dose for the next 5 d (maintenance phase) and then no Cr ingestion for 7 d (washout period). Each 5-g dose was mixed with 250 mL of Gatorade. The P group received a placebo (cornstarch) following the exact same dosage regimen and protocol as the Cr group. All subjects were sedentary and had not used any nutritional supplements for 6 months before the study. Measurements of isometric force production of four muscle groups (elbow flexors and extensors; knee flexors and extensors) were characterized by a number of force-time parameters including strength (MF), time to maximal force (TMF), rate of force development (MRFD), and intermittent endurance (total impulse (TI) and percent force decrement (PFD)). Testing was done at pretreatment, after the 10-d loading and maintenance phases, and after the washout phase. RESULTS Repeated measures ANOVA indicated no significant group effect for any muscle group concerning the maximal strength parameters and only two significant time effects for the knee flexors during MF and MRFD. Similarly, there were no significant group effects for any muscle group during the endurance trials; however, there was a significant time effect concerning TI for each muscle group tested. CONCLUSION Our findings indicate that oral supplementation with creatine monohydrate in untrained males does not positively influence isometric strength but may enhance intermittent isometric muscular endurance.
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Affiliation(s)
- M G Bemben
- Neuromuscular Research Lab, Department of Health and Sport Sciences, University of Oklahoma, Norman, OK 73019, USA.
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