Thesis (Ph. D.) in Biochemistry and Molecular Biology--University of Maine, 2001. / Includes vita. Includes bibliographical references (leaves 91-103).

Thesis (M.S.)--Georgia Southern University, 2007. / "A dissertation submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Doctor of Education." Under the direction of Jim L. McMillan. ETD. Electronic version approved: May 2007. Includes bibliographical references (p. 62-82) and appendices.

Thesis (M.Ed.)--Cleveland State University, 2008. / Abstract. Title from PDF t.p. (viewed on July 8, 2008). Includes bibliographical references (p. 43-50). Available online via the OhioLINK ETD Center. Also available in print.

Proefschrift--Utrecht. / "Stellingen": [2] p. at end. Includes bibliographical references.

Thesis (Ph. D.)--Cornell University, 1922. / Caption title: Studies in creatine and creatinine metabolism. IV ... By Jeanette Allen Behre and Stanley R. Benedict. "Reprinted from Journal of biological chemistry, vol. LII, no. I, May 1922." Bibliography: p. 33.

Thesis (Ph.D.)--Ohio University, June, 2005. / Includes bibliographical references (leaves 129-150)

Creatine (Cr) is a nitrogen-containing compound endogenously synthesised in the kidneys, liver and pancreas from the amino acid arginine, with further additions from glycine and methionine. Optimal levels of muscle Cr and PCr may delay the onset of fatigue during muscle contraction that relies on the ATP-PCr energy system. Cr supplementation is considered necessary to increase skeletal muscle’s capacity to generate energy quickly, thereby enhancing maximal exercise performance. Researchers have paid little attention to the effect of Cr supplementation on aerobic endurance performance. Cr supplementation is also associated with an enhanced cellular anabolic state that may potentially prevent or lessen muscle atrophy associated with high-mileage training in ultradistance runners. The aim of this research was to investigate the ergogenic effects and safety of Cr supplementation over the short-, moderate-, and long term. For this purpose two population groups of interest were identified, namely well-trained male ultradistance runners and highly active male university students. Seventeen well-trained male ultradistance runners were paired and then, in a double-blind fashion, assigned to either a group consuming Cr monohydrate (CRE group; 38 ± 7.8 yrs; n = 9) or a group consuming placebo (PLA group; 37 ± 8.2 yrs; n = 8). Participants ingested 6 g/day supplement for six days. After post-test 1 (on day 7), the maintenance dosage was ingested at 3 g/day for 9 weeks. Participants adhered to an individually-tailored, high-intensity, high-volume sport-specific training programme. / Thesis (DPhil)--University of Pretoria, 2013. / gm2013 / Biokinetics, Sport and Leisure Sciences / unrestricted

The purpose of this investigation was to determine the effects of five weeks of creatine monohydrate ingestion on body composition, blood metabolite, and muscular performance measures in 16 female NCAA Division1 lacrosse players. Subjects were randomly divided into placebo (P,n=9) and creatine supplement (C,n=7) groups. The supplement group was administered 20g/d of creatine monohydrate in capsule form for 7 d and 2g/d thereafter for five weeks during which time the subjects were engaged in a pre-season conditioning program. Pre-and post-testing consisted of a three-site skinfold analysis, bioelectric impedence (BIA) measurements, hydrostatic weighing, isokinetic knee extension muscle endurance test (5 sets of 30 repetitions at 180 degrees/sec.), blood lactate response to the performance test (pre-test and 3 minutes post-test), a 1RM bench press and 1RM leg extension test. Pre-,mid-, and post- values of blood parameters (BUN and GPT) were measured in order to ensure the safety of the subjects. Data was analyzed using two-way ANOVA with repeated measures, and values are presented as mean±SEM for C and P groups, respectively. Testing revealed that 1RM bench press significantly increased in both groups (mean increase both groups: 4.5kg), and the C group improved significantly more than the P group (6.17±1.96 and 2.84±1.84 kg ). Percent body fat by skinfold also decreased significantly in both groups over time (0.52%), and the C group decreased their body fat significantly more than the P group (1.2+0.92 and +0.29+0.81%). Percent body water by BIA also decreased significantly in both groups over time (2.0%), and the C group decreased their percent body water significantly more than the P group (3.0±1.06 and 1.0±0.92 %). There was a trend for body fat measured by hydrostatic weighing to decrease for for both groups over the 5 weeks. Although no significant differences between groups were found in all other measures, significant time effects across groups were noted (values are absolute mean increase for both groups) for body weight (0.49±3.2kg), 1RM leg extension (1.36±4.1kg), BUN (0.07±0.03mmol/L), total work across 5 bouts of isokinetic knee extension (283.5±387.3Watts), and fat-free mass by skinfold (0.70±1.18kg). These data indicate that a regimen of dietary creatine supplementation designed to increase total muscle Cr content significantly improved the 1RM bench press strength, and decreased the percent body fat as assessed by skinfold and the percent body water as assessed by BIA of a supplemented group more than a placebo group when all female subjects are engaged in a common resistance training program. Furthermore, chronic creatine supplementation appears to have no detrimental effect on blood metabolites which indicate kidney and liver function. / Master of Science

No description available.

Background and Rationale: Creatine phosphate (PCr) is degraded 𝘷𝘪𝘢 the creatine kinase (CK) enzyme to provide energy to rephosphorylate ADP back to ATP during high-intensity muscle contractions. We, and others, have previously shown that dietary creatine (Cr) loading can improve performance in short-duration, high intensity exercise in males and females. An increase in fat-free mass has also been reported, which was higher for males compared to females. It was unknown whether dietary Cr loading increases intramuscular [Cr] equally in both genders. The purpose of this investigation was to examine the effect of oral Cr loading upon [PCr] and [Cr] and exercise performance in both males and females. Methods: Twenty-seven healthy young subjects (n = 13 male, n = 14 female) participated in the investigation. Subjects performed an ischemic handgrip test, maximum voluntary contraction of dorsiflexors and knee extensors, a 30 s maximal cycling test (Wingate), and body composition (by DEXA scanning) was determined before and after supplementation with either Cr (n = 13) (5 g by mouth 4 •d⁻¹ x 5 d, followed by 5 g•d⁻¹ x 5 d) or placebo (pl; n = 14). Muscle biopsy samples were obtained before and after supplementation and were assayed for high-energy phosphates ([Cr], [PCr] and [ATP]). Results: Cr supplementation resulted in an increase in intramuscular total creatine concentration [TCr] (pl, 129.9 ± 13.8 to 132.9 ± 10.8 mMol•kg⁻¹ dw; Cr, 129.9 ± 11.6 to 146.4 ± 20.1 mMol•kg⁻¹ dw, p < 0.05) and a difference in [PCr] (pl, 72.8 ± 15.2 to 67.3 ± 4.3 mMol•kg⁻¹ dw; Cr, 70.9 ± 7.4 to 77.1 ± 13.2 mMol•kg⁻¹ dw), but had no effect on [Cr], and no differences in gender were observed. DEXA analysis showed no significant increase in total or fat-free mass; similarly, no improvements in maximum voluntary contractions were observed in either gender. In Wingate testing, males had a significant increase in peak power (pl, 971 ± 72 W to 989 ±76 W versus Cr, 994 ± 174 W to 1042 ± 154 W) and peak power per kilogram of body weight (pl, 12.8 ± 1.3 to 12.9 ± 1.1 W•kg⁻¹; Cr, 11.5 ± 1.1 to 12.1 ± 1.3 W•kg⁻¹) as a result of creatine supplementation, while females showed no significant difference. Conclusion: Creatine monohydrate supplementation at 20 g•d⁻¹ for 5 days resulted in an increase in muscle total creatine concentration for males and females, but did not affect body composition or maximum voluntary contraction. Males showed improved performance in absolute and relative peak power generation with supplementation while females did not. This may suggest that males and females respond differently to Cr supplementation. / Thesis / Master of Science (MSc)