Article

Effects of Varying Dosages of Oral Creatine Relative to Fat Free Body Mass on Strength and Body Composition

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Abstract

This study compared the effects of different dosages of creatine relative to fat free mass on strength, % body fat, body mass (BM), fat free mass (FFM), 40-yd dash time, and vertical jump (VJ) height. In a true experimental double-blind design, 39 male college athletes were given either 5 g creatine mono-hydrate or a placebo 4 times a day for 5 days. For the rest of the 8 weeks they were given either a placebo or 100 or 300 mg * kg-1 FFM of creatine. During this period all subjects undertook a conditioning program 4 times a week emphasizing weight training and speed drills. Pre- and posttesting was conducted on all 6 variables. Both experimental groups had significant improvements in the bench press; the group ingesting 300 mg * kg-1 FFM of creatine improved significantly more than the control group (p < 0.05). Forty-yard dash improvement was significantly better as a result of ingesting 100 mg * kg-1 FFM of creatine compared to the control group. Only the 100-mg group significantly improved 40-yd time. No significant differences among groups were noted in BM, % body fat, FFM, or VJ. In conclusion, ingestion of 100 or 300 mg * kg-1 FFM of creatine for 8 weeks in conjunction with weight training and speed training significantly improved 40-yd dash time and bench press strength, respectively. (C) 1998 National Strength and Conditioning Association

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... Oral supplementation with creatine monohydrate (CM) has been shown to increase muscle strength and performance during both acute and chronic supplementation protocols (10,15,17,18,22,31). Most previous investigations have examined the effects of chronic creatine supplementation in conjunction with a structured resistance training regimen (3,19,23,25,26,28,30). For example, Willoughby and Rosene (32) reported an increase in leg extension 1 repetition maximum (1RM) strength after 12 weeks of resistance training combined with CM supplementation (26 gÁd 21 for 1 week and 6 gÁd 21 for the remaining 11 weeks). ...
... Several previous investigations (23,25,26,28,29,32) have demonstrated increases in muscular strength (i.e., 1RM) after CM supplementation. In the present study, 1RM BP and 1RM LP increased for all creatine groups (CM, PEG 1.25 , and PEG 2.50 ) after supplementation. ...
... In the present study, 1RM BP and 1RM LP increased for all creatine groups (CM, PEG 1.25 , and PEG 2.50 ) after supplementation. A unique aspect of this study was that subjects were allowed to maintain their current exercise schedule and did not perform a structured resistance training regimen like previous investigations (3,4,19,23,26). In addition, the daily dose of creatine consumed by the PEG groups (1.25 g and 2.50 g) was considerably less than that used in previous investigations that reported similar increases (26,28,29,32) in muscular strength. For example, several studies (25,26,29) have reported increases in muscular strength after a CM supplementation period that consisted of an initial loading period of 20 gÁd 21 , followed by a maintenance period of 5-10 gÁd 21 for the remainder of the supplementation period. ...
Article
The purpose of this study was to examine the effects of a moderate dose of creatine monohydrate (CM) and two smaller doses of polyethylene glycosylated (PEG) creatine on muscular strength, endurance, and power output. Fifty-eight healthy men (mean +/- SD: age, 21 +/- 2 years; height, 176 +/- 6 cm; body mass [BM], 75 +/- 14 kg) volunteered and were randomly assigned to 1 of 4 groups: (a) placebo (PL; 3.6 g of microcrystalline cellulose; n = 15), (b) CM (5 g of creatine; n = 13), (c) small-dose PEG creatine (1.25 g of creatine: PEG1.25; n = 14), or (d) moderate-dose PEG creatine (2.50 g of creatine: PEG2.50; n = 16). Testing was conducted before (pre-) and after (post-) a 30-day supplementation period. Measurements included body mass, countermovement vertical jump (CVJ) height, power output during the Wingate test (peak power [PP] and mean power [MP]), 1 repetition maximum bench press (1RMBP), 1RM leg press (1RMLP) strength, and repetitions to failure at 80% of the 1RM for bench press (REPBP) and leg press (REPLP). BM and MP (W) increased (p <or= 0.05) from pre- to postsupplementation for the CM group only, whereas 1RMBP and 1RMLP increased (p <or= 0.05) for the CM, PEG1.25, and PEG2.50 groups. CVJ height (cm and cm.kg), MP (W.kg), PP (W and W.kg), REPBP, and REPLP increased (p <or= 0.05) for all groups. These findings indicated that the recommended safe dose of 5 g.d of CM increased BM and improved muscle strength (1RMBP and 1RMLP). Smaller doses of PEG creatine (1.25 and 2.50 g.d) improved muscle strength (1RMBP and 1RMLP) to the same extent as 5 g.d of CM, but did not alter BM, power output, or endurance. When compared to the PL group, neither CM nor PEG creatine supplementation improved peak power output (CVJ or PP), MP, or muscle endurance (REPBP or REPLP). Thus, PEG creatine may have ergogenic effects that are comparable to those of CM, but with a smaller dose of creatine.
... In contrast, many have observed a mean 0.6-to 1.7-kg increase in body mass in Cr-supplemented subjects (11,16). However, an increase in body mass during short-term Cr supplementation is not a universal finding (5,23), even when an increase in muscle total Cr is confirmed following Cr supplementation (21). Furthermore, most studies that report greater mass gain following Cr supplementation than Pla treatment have incorporated resistance training into the experimental intervention or used subjects who continued their own resistance training program during the study (1,5,10,12,15,31). ...
... The failure of Cr supplementation to affect measures of muscle performance may also reflect the absence of a resistance training stimulus during the supplementation period. The most consistent performance-enhancing effects of Cr supplementation have been reported when Cr was combined with resistance-type exercise training (1,5,15,23,31,33). Almost all of the strength studies included in the metaanalysis of Dempsey and colleagues (4), who found a benefit of Cr supplementation using maximal weight lifted as an outcome variable and studied young, previously trained men undergoing resistance training during the supplementation period. ...
... In contrast, many have observed a mean 0.6-to 1.7-kg increase in body mass in Cr-supplemented subjects (11,16). However, an increase in body mass during short-term Cr supplementation is not a universal finding (5,23), even when an increase in muscle total Cr is confirmed following Cr supplementation (21). Furthermore, most studies that report greater mass gain following Cr supplementation than Pla treatment have incorporated resistance training into the experimental intervention or used subjects who continued their own resistance training program during the study (1,5,10,12,15,31). ...
... The failure of Cr supplementation to affect measures of muscle performance may also reflect the absence of a resistance training stimulus during the supplementation period. The most consistent performance-enhancing effects of Cr supplementation have been reported when Cr was combined with resistance-type exercise training (1,5,15,23,31,33). Almost all of the strength studies included in the metaanalysis of Dempsey and colleagues (4), who found a benefit of Cr supplementation using maximal weight lifted as an outcome variable and studied young, previously trained men undergoing resistance training during the supplementation period. ...
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To determine whether creatine (Cr) supplementation improves muscle performance during exposure to acute hypobaric hypoxia. Seven healthy men (28 +/- 6 yr, mean +/- SD) performed submaximal intermittent static knee contractions interspersed with maximal voluntary contractions (MVCs) every minute to exhaustion (approximately 50% of rested MVC force) in normoxia and hypobaric hypoxia (separated by 3 d) after supplementation with Cr (20 g.d(-1) for 7 d then 5 g.d(-1) for 4-7 d) or placebo (Pla) in a double-blind, randomized crossover study. A 5-wk period without supplementation separated treatments. Each test day, subjects performed two bouts (separated by 2 min) at their preset submaximal force, 32 +/- 4% rested MVC). Rested MVC force (860 +/- 66 N) and MVC force at exhaustion (396 +/- 27 N; 47 +/- 3% rested MVC) did not differ among treatments or environments (P > 0.05). For bout 1, endurance time was shorter in hypobaria (26 +/- 3 min) than normoxia (34 +/- 2 min) (P < 0.01), but did not differ between Cr (27 +/- 3 min) and Pla (33 +/- 3 min) (P > 0.05). MVC force returned to similar levels (P >0.05) in bout 2 after recovery in all four sessions (to approximately 615 N). For bout 2, endurance time also was shorter in hypobaria (7 +/- 1 min) than normoxia (9 +/- 1 min) (P < 0.03) but did not differ between Cr and Pla (P > 0.05). This study, which used an exercise model designed to impose the same target contraction force under all experimental conditions, found no effect of Cr on maximal force, muscle endurance, or recovery in normoxia or hypobaric hypoxia.
... Three resistance training studies (19,21,30) found increases in body mass and fat-free mass and one (25) found no change. Despite an abundance of studies, only four studies (19,21,25,30 ) have examined the effects of creatine supplementation while strength training. Only two of these studies (25,30) reported changes in 1RM, a criterion measure of muscular strength. ...
... However , in a comparison of the magnitude of the strength gains, the Cr increase was 11.8% greater than Placebo. These data agree with the two studies (9,31) that showed increased muscular strength with short-term creatine supplementation and the four studies (19,21,25,30 ) that showed greater increases in muscular strength with creatine supplementation while resistance training. In particular, our data extend the work of Vanderberghe et al. (30) with novice females and Kreider et al. (21) and Noonan et al. (25) with experienced football players to experienced male weight lifters. ...
Article
The purpose of this investigation was to examine the effects of 6 wk of oral creatine supplementation during a periodized program of arm flexor strength training on arm flexor IRM, upper arm muscle area, and body composition. Twenty-three male volunteers with at least 1 yr of weight training experience were assigned in a double blind fashion to two groups (Cr, N = 10; Placebo, N = 13) with no significant mean pretest one repetition maximum (IRM) differences in arm flexor strength. Cr ingested 5 g of creatine monohydrate in a flavored, sucrose drink four times per day for 5 d. After 5 d, supplementation was reduced to 2 g x d(-1). Placebo ingested a flavored, sucrose drink. Both drinks were 500 mL and made with 32 g of sucrose. IRM strength of the arm flexors, body composition, and anthropometric upper arm muscle area (UAMA) were measured before and after a 6-wk resistance training program. Subjects trained twice per week with training loads that began at 6RM and progressed to 2RM. IRM for Cr increased (P < 0.01) from (mean +/- SD) 42.8 +/- 17.7 kg to 54.7 +/- 14.1 kg, while IRM for Placebo increased (P < 0.01) from 42.5 +/- 15.9 kg to 49.3 +/- 15.7 kg. At post-test IRM was significantly (P < 0.01) greater for Cr than for Placebo. Body mass for Cr increased (P < 0.01) from 86.7 +/- 14.7 kg to 88.7 +/- 13.8 kg. Fat-free mass for Cr increased (P < 0.01) from 71.2 +/- 10.0 kg to 72.8 +/- 10.1 kg. No changes in body mass or fat-free mass were found for Placebo. There were no changes in fat mass and percent body fat for either group. UAMA increased (P < 0.01) 7.9 cm2 for Cr and did not change for Placebo. Creatine supplementation during arm flexor strength training lead to greater increases in arm flexor muscular strength, upper arm muscle area, and fat-free mass than strength training alone.
... These results confirm previous findings observed in our laboratory with highly trained soccer players (27) and others with handball players (1) and suggest that Cr supplementation provides a potential benefit in energy provision during very short-term, high-intensity exercise, especially when performed in repeated succession. However, these results differ from other studies in which no ergogenic effects (22,31,32) or mixed effects (29,34) were found on sprint running performance after Cr supplementation. The conflicting results between studies regarding the effects of Cr supplementation on sprint running performance could be attributed to differences in the amount of repetitions and frames or distances tested. ...
... The conflicting results between studies regarding the effects of Cr supplementation on sprint running performance could be attributed to differences in the amount of repetitions and frames or distances tested. Indeed, the studies that have found no effects or mixed effects of acute Cr loading tested sprint running performance with only a single bout (22,29,34) or with repeated bouts of distances greater than 15 m (31,32). As mentioned previously, a clearer improvement in sprint performance after Cr loading should be expected during repeated short supramaximal exercise of 1-to 2-s duration because: 1) during this time frame, PCr generates the highest peak rates of ATP production (13); 2) PCr availability is critical for power generation during the initial seconds of exercise (6); and 3) Cr loading may increase the rate of PCr resynthesis during recovery periods after muscle contractions (11,13). ...
Article
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. 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. 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. 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.
... BARNETT et al., 1996 REDONDO et al., 1996; GRINDSTAFF et al., 1997; HAMILTON-WARD et al., 1997; PREVOST et al., 1997; TERRILLION et al., 1997; McKENNA et al., 1999; STOUT et al., 1999; ROSSOUW et al., 2000; FRANCAUX et al., 2000; PARISE et al., 2001; DAWSON et al., 2002; HUSO et al., 2002; WILDER et al., 2002. Longo prazo (crônica) VANDENBERGHE et al., 1997; KELLY & JENKINS, 1998; KNEHANS et al., 1998a;; NOOMAN et al., 1998;FRANCAUX E POORTMANS, 1999; PEETERS et al., 1999; STONE et al., 1999; VOLEK et al., 1999; VUKOVICH & MICHAELIS, 1999; BECQUE et al., 2000; VOLEK et al., 2000; BEMBEN et al., 2001; BURKE et al., 2001; FONTANA, 2003; ROGERS et al., 2006. EARNEST et al., 1995 THOMPSON et al., 1996; BERMON et al., 1998; LARSON et al., 1998; SYROTUIK et al., 2001 BARROS, 1999; MELBY et al, 1993; POLLOCK et al, 2000). ...
Article
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, 2008. A creatina como suplementação nutricional tem se popularizado e sido indiscriminadamente utilizada por apresentar ganho de massa magra e melhora do desempenho de atividades que envolvam exercícios de curta duração e alta intensidade. Porém, as intercorrências advindas do seu uso não estão totalmente elucidadas. Os efeitos adversos, principalmente em relação à sobrecarga renal e/ou hepática, foram tratados neste estudo através de avaliações bioquímicas sobre uma amostra de 35 desportistas divididos em três grupos de consumo (PLA: placebo, CRE1: 0,03g de creatina por kg de massa corporal por dia e CRE2: 5g de creatina por dia) durante oito semanas de treinamento. Os voluntários foram avaliados, através de medidas antropométricas, quanto ao ganho de massa magra e composição corporal. Para avaliação da composição corporal utilizou-se o protocolo de sete dobras e os perímetros de braço e coxa. Os participantes foram submetidos a um programa de treinamentocom exercícios resistidos constituídos de três séries, variando entre 8 a 12 repetições em cada série, com intervalo de um minuto, quatro ou mais vezes por semana e não sofreram intervenção na composição de suas dietas, que foram registradas e analisadas. Houve ganho ponderal, de 2,1% (CRE1) e 3,5% (CRE2) e a massa corporal magra aumentou significativamente entre os grupos PLA–CRE1 e PLA–CRE2 (P<0,01). Entre o PRÉ e o PÓStreinamento foi registrado aumento das circunferências de braço tenso, coxa, circunferência muscular do braço e da perna e índice de massa magra do braço nos tratamentos CRE1 e CRE2 (P<0,01). Todos os resultados dos exames bioquímicos realizados permaneceram dentro das faixas de normalidade. Quanto à função renal a creatinina aumentou significativamente nos grupos suplementados com creatina, porém sem sair dos valores de normalidade. Os valores dos exames da função hepática diminuíram em quase todas as frações, em todos os tratamentos, entretanto sem significância estatística. Estes resultados contribuíram no esclarecimento dos efeitos advindos do uso de creatina, permitindo o uso mais seguro deste suplemento nutricional. Concluiu-se que ocorreu ganho de massa magra para os grupos suplementados com creatina, independentemente das dosagens oferecidas, e de forma segura, não encontrando efeitos adversos nas funções hepáticas e renais. _________________________________________________________________________________________ ABSTRACT The use of creatine as nutritional supplement has become popular and has been widely used because of its effect on mass gain and as a performance-enhancing supplement on short duration, high intensity exercises. The intercurrence of its usage has yet to be clarified. The adverse effects, especially in relation to kidney and liver overload, were treated on this study through biochemical analysis on 35 volunteers, divided in 3 study groups (PLA: Placebo, CRE1:daily ingestion 0,03g creatine/kg of bodyweight, CRE2: daily ingestion of 5g creatine/kg of bodyweight) during a 8 week period. The volunteers were submitted to anthropometric measurements in relation to muscle mass and body composition (skinfolds, arm and anterior thigh circumferences). The volunteers were in a resistance exercise program and did not have a dietary change (observed). The exercise program consisted in 3 sets, with 8 to 12 repetitions each, and a minute break between sets, 4 times a week. The overall gain was of 2.1% (CRE1) and 3.5% (CRE2) and the fat-free mass gain was significant among the supplemented groups compare to placebo (P<0.01). Between the pre and post treatments an increase in the arm and leg circumferences in both treatments CRE1 and CRE2 was found (P<0.01). All the biochemical tests made throughout the study were within the normality range. The kidney function had a significant increase with the creatine but without being abnormal. In relation to the liver function, it presented lower performance in all treatments without statistical significance. The results contributed to the enlightment on the usage of creatine supplementation allowing a safer use. In conclusion the fat-free mass increased in creatine supplemented groups, independent of the dosage used and in a safe manner without adverse affects on liver and kidney functions.
... (Takashi Abe et al., 2000) (Cribb, Williams, Carey, & Hayes, 2006) (Joy et al., 2016) (Naclerio, Seijo-Bujia, Larumbe-Zabala, & Earnest, 2017) (Taylor et al., 2011) (T. Abe, K. Kojima, C. F. Kearns, H. Yohena, & J. Fukuda, 2003) (Cribb, Williams, Stathis, Carey, & Hayes, 2007) (Kalman, Feldman, Martinez, Krieger, & Tallon, 2007) (Noonan, Berg, Latin, Wagner, & Reimers, 1998) (Juha P. Ahtiainen et al., 2011) ( ...
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... More recently, Cr supplementation was also found to be able to stimulate protein synthesis [24] and to reduce exercise induced muscle damage [25]. Most studies with the Cr dose and treatment period comparable to that used presently reported gains in strength and power as measured by one-repetition maximum, (1-RM), vertical jump, and 40-year dash in subjects who resistance trained [26][27][28][29]. These studies also observed an increase in FFM presumably due to fluid retention because CrM can draw water into the intracellular compartment via osmosis [26,[28][29]. ...
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The present study examined the effect of simultaneous ingestion of whey protein (WP) and creating monohydrate (CrM) on body composition, selected measures of muscular strength and power, and risks for potential renal dysfunction. Fifteen professional athletes including nine males and six females specialized in track and field, Olympic weight lifting, and modern pentathlon volunteered to participate in the study. Subjects underwent a four-week treatment period during which they ingested both (WP) and CrM while maintaining their regular diet and training intensity and volume. Body composition and performance of one-min pull-up, one-min push up, one-min squat-to-stand, standing long jump, triple jump, and 30-s single leg lateral jumps were measured before and after the treatment. Urine samples were collected throughout the treatment to determine albumin and creatinine concentrations. No changes in body weight, muscle mass, and % body fat were noted following the treatment. The treatment, however, improved (p < 0.05) scores in one-min pull-up, one-min push up, one-min squat-to-stand, triple jump, 30-s single leg lateral jump tests. No differences in urinary albumin and creatinine were found throughout the treatment period. In conclusion, co-supplementation of WP and CrM for four weeks is an effective yet safe ergogenic strategy in enhancing strength and power in professional athletes.
... Only 38 studies had a maintenance dose, which varied between 1.25 and 27.0 g/day [23,27]. The quantity of the maintenance dose varied more between studies compared with the loading dose. ...
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Background Creatine is the most widely used supplementation to increase performance in strength; however, the most recent meta-analysis focused specifically on supplementation responses in muscles of the lower limbs without regard to upper limbs. Objective We aimed to systematically review the effect of creatine supplementation on upper 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 measured in exercises shorter than 3 min in duration. The search strategy used the keywords ‘creatine’, ‘supplementation’, and ‘performance’. Independent variables were age, sex and level of physical activity at baseline, while dependent variables were creatine loading, total dose, duration, time interval between baseline (T0) and the end of the supplementation (T1), and any training during supplementation. We conducted three meta-analyses: at T0 and T1, and on changes between T0 and T1. Each meta-analysis was stratified within upper limb muscle groups. Results We included 53 studies (563 individuals in the creatine supplementation group and 575 controls). Results did not differ at T0, while, at T1, the effect size (ES) for bench press and chest press were 0.265 (95 % CI 0.132–0.398; p < 0.001) and 0.677 (95 % CI 0.149–1.206; p = 0.012), respectively. Overall, pectoral ES was 0.289 (95 % CI 0.160–0.419; p = 0.000), and global upper limb ES was 0.317 (95 % CI 0.185–0.449; p < 0.001). Meta-analysis of changes between T0 and T1 gave similar results. The meta-regression showed no link with characteristics of population or supplementation, demonstrating the efficacy of creatine independently of all listed conditions. Conclusion Creatine supplementation is effective in upper limb strength performance for exercise with a duration of less than 3 min, independent of population characteristics, training protocols, and supplementary doses or duration.
... In several of our performance measures, creatine supplementation generally resulted in improved performance responses to the overreaching protocol [i.e., maintenance of muscular performance during the highvolume phase, a statistically greater improvement in the ballistic bench press peak power output, and a tendency (P=0.09) for a greater improvement in week squat]. Several other studies have reported that creatine supplementation augments gains in muscular after resistance training programs lasting 3 weeks (Burke et al. 2000), 4 weeks (Arciero et al. 2001; Earnest et al. 1995; Kelly and Jenkins 1998; Kreider et al. 1998), 5 weeks (Stone et al. 1999), 6 weeks (Burke et al. 2001), 8 weeks (Noonan et al. 1998), 9 weeks (Bemben et al. 2001), 10 weeks (Vandenberghe et al. 1997), 12 weeks (Volek et al. 1999), and 13 weeks (Larson-Meyer et al. 2000). Unique to this study, the same muscle groups were trained 5 days in a row, thus reducing the amount of recovery time between workouts to less than 24 h. ...
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To determine the effects of creatine supplementation during short-term resistance training overreaching on performance, body composition, and resting hormone concentrations, 17 men were randomly assigned to supplement with 0.3 g/kg per day of creatine monohydrate (CrM: n=9) or placebo (P: n=8) while performing resistance exercise (5 days/week for 4 weeks) followed by a 2-week taper phase. Maximal squat and bench press and explosive power in the bench press were reduced during the initial weeks of training in P but not CrM. Explosive power in the bench press, body mass, and lean body mass (LBM) in the legs were augmented to a greater extent in CrM ( P<or=0.05) by the end of the 6-week period. A tendency for greater 1-RM squat improvement ( P=0.09) was also observed in CrM. Total testosterone (TT) and the free androgen index (TT/SHBG) decreased in CrM and P, reaching a nadir at week 3, whereas sex hormone binding globulin (SHBG) responded in an opposite direction. Cortisol significantly increased after week 1 in CrM (+29%), and returned to baseline at week 2. Insulin was significantly depressed at week 1 (-24%) and drifted back toward baseline during weeks 2-4. Growth hormone and IGF-I levels were not affected. Therefore, some measures of muscular performance and body composition are enhanced to a greater extent following the rebound phase of short-term resistance training overreaching with creatine supplementation and these changes are not related to changes in circulating hormone concentrations obtained in the resting, postabsorptive state. In addition, creatine supplementation appears to be effective for maintaining muscular performance during the initial phase of high-volume resistance training overreaching that otherwise results in small performance decrements.
... Few data exist on the long-term benefits and risks of Cr supplementation in men and women. A number of studies indicate that Cr supplementation in conjunction with heavy-resistance exercise training (e.g., 4 -12 wk in duration) enhances the normal physiological adaptations to the weight-training program (51,55,66,73,108,112). Typical training adaptations, including increases in body mass, fat-free mass, maximal strength and power, lifting volume, and muscle fiber hypertrophy (73,108,112), are all significantly enhanced concurrent with Cr supplementation. ...
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Creatine (Cr) supplementation has become a common practice among professional, elite, collegiate, amateur, and recreational athletes with the expectation of enhancing exercise performance. Research indicates that Cr supplementation can increase muscle phosphocreatine (PCr) content, but not in all individuals. A high dose of 20 g x d(-1) that is common to many research studies is not necessary, as 3 g x d(-1) will achieve the same increase in PCr given time. Coincident ingestion of carbohydrate with Cr may increase muscle uptake; however, the procedure requires a large amount of carbohydrate. Exercise performance involving short periods of extremely powerful activity can be enhanced, especially during repeated bouts of activity. This is in keeping with the theoretical importance of an elevated PCr content in skeletal muscle. Cr supplementation does not increase maximal isometric strength, the rate of maximal force production, nor aerobic exercise performance. Most of the evidence has been obtained from healthy young adult male subjects with mixed athletic ability and training status. Less research information is available related to the alterations due to age and gender. Cr supplementation leads to weight gain within the first few days, likely due to water retention related to Cr uptake in the muscle. Cr supplementation is associated with an enhanced accrual of strength in strength-training programs, a response not independent from the initial weight gain, but may be related to a greater volume and intensity of training that can be achieved. There is no definitive evidence that Cr supplementation causes gastrointestinal, renal, and/or muscle cramping complications. The potential acute effects of high-dose Cr supplementation on body fluid balance has not been fully investigated, and ingestion of Cr before or during exercise is not recommended. There is evidence that medical use of Cr supplementation is warranted in certain patients (e.g.. neuromuscular disease); future research may establish its potential usefulness in other medical applications. Although Cr supplementation exhibits small but significant physiological and performance changes, the increases in performance are realized during very specific exercise conditions. This suggests that the apparent high expectations for performance enhancement, evident by the extensive use of Cr supplementation, are inordinate.
... Conversely, creatine supplementation may prove to be a safe and effective over-the-counter means to diminish age-related declines in muscle mass and strength as research has found creatine supplementation to increase strength[6] and type II muscle fiber diameter[7] independent of exercise. Moreover, creatine supplementation has repeatedly been found to increase performance in younger (≤ 35 yr)89101112131415 adults, particularly when consumed in conjunction with a resistance training regimen. However, studies examining the effects of creatine supplementation in older adults (> 55 yr) have yielded apparently equivocal results1617181920212223242526. ...
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Creatine supplementation has been found to significantly increase muscle strength and hypertrophy in young adults (</= 35 yr) particularly when consumed in conjunction with a resistance training regime. Literature examining the efficacy of creatine supplementation in older adults (55-82 yr) suggests creatine to promote muscle strength and hypertrophy to a greater extent than resistance training alone. The following is a review of literature reporting on the effects of creatine supplementation on intramuscular high energy phosphates, skeletal muscle morphology and quality of life in older adults. Results suggest creatine supplementation to be a safe, inexpensive and effective nutritional intervention, particularly when consumed in conjunction with a resistance training regime, for slowing the rate of muscle wasting that is associated with aging. Physicians should strongly consider advising older adults to supplement with creatine and to begin a resistance training regime in an effort to enhance skeletal muscle strength and hypertrophy, resulting in enhanced quality of life.
... L'alimentation reste un acteur majeur de la croissance musculaire: sans apports nutritionnels pas de reconstruction ni de surcompensation musculaire. Cette évidence semble admise par tous au vu du peu d'expérimentations retrouvées dans la littérature en dehors de celles traitant de l'utilisation de créatine [95][96][97] . Seuls certains auteurs prennent le soin d'évaluer l'alimentation des sujets et d'augmenter les apports dans le cadre de l'étude [14] mais ils ne prennent pas en compte le moment où les nutriments sont ingérés. ...
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System requirements: World Wide Web browser and PDF reader. Mode of access: Available through the Internet. Title from document title page. Document formatted into pages; contains xii, 156 p. : ill. (some col.). Thesis (Ph. D.)--West Virginia University, 2003. Includes abstract. Includes bibliographical references.
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Creatine has become a popular nutritional supplement among athletes. Recent research has also suggested that there may be a number of potential therapeutic uses of creatine. This paper reviews the available research that has examined the potential ergogenic value of creatine supplementation on exercise performance and training adaptations. Review of the literature indicates that over 500 research studies have evaluated the effects of creatine supplementation on muscle physiology and/or exercise capacity in healthy, trained, and various diseased populations. Short-term creatine supplementation (e.g. 20 g/day for 5-7 days) has typically been reported to increase total creatine content by 10-30% and phosphocreatine stores by 10-40%. Of the approximately 300 studies that have evaluated the potential ergogenic value of creatine supplementation, about 70% of these studies report statistically significant results while remaining studies generally report non-significant gains in performance. No study reports a statistically significant ergolytic effect. For example, short-term creatine supplementation has been reported to improve maximal power/strength (5-15%), work performed during sets of maximal effort muscle contractions (5-15%), single-effort sprint performance (1-5%), and work performed during repetitive sprint performance (5-15%). Moreover, creatine supplementation during training has been reported to promote significantly greater gains in strength, fat free mass, and performance primarily of high intensity exercise tasks. Although not all studies report significant results, the preponderance of scientific evidence indicates that creatine supplementation appears to be a generally effective nutritional ergogenic aid for a variety of exercise tasks in a number of athletic and clinical populations.
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The purpose of this study was to quantitatively combine and examine the results of studies examining the effectiveness of periodized (PER) compared to nonperiodized (Non-PER) training programs for strength and/or power development. Two analyses were conducted to (a) examine the magnitude of treatment effect elicited by PER strength training programs compared to Non-PER programs and (b) compare these effects after controlling for training volume, frequency, and intensity. Studies meeting the inclusion criteria were coded based on characteristics that might moderate the overall effects (i.e., participant characteristics and characteristics related to the training program). Effect sizes (ESs) were calculated for each study, and an overall ES of 0.84 (+/- 1.41) favoring PER training was found. Further analyses identified the treatment effect specific to training variation to be ES = 0.25. Significant moderating variables included age, training status, and length of training program. As a result of this statistical review of the literature, it is concluded that PER training is more effective than Non-PER training for men and women, individuals of varying training backgrounds, and for all age groups. In line with the overload principle, additions to volume, intensity, and frequency result in additional training adaptations.
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The main objective of this research was the evaluation of anaerobic power indices after long term (30days) supplementation with Cr, HMB and a combination of Cr and HMB in basketball players. Fifty two well trained basketball players took part in the experiment, with two resigning do to injury. The players were randomly assigned to four groups. The control group included 13 basketball players which were given a placebo consisting of 750ml of CHO per day. The second group of 12 athletes received creatine monohydrate with CHO over the 30 day period. The third group was supplemented with HMB, while the fourth group was given both supplements simultaneously. The supplements were ingested with a CHO solution to increase creatine uptakeAll of the basketball players performed a triple Wingate test before and immediately after the 30 day supplementation and training protocol. At rest and during the 4th minute of recovery, blood samples were drawn from the fingertip, for the evaluation of lactate concentration and acid-base equilibrium. Additional blood samples were taken from the antecubital vein, at rest and 60 minutes after the cessation of exercise in order to evaluate CK and LDH activity. Long term supplementation with creatine monohydrate seems to have a buffering effect, since greater values of Pmax and Wt are not accompanied by significantly higher post exercise LA concentration or lower pH values. This suggests a decreased rate of glycolysis do to an increase in ATP resynthesis from PCr.
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Aim of research was to examine the effects of consuming CR to muscle strength and body composition. Duration of experimental treatment was 8 weeks. Sample consisted of 14 participants aged 24±6months divided into two sub-samples: 6 participants who consumed CR and 7 participants who were placebo group. Strength was assessed using 3 tests: Bench Press 1RM, Leg Press 1RM, and Barbell Biceps Scott-maximum number of repetitions with 15kg load. Following parameters were obtained for the purpose of assessment of body composition: Body mass, Muscle mass, Body Fat, Body Water. Assessment of body composition was performed using bioelectric impedance TANITA BC-545n. Differences between the groups were assessed by ANOVA test of repeated measures. Upon taking insight into the results we may conclude that CR influences changes in body composition: Body mass (.000), Muscle mass (.039), Body Water (.010); effects to Body Fat are not statistically significant. In placebo group changes were noticed only in variable Body Water (.007). Effects to body strength were confirmed in all three variables: Bench Press (.050), Leg Press (.041), Barbell Biceps Scott (.003)., whereas no significant changes were observed in placebo group. CR is efficient dietary supplement for both professional and amateur athletes. Citation. Bojan Bjelica , Borislav Cicović, Dalibor Stević, Rosario D'Onofrio , Tijana Perović , Radomir Pržulj , Nebojša Mitrović ; Effects of creatine monohydrate (CR) to muscle strength and body composition ; Ita.
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INTRODUCTION Very few nutritional supplements have scientifically demonstrated their effectiveness as an ergogenic aid. This review will examine creatine monohydrate (MC), the β-hydroxy-β-methylbutyrate (HMB), sodium bicarbonate (BS), the β-alanine and caffeine. OBJECTIVES To analyze the effi cacy, mechanisms of action, dose, side effects and some sports that can benefit from their consumption. METHODS Searching in PubMed bibliographic database reviews from the last 15 years and original articles from the last 5 years of the studied substances. RESULTS Doses of 20 mg/day for 4-7 days are effective in improving strength and muscular power and performance in short and repeated sprints. HMB at doses of 3 g/day for at least 2 weeks contributes to increased lean mass and fat-free mass. The intake of 0.3 g/kg of BS improves performance on tests of 400-1,500 meters in athletics and intermittent sprints. Meanwhile, doses of 80 mg/kg/day of β-alanine for 4-10 weeks may improve performance in high-intensity intermittent exercise. Finally, caffeine at doses of 2 mg/kg improves responsiveness and 3-6 mg/kg improves performance in endurance tests. CONCLUSIONS The revised supplements have shown their efficacy in physical performance, but it is needed to keep in mind that most studies have been conducted with recreational-level athletes. Generally, the better the individual´s fitness level is the less improvement in physical performance the supplement shows. However, an increase of only 1% may sometimes allow the athlete to advance several positions in a final. Finally, we should draw attention to the importance of optimizing nutrition before considering the introduction of sports supplements, especially in children and youth. All analyzed substances have scientific basis supporting its ergogenic effect. All of them can be found in the market with Certificate of Quality and Purit.
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Introduction: Very few nutritional supplements have scientifically demonstrated their effectiveness as an ergogenic aid. This review will examine creatine monohydrate (MC), the β-hydroxy-β-methylbutyrate (HMB), sodium bicarbonate (BS), the β-alanine and caffeine. Objectives: To analyze the efficacy, mechanisms of action, dose, side effects and some sports that can benefit from their consumption. Methods: Searching in PubMed bibliographic database reviews from the last 15 years and original articles from the last 5 years of the studied substances. Results: Doses of 20 mg/day for 4-7 days are effective in improving strength and muscular power and performance in short and repeated sprints. HMB at doses of 3 g/day for at least 2 weeks contributes to increased lean mass and fat-free mass. The intake of 0.3 g/kg of BS improves performance on tests of 400-1,500 meters in athletics and intermittent sprints. Meanwhile, doses of 80 mg/kg/day of β-alanine for 4-10 weeks may improve performance in high-intensity intermittent exercise. Finally, caffeine at doses of 2 mg/kg improves responsiveness and 3-6 mg/kg improves performance in endurance tests. Conclusions: The revised supplements have shown their efficacy in physical performance, but it is needed to keep in mind that most studies have been conducted with recreational-level athletes. Generally, the better the individual's fitness level is the less improvement in physical performance the supplement shows. However, an increase of only 1% may sometimes allow the athlete to advance several positions in a final. Finally, we should draw attention to the importance of optimizing nutrition before considering the introduction of sports supplements, especially in children and youth. All analyzed substances have scientific basis supporting its ergogenic effect. All of them can be found in the market with Certificate of Quality and Purity.
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Creatine remains one of the most extensively studied nutritional ergogenic aids available for athletes. Hundreds of studies have reported that increasing muscle creatine stores through creatine supplementation can augment muscle creatine content, improve exercise and training adaptations, and/or provide some therapeutic benefit to some clinical populations. Consequently, creatine represents one of the most effective and popular nutritional ergogenic aids available for athletes. The future of creatine research is very promising. Researchers are attempting to determine ways to maximize creatine storage in the muscle, which types of exercise may obtain the greatest benefit from creatine supplementation, the potential medical uses of creatine, and the long-term safety and efficacy of creatine supplementation. Among these, the most promising area of research is determining the potential medical uses of creatine, particularly in patients with creatine synthesis deficiencies and neuromuscular diseases. Nevertheless, in regard to athletes, creatine has continually proved itself to be one of the most effective and safe nutritional supplements to increase strength, muscle mass, and performance. This is despite oftentimes inaccurate and misleading information that has been written about creatine in the popular media over the last several years.
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This article reviews current, as well as past, research on the topic of creatine supplementation. It is aimed toward industry professionals as a tool to update and increase their current knowledge on this topic.
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Creatine is a nutritional supplement widely used in sport, physical fitness training and bodybuilding. It is claimed to enhance performance. We describe a case in which serum creatinine is elevated due to the use of creatine ethyl esther. One week after withdrawal, the plasma creatinine had normalised. There are two types of creatine products available: creatine ethyl esther (CEE) and creatine monohydrate (CM). Plasma creatinine is not elevated in all creatine-using subjects. CEE , but not CM, is converted into creatinine in the gastrointestinal tract. As a result the use of CEE may be associated with elevated plasma creatinine levels. Since plasma creatinine is a widely used marker for renal function, the use of CEE may lead to a false assumption of renal failure.
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Aim of research was to examine the effects of consuming CR to muscle strength and body composition. Duration of experimental treatment was 8 weeks. Sample consisted of 14 participants aged 24±6months divided into two sub-samples: 6 participants who consumed CR and 7 participants who were placebo group. Strength was assessed using 3 tests: Bench Press 1RM, Leg Press 1RM, and Barbell Biceps Scott-maximum number of repetitions with 15kg load. Following parameters were obtained for the purpose of assessment of body composition: Body mass, Muscle mass, Body Fat, Body Water. Assessment of body composition was performed using bioelectric impedance TANITA BC-545n. Differences between the groups were assessed by ANOVA test of repeated measures. Upon taking insight into the results we may conclude that CR influences changes in body composition: Body mass (.000), Muscle mass (.039), Body Water (.010); effects to Body Fat are not statistically significant. In placebo group changes were noticed only in variable Body Water (.007). Effects to body strength were confirmed in all three variables: Bench Press (.050), Leg Press (.041), Barbell Biceps Scott (.003)., whereas no significant changes were observed in placebo group. CR is efficient dietary supplement for both professional and amateur athletes. Citation. Bojan Bjelica , Borislav Cicović, Dalibor Stević, Rosario D'Onofrio , Tijana Perović , Radomir Pržulj , Nebojša Mitrović ; Effects of creatine monohydrate (CR) to muscle strength and body composition ;
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Creatine monohydrate has become the supplement of choice for many athletes striving to improve sports performance. Recent data indicate that athletes may not be using creatine as a sports performance booster per se but instead use creatine chronically as a training aid to augment intense resistance training workouts. Although several studies have evaluated the combined effects of creatine supplementation and resistance training on muscle strength and weightlifting performance, these data have not been analyzed collectively. The purpose of this review is to evaluate the effects of creatine supplementation on muscle strength and weightlifting performance when ingested concomitant with resistance training. The effects of gender, interindividual variability, training status, and possible mechanisms of action are discussed. Of the 22 studies reviewed, the average increase in muscle strength (1, 3, or 10 repetition maximum [RM]) following creatine supplementation plus resistance training was 8% greater than the average increase in muscle strength following placebo ingestion during resistance training (20 vs. 12%). Similarly, the average increase in weightlifting performance (maximal repetitions at a given percent of maximal strength) following creatine supplementation plus resistance training was 14% greater than the average increase in weightlifting performance following placebo ingestion during resistance training (26 vs. 12%). The increase in bench press 1RM ranged from 3 to 45%, and the improvement in weightlifting performance in the bench press ranged from 16 to 43%. Thus there is substantial evidence to indicate that creatine supplementation during resistance training is more effective at increasing muscle strength and weightlifting performance than resistance training alone, although the response is highly variable.
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Seven male subjects performed repeated bouts of high-intensity exercise, on a cycle ergometer, before and after 6 d of creatine supplementation (20 g Cr H2O day-1). The exercise protocol consisted of five 6-s exercise periods performed at a fixed exercise intensity, interspersed with 30-s recovery periods (Part I), followed (40 s later) by one 10 s exercise period (Part II) where the ability to maintain power output was evaluated. Muscle biopsies were taken from m. vastus lateralis at rest, and immediately after (i) the fifth 6 s exercise period in Part I and (ii) the 10 s exercise period in Part II. In addition, a series of counter movement (CMJ) and squat (SJ) jumps were performed before and after the administration period. As a result of the creatine supplementation, total muscle creatine [creatine (Cr) + phosphocreatine (PCr)] concentration at rest increased from (mean +/- SEM) 128.7 (4.3) to 151.5 (5.5) mmol kg-1 dry wt (P < 0.05). This was accompanied by a 1.1 (0.5) kg increase in body mass (P < 0.05). After the fifth exercise bout in Part I of the exercise protocol, PCr concentration was higher [69.7 (2.3) vs. 45.6 (7.5) mmol kg-1 dry wt, P < 0.05], and muscle lactate was lower [26.2 (5.5) vs. 44.3 (9.9) mmol kg-1 dry wt, P < 0.05] after vs. before supplementation. In Part II, after creatinine supplementation, subjects were better able to maintain power output during the 10-s exercise period (P < 0.05). There was no change in jump performance as a result of the creatine supplementation (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)