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Wax B, Kerksick CM, Jagim AR, Mayo JJ, Lyons BC, Kreider RB. Creatine for Exercise and Sports Performance, with Recovery Considerations for Healthy Populations. Nutrients 2021; 13:1915. [PMID: 34199588 PMCID: PMC8228369 DOI: 10.3390/nu13061915] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/27/2021] [Accepted: 05/30/2021] [Indexed: 02/06/2023] Open
Abstract
Creatine is one of the most studied and popular ergogenic aids for athletes and recreational weightlifters seeking to improve sport and exercise performance, augment exercise training adaptations, and mitigate recovery time. Studies consistently reveal that creatine supplementation exerts positive ergogenic effects on single and multiple bouts of short-duration, high-intensity exercise activities, in addition to potentiating exercise training adaptations. In this respect, supplementation consistently demonstrates the ability to enlarge the pool of intracellular creatine, leading to an amplification of the cell's ability to resynthesize adenosine triphosphate. This intracellular expansion is associated with several performance outcomes, including increases in maximal strength (low-speed strength), maximal work output, power production (high-speed strength), sprint performance, and fat-free mass. Additionally, creatine supplementation may speed up recovery time between bouts of intense exercise by mitigating muscle damage and promoting the faster recovery of lost force-production potential. Conversely, contradictory findings exist in the literature regarding the potential ergogenic benefits of creatine during intermittent and continuous endurance-type exercise, as well as in those athletic tasks where an increase in body mass may hinder enhanced performance. The purpose of this review was to summarize the existing literature surrounding the efficacy of creatine supplementation on exercise and sports performance, along with recovery factors in healthy populations.
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Affiliation(s)
- Benjamin Wax
- Applied Physiology Laboratory, Department of Kinesiology, Mississippi State University, Mississippi State, MS 39759, USA
| | - Chad M. Kerksick
- Exercise & Performance Nutrition Laboratory, College of Science, Technology, and Health, Lindenwood University, St. Charles, MO 63301, USA
| | - Andrew R. Jagim
- Sports Medicine, Mayo Clinic Health System, La Crosse, WI 54601, USA;
| | - Jerry J. Mayo
- Department of Nutrition and Family Sciences, University of Central Arkansas, Conway, AR 72035, USA;
| | - Brian C. Lyons
- Health, Kinesiology, and Sport Management Department, University of Wisconsin—Parkside, Kenosha, WI 53141, USA;
| | - Richard B. Kreider
- Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843, USA;
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Effects of 4-Week Creatine Supplementation Combined with Complex Training on Muscle Damage and Sport Performance. Nutrients 2018; 10:nu10111640. [PMID: 30400221 PMCID: PMC6265971 DOI: 10.3390/nu10111640] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 01/12/2023] Open
Abstract
Creatine supplementation has an ergogenic effect in an acute complex training bout, but the benefits of chronic creatine supplementation during long-term complex training remain unknown. The study aimed to evaluate the effects of 4-week complex training combined with creatine supplementation on sport performances and muscle damage biomarkers. Thirty explosive athletes were assigned to the creatine or placebo group, which consumed 20 g of creatine or carboxymethyl cellulose, respectively, per day for 6 days followed by 2 g of the supplements until the end of the study. After 6 days of supplementation, subjects performed tests of one repetition maximum (1-RM) strength of half squat and complex training bouts to determine the optimal individual post-activation potentiation time. Thereafter, all subjects performed a complex training programme consisting of six sets of 5-RM half squats and plyometric jumps 3 times per week for 4 weeks. Body composition, 30-m sprint and jump performances were assessed before and after the training period. Moreover, blood creatine kinase (CK) activity was analysed at the first and the last training bout. After the training, the 1-RM strength in the creatine group was significantly greater than in the placebo group (p < 0.05). CK activity after the complex training bout in the creatine group was significantly reduced compared with the placebo group (p < 0.05). No differences were noted for other variables. This study concluded that creatine supplementation combined with complex training improved maximal muscular strength and reduced muscle damage during training.
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Myoprotective Potential of Creatine Is Greater than Whey Protein after Chemically-Induced Damage in Rat Skeletal Muscle. Nutrients 2018; 10:nu10050553. [PMID: 29710855 PMCID: PMC5986433 DOI: 10.3390/nu10050553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 12/28/2022] Open
Abstract
The myoprotective effects of creatine monohydrate (CR) and whey protein (WP) are equivocal, with the use of proxy measures of muscle damage making interpretation of their effectiveness limited. The purpose of the study was to determine the effects of CR and WP supplementation on muscle damage and recovery following controlled, chemically-induced muscle damage. Degeneration of the extensor digitorum longus (EDL) muscle was induced by bupivacaine in rats supplemented with either CR, WP, or standard rat chow (CON). At day 7 and 14 post-myotoxic injury, injured EDL muscles were surgically removed and tested for isometric contractile properties, followed by the contralateral, non-injured EDL muscle. At the completion of testing, muscles were snap-frozen in liquid nitrogen and stored for later analysis. Data were analyzed using analysis of variance. Creatine-supplemented muscles displayed a greater proportion of non-damaged (intact) fibers (p = 0.002) and larger cross-sectional areas of regenerating and non-damaged fibers (p = 0.024) compared to CON muscles at day 7 post-injury. At day 14 post-injury, CR-supplemented muscles generated higher absolute forces concomitant with greater contractile protein levels compared to CON (p = 0.001, p = 0.008) and WP-supplemented muscles (p = 0.003, p = 0.006). Creatine supplementation appears to offer an element of myoprotection which was not observed following whey protein supplementation.
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Boychuk KE, Lanovaz JL, Krentz JR, Lishchynsky JT, Candow DG, Farthing JP. Creatine supplementation does not alter neuromuscular recovery after eccentric exercise. Muscle Nerve 2016; 54:487-95. [PMID: 26930603 DOI: 10.1002/mus.25091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 02/16/2016] [Accepted: 02/23/2016] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The purpose of this study was to investigate the effects of creatine (CR) supplementation on recovery after eccentric exercise (ECC). METHODS Fourteen men were assigned randomly to ingest 0.3 g/kg of CR or placebo (PL) before and during recovery (48 hours) from 6 sets of 8 repetitions of ECC. Maximal voluntary contraction (MVC), voluntary activation (VA), muscle thickness (MT), electromyography (EMG), contractile properties, and soreness were assessed. RESULTS MVC, evoked twitch torque, and rate of torque development decreased for both groups immediately after ECC and recovered at 48 hours. MT increased and remained elevated at 48 hours for both groups. Soreness increased similarly for both groups. EMG activation was higher for CR versus PL only at 48 hours. There were no group differences for torque, total work, or fatigue index during ECC. CONCLUSIONS CR supplementation before and during recovery from ECC had no effect on strength, voluntary activation, or indicators of muscle damage. Muscle Nerve 54: 487-495, 2016.
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Affiliation(s)
- Kellie E Boychuk
- College of Kinesiology, University of Saskatchewan, 87 Campus Drive, Saskatoon, Saskatchewan, S7N 5B2, Canada
| | - Joel L Lanovaz
- College of Kinesiology, University of Saskatchewan, 87 Campus Drive, Saskatoon, Saskatchewan, S7N 5B2, Canada
| | - Joel R Krentz
- Department of Physical Education, Faculty of Education, Brandon University, Brandon, Manitoba, Canada
| | - Justin T Lishchynsky
- College of Kinesiology, University of Saskatchewan, 87 Campus Drive, Saskatoon, Saskatchewan, S7N 5B2, Canada
| | - Darren G Candow
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
| | - Jonathan P Farthing
- College of Kinesiology, University of Saskatchewan, 87 Campus Drive, Saskatoon, Saskatchewan, S7N 5B2, Canada
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Kim J, Lee J, Kim S, Yoon D, Kim J, Sung DJ. Role of creatine supplementation in exercise-induced muscle damage: A mini review. J Exerc Rehabil 2015; 11:244-50. [PMID: 26535213 PMCID: PMC4625651 DOI: 10.12965/jer.150237] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/14/2015] [Indexed: 11/22/2022] Open
Abstract
Muscle damage is induced by both high-intensity resistance and endurance exercise. Creatine is a widely used dietary supplement to improve exercise performance by reducing exercise-induced muscle damage. Many researchers have suggested that taking creatine reduces muscle damage by decreasing the inflammatory response and oxidative stress, regulating calcium homeostasis, and activating satellite cells. However, the underlying mechanisms of creatine and muscle damage have not been clarified. Therefore, this review discusses the regulatory effects of creatine on muscle damage by compiling the information collected from basic science and sports science research.
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Affiliation(s)
- Jooyoung Kim
- College of Physical Education, Kookmin University, Seoul, Korea
| | - Joohyung Lee
- College of Physical Education, Kookmin University, Seoul, Korea
| | - Seungho Kim
- Department of Football Management, Munkyung College, Mungyeong, Korea
| | - Daeyoung Yoon
- Department of Football Management, Munkyung College, Mungyeong, Korea
| | - Jieun Kim
- College of Physical Education, Kookmin University, Seoul, Korea
| | - Dong Jun Sung
- Division of Sport Science, Konkuk University, Choongju, Korea
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D'Antona G, Nabavi SM, Micheletti P, Di Lorenzo A, Aquilani R, Nisoli E, Rondanelli M, Daglia M. Creatine, L-carnitine, and ω3 polyunsaturated fatty acid supplementation from healthy to diseased skeletal muscle. BIOMED RESEARCH INTERNATIONAL 2014; 2014:613890. [PMID: 25243159 PMCID: PMC4163371 DOI: 10.1155/2014/613890] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/19/2014] [Accepted: 08/06/2014] [Indexed: 12/22/2022]
Abstract
Myopathies are chronic degenerative pathologies that induce the deterioration of the structure and function of skeletal muscle. So far a definitive therapy has not yet been developed and the main aim of myopathy treatment is to slow the progression of the disease. Current nonpharmacological therapies include rehabilitation, ventilator assistance, and nutritional supplements, all of which aim to delay the onset of the disease and relieve its symptoms. Besides an adequate diet, nutritional supplements could play an important role in the treatment of myopathic patients. Here we review the most recent in vitro and in vivo studies investigating the role supplementation with creatine, L-carnitine, and ω3 PUFAs plays in myopathy treatment. Our results suggest that these dietary supplements could have beneficial effects; nevertheless continued studies are required before they could be recommended as a routine treatment in muscle diseases.
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Affiliation(s)
- Giuseppe D'Antona
- Department of Molecular Medicine and Laboratory for Motor Activities in Rare Diseases (LUSAMMR), University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | - Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, P.O. Box 19395-5487, Tehran, Iran
| | - Piero Micheletti
- Department of Experimental and Forensic Medicine, University of Pavia, Via Forlanini 2, 27100 Pavia, Italy
| | - Arianna Di Lorenzo
- Department of Drug Sciences, Medicinal Chemistry and Pharmaceutical Technology Section, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Roberto Aquilani
- Maugeri Foundation IRCCS, Montescano Scientific Institute, Via Per Montescano 31, 27040 Montescano, Italy
| | - Enzo Nisoli
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy
| | - Mariangela Rondanelli
- Human Nutrition Section, Health Sciences Department, University of Pavia, Azienda di Servizi alla Persona, Via Emilia 12, 27100 Pavia, Italy
| | - Maria Daglia
- Department of Drug Sciences, Medicinal Chemistry and Pharmaceutical Technology Section, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy
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Creatine supplementation enhances muscle force recovery after eccentrically-induced muscle damage in healthy individuals. J Int Soc Sports Nutr 2009; 6:13. [PMID: 19490606 PMCID: PMC2697134 DOI: 10.1186/1550-2783-6-13] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 06/02/2009] [Indexed: 11/23/2022] Open
Abstract
Background Eccentric exercise-induced damage leads to reductions in muscle force, increased soreness, and impaired muscle function. Creatine monohydrate's (Cr) ergogenic potential is well established; however few studies have directly examined the effects of Cr supplementation on recovery after damage. We examined the effects of Cr supplementation on muscle proteins and force recovery after eccentrically-induced muscle damage in healthy individuals. Methods Fourteen untrained male participants (22.1 ± 2.3 yrs, 173 ± 7.7 cm, 76.2 ± 9.3 kg) were randomly separated into 2 supplement groups: i) Cr and carbohydrate (Cr-CHO; n = 7); or ii) carbohydrate (CHO; n = 7). Participants consumed their supplement for a period of 5 days prior to, and 14 days following a resistance exercise session. Participants performed 4 sets of 10 eccentric-only repetitions at 120% of their maximum concentric 1-RM on the leg press, leg extension and leg flexion exercise machine. Plasma creatine kinase (CK) and lactate dehydrogenase (LDH) activity were assessed as relevant blood markers of muscle damage. Muscle strength was examined by voluntary isokinetic knee extension using a Cybex dynamometer. Data were analyzed using repeated measures ANOVA with an alpha of 0.05. Results The Cr-supplemented group had significantly greater isokinetic (10% higher) and isometric (21% higher) knee extension strength during recovery from exercise-induced muscle damage. Furthermore, plasma CK activity was significantly lower (by an average of 84%) after 48 hrs (P < 0.01), 72 hrs (P < 0.001), 96 hrs (P < 0.0001), and 7 days (P < 0.001) recovery in the Cr-supplemented group. Conclusion The major finding of this investigation was a significant improvement in the rate of recovery of knee extensor muscle function after Cr supplementation following injury.
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Abstract
The literature on creatine supplementation supporting its efficacy has grown rapidly and has included studies in both healthy volunteers and patient populations. However, the first rule in the development of therapeutic agents is safety. Creatine is well-tolerated in most individuals in short-term studies. However, isolated reports suggest creatine may be associated with various side effects affecting several organ systems including skeletal muscle, the kidney and the gastrointestinal tract. The majority of clinical studies fail to find an increased incidence of side effects with creatine supplementation. To date, studies have not found clinically significant deviations from normal values in renal, hepatic, cardiac or muscle function. Few data are available on the long-term consequences of creatine supplementation.
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Affiliation(s)
- Adam M Persky
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7360, USA
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Abstract
Excessive or extreme lengthening contractions have a well-characterized depressive effect on skeletal muscle isometric force. In addition to producing force, active muscles must often shorten in order to meet the power requirements of locomotion and other physical activities. However, the impact of lengthening contractions on muscle power is poorly understood. We evaluated the effect of 20 isometric contractions or 20 lengthening contractions (20% strain at 1.5 fiber lengths/s) on the force-velocity-power relationships of mouse soleus muscles in vitro at 35 degrees C. Pre- and posttreatment data were obtained as the muscles shortened through their optimal length (Lo). The isometric treatment did not alter Lo, the curvature of the force-velocity relationship (a/Po), or soleus maximal shortening velocity (Vmax), whereas peak force (Po) displayed a slow, time-dependent decline of 10% across the experiments. Following the lengthening treatment, Lo increased by 6%, a/Po increased by 22%, and Vmax and Po fell by 24% and 26%, respectively. Under optimal conditions for producing power, muscles damaged by lengthening contractions attained 22% less force and shortened 20% more slowly than before damage. Consequently, soleus peak power fell 37% after lengthening, a 2.5-fold greater decline than noted for the isometric treatment. Under the conditions studied here, the excessive power loss following lengthening contractions was due to force and velocity deficits of approximately equal relative magnitude. Because power represents the ability of the muscle to perform work, reductions in both force and shortening velocity should be considered when evaluating and treating lengthening-induced skeletal muscle injuries.
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Affiliation(s)
- Jeffrey J Widrick
- Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, Oregon 97331, USA.
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Warren GL, O'farrell L, Rogers KR, Billings KM, Sayers SP, Clarkson PM. CK-MM autoantibodies: Prevalence, immune complexes, and effect on CK clearance. Muscle Nerve 2006; 34:335-46. [PMID: 16810680 DOI: 10.1002/mus.20594] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although the blood level of creatine kinase (CK) is the most commonly used marker of muscle injury, there is marked interindividual variability in this measure. Part of this variability may be attributed to variability in the rate of CK clearance from the circulation. In this study, we assessed the possibility that CK-MM autoantibodies form immune complexes with CK following muscle injury and subsequently affect the CK clearance rate. Using an enzyme-linked immunosorbent assay, CK-MM autoantibodies were detected in all 25 human subjects studied but the levels varied greatly. Using protein A-sepharose, the percentage of the plasma CK activity found in immune complexes was determined to be correlated with the CK-MM autoantibody level at lower CK levels (<1,022 U/L). When CK-MM antibodies were administered to mice, plasma CK activity following a bolus CK injection was reduced by 11%-32%. We conclude that CK-MM autoantibodies can modulate the rate of CK clearance from the circulation. Thus, the relatively low blood CK levels seen in some individuals following injury may be attributed partly or entirely to an autoantibody-enhanced clearance of CK.
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MESH Headings
- Adult
- Animals
- Antigen-Antibody Complex/immunology
- Autoantibodies/blood
- Autoantibodies/immunology
- Creatine Kinase, MM Form/blood
- Creatine Kinase, MM Form/immunology
- Female
- Humans
- Interleukin-6/genetics
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/immunology
- Muscle, Skeletal/injuries
- Myositis/immunology
- Myositis/metabolism
- Nervous System Autoimmune Disease, Experimental/immunology
- Nervous System Autoimmune Disease, Experimental/metabolism
- Receptors, CCR2
- Receptors, CCR5/genetics
- Receptors, Chemokine/genetics
- Seroepidemiologic Studies
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Affiliation(s)
- Gordon L Warren
- Division of Physical Therapy, Georgia State University, Atlanta, Georgia 30302, USA.
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Byrne C, Twist C, Eston R. Neuromuscular function after exercise-induced muscle damage: theoretical and applied implications. Sports Med 2004; 34:49-69. [PMID: 14715039 DOI: 10.2165/00007256-200434010-00005] [Citation(s) in RCA: 320] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Exercise-induced muscle damage is a well documented phenomenon particularly resulting from eccentric exercise. When eccentric exercise is unaccustomed or is performed with an increased intensity or duration, the symptoms associated with muscle damage are a common outcome and are particularly associated with participation in athletic activity. Muscle damage results in an immediate and prolonged reduction in muscle function, most notably a reduction in force-generating capacity, which has been quantified in human studies through isometric and dynamic isokinetic testing modalities. Investigations of the torque-angular velocity relationship have failed to reveal a consistent pattern of change, with inconsistent reports of functional change being dependent on the muscle action and/or angular velocity of movement. The consequences of damage on dynamic, multi-joint, sport-specific movements would appear more pertinent with regard to athletic performance, but this aspect of muscle function has been studied less often. Reductions in the ability to generate power output during single-joint movements as well as during cycling and vertical jump movements have been documented. In addition, muscle damage has been observed to increase the physiological demand of endurance exercise and to increase thermal strain during exercise in the heat. The aims of this review are to summarise the functional decrements associated with exercise-induced muscle damage, relate these decrements to theoretical views regarding underlying mechanisms (i.e. sarcomere disruption, impaired excitation-contraction coupling, preferential fibre type damage, and impaired muscle metabolism), and finally to discuss the potential impact of muscle damage on athletic performance.
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Affiliation(s)
- Christopher Byrne
- Centre for Human Performance, Defence Medical and Environmental Research Institute, DSO National Laboratories, Republic of Singapore
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Rathbone CR, Wenke JC, Warren GL, Armstrong RB. Importance of satellite cells in the strength recovery after eccentric contraction-induced muscle injury. Am J Physiol Regul Integr Comp Physiol 2003; 285:R1490-5. [PMID: 12920057 DOI: 10.1152/ajpregu.00032.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to determine if the elimination of satellite cell proliferation using gamma-irradiation would inhibit normal force recovery after eccentric contraction-induced muscle injury. Adult female ICR mice were implanted with a stimulating nerve cuff on the common peroneal nerve and assigned to one of four groups: 1) irradiation- and eccentric contraction-induced injury, 2) eccentric contraction-induced injury only, 3) irradiation only, and 4) no intervention. Anterior crural muscles were irradiated with a dose of 2,500 rad and injured with 150 in vivo maximal eccentric contractions. Maximal isometric torque was determined weekly through 35 days postinjury. Immediately after injury, maximal isometric torque was reduced by approximately 50% and had returned to normal by 28 days postinjury in the nonirradiated injured mice. However, torque production of irradiated injured animals did not recover fully and was 25% less than that of injured nonirradiated mice 35 days postinjury. These data suggest that satellite cell proliferation is required for approximately half of the force recovery after eccentric contraction-induced injury.
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Affiliation(s)
- Christopher R Rathbone
- Depatment of Health and Kinesiology, Texas A&M University, College Station, Texas 7784, USA
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Phillips T, Childs AC, Dreon DM, Phinney S, Leeuwenburgh C. A Dietary Supplement Attenuates IL-6 and CRP after Eccentric Exercise in Untrained Males. Med Sci Sports Exerc 2003; 35:2032-7. [PMID: 14652498 DOI: 10.1249/01.mss.0000099112.32342.10] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study investigated the effects of a dietary supplement on exercise-induced markers of cell damage and the inflammatory mediators C-reactive protein (CRP) and interleukin-6 (IL-6). METHODS The supplement contained mixed tocopherols, flavonoids, and docosahexaenoate. Forty healthy, nonsmoking, untrained males (aged 18-35 yr) were randomly assigned to receive either the supplement (N = 20) or placebo (N = 20) during the 14-d experimental protocol. Blood samples were collected on day 0 (baseline), day 7 (eccentric exercise-induced injury), day 10, and day 14. OBJECTIVE Markers of cell damage (creatine kinase (CK) and lactate dehydrogenase (LDH)) and inflammation IL-6 and CRP were assessed at these time points in conjunction with subjective range of motion (ROM) and perceived pain measurements. Statistical analyses were conducted using nonparametric methods (P < 0.05). RESULTS Eccentric arm curl exercise was used to induce an acute phase injury response as evidenced by significant (P < 0.0001) increases in CK, LDH, and pain, as well as a decreased range of motion 3 d after the exercise. There were no significant differences between groups in CK and LDH responses. In contrast, there were significant group differences for IL-6 (P = 0.008) and CRP (P = 0.003). At day 10, by Mann-Whitney U test of changes, the placebo group had significantly greater increases in IL-6 and CRP than the treatment group (P = 0.05 and P < 0.01), respectively. CONCLUSION This study suggested that exercise-induced inflammation, evaluated by changes in IL-6 and CRP, was significantly reduced by the dietary supplement.
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Affiliation(s)
- Tracey Phillips
- University of Florida, Biochemistry of Aging Laboratory, College of Health and Human Performance, Center for Exercise Science, College of Medicine, Gainesville 32611, USA
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