Creatine Supplementation Reduces Muscle Inosine Monophosphate during Endurance Exercise in Humans

McConell, Glenn K.; Shinewell, Joanna; Stephens, Terry J.; Stathis, Christos G.; Canny, Benedict J.; Snow, Rodney J.

doi:10.1249/01.mss.0000179096.03129.a4

Cited by 24 publications

(15 citation statements)

References 30 publications

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“…Due to the intensity and time duration (two minutes) of the interval work periods, it was hypothesized that Cr would provide for a greater training capacity, and, therefore, the Cr group would show greater improvements in the testing measurements. McConell and colleagues [45] found that Cr improved the maintenance of energy balance in the muscle during intense aerobic exercise; however, performance was not improved, which is in agreement with the current study.…”

Section: Discussionsupporting

confidence: 92%

The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

Graef

Smith

Kendall

et al. 2009

Journal of the International Society of Sports Nutrition

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BackgroundHigh-intensity interval training has been shown to be a time-efficient way to induce physiological adaptations similar to those of traditional endurance training. Creatine supplementation may enhance high-intensity interval training, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of high-intensity interval training (HIIT) and creatine supplementation on cardiorespiratory fitness and endurance performance (maximal oxygen consumption (VO2PEAK), time-to-exhaustion (VO2PEAKTTE), ventilatory threshold (VT), and total work done (TWD)) in college-aged men.MethodsForty-three recreationally active men completed a graded exercise test to determine VO2PEAK, VO2PEAKTTE, and VT. In addition, participants completed a time to exhaustion (TTE) ride at 110% of the maximum workload reached during the graded exercise test to determine TWD (TTE (sec) × W = J). Following testing, participants were randomly assigned to one of three groups: creatine (creatine citrate) (Cr; n = 16), placebo (PL; n = 17), or control (n = 10) groups. The Cr and PL groups completed four weeks of HIIT prior to post-testing.ResultsSignificant improvements in VO2PEAK and VO2PEAKTTE occurred in both training groups. Only the Cr group significantly improved VT (16% vs. 10% improvement in PL). No changes occurred in TWD in any group.ConclusionIn conclusion, HIIT is an effective and time-efficient way to improve maximal endurance performance. The addition of Cr improved VT, but did not increase TWD. Therefore, 10 g of Cr per day for five days per week for four weeks does not seem to further augment maximal oxygen consumption, greater than HIIT alone; however, Cr supplementation may improve submaximal exercise performance.

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Section: Discussionsupporting

confidence: 92%

The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

Graef

Smith

Kendall

et al. 2009

Journal of the International Society of Sports Nutrition

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“…Creatine is the biochemical precursor of high energetic phosphocreatine and its higher storage may be associated with the applied diet. On the other hand, its higher level at the supplementation was found to be in negative correlation with IMP (known as the indicator of hypoxemia condition) during endurance exercise in humans [39, 40]. An increased level of methylhistidine in tissues may be a sign of muscle protein breakdown [41], while increased levels of tissue methionine may be a defense response against cell fat deposition [42].…”

Section: Discussionmentioning

confidence: 99%

The influence of different diets on metabolism and atherosclerosis processes—A porcine model: Blood serum, urine and tissues 1H NMR metabolomics targeted analysis

et al. 2017

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The global epidemic of cardiovascular diseases leads to increased morbidity and mortality caused mainly by myocardial infarction and stroke. Atherosclerosis is the major pathological process behind this epidemic. We designed a novel model of atherosclerosis in swine. Briefly, the first group (11 pigs) received normal pig feed (balanced diet group—BDG) for 12 months, the second group (9 pigs) was fed a Western high-calorie diet (unbalanced diet group—UDG) for 12 months, the third group (8 pigs) received a Western type high-calorie diet for 9 months later replaced by a normal diet for 3 months (regression group—RG). Clinical measurements included zoometric data, arterial blood pressure, heart rate and ultrasonographic evaluation of femoral arteries. Then, the animals were sacrificed and the blood serum, urine and skeletal muscle tissue were collected and 1H NMR based metabolomics studies with the application of fingerprinting PLS-DA and univariate analysis were done. Our results have shown that the molecular disturbances might overlap with other diseases such as onset of diabetes, sleep apnea and other obesity accompanied diseases. Moreover, we revealed that once initiated, molecular changes did not return to homeostatic equilibrium, at least for the duration of this experiment.

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“…Thus TCr (mM) and mitochondrial protein (mg) were added to the respiration chamber at ratios below and above the ratios of capacitance to resistance in intact muscle. Specifically, mixed human skeletal muscle contains ϳ30 mol TCr/g muscle (41,58) and 10 mg mitochondrial protein per gram wet muscle (49), giving a ratio of ϳ3.0 (mol TCr/mg mitochondrial protein). Because we routinely incubate ϳ0.1 mg mitochondrial protein in our assays, a range of TCr above and below 0.3 mol was employed.…”

Section: Discussionmentioning

confidence: 99%

Linear relation between time constant of oxygen uptake kinetics, total creatine, and mitochondrial content in vitro

Barstow

Willis²

2008

American Journal of Physiology-Cell Physiology

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Following the onset of moderate aerobic exercise, the rate of oxygen consumption (J(o)) rises monoexponentially toward the new steady state with a time constant (tau) in the vicinity of 30 s. The mechanisms underlying this delay have been studied over several decades. Meyer's electrical analog model proposed the concept that the tau is given by tau = R(m) x C, where R(m) is mitochondrial resistance to energy transfer, and C is metabolic capacitance, determined primarily by the cellular total creatine pool (TCr = phosphocreatine + creatine). The purpose of this study was to evaluate in vitro the J(o) kinetics of isolated rat skeletal muscle mitochondria at various levels of TCr and mitochondrial protein. Mitochondria were incubated in a medium containing 5.0 mM ATP, TCr pools of 0-1.5 mM, excess creatine kinase, and an ATP-splitting system of glucose + hexokinase (HK). Pyruvate and malate (1 mM each) were present as oxidative substrates. J(o) was measured across time after HK was added to elicit one of two levels of J(o) (40 and 60% of state 3). At TCr levels (in mM) of 0.1, 0.2, 0.3, 0.75, and 1.5, the corresponding tau values (s, means +/- SE) were 22.2 +/- 3.0, 36.3 +/- 2.2, 65.7 +/- 4.3, 168.1 +/- 22.2, and 287.3 +/- 25.9. Thus tau increased linearly with TCr (R(2) = 0.916). Furthermore, the experimentally observed tau varied linearly and inversely with the mitochondrial protein added. These in vitro results consistently conform to the predictions of Meyer's electrical analog model.

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Creatine Supplementation Reduces Muscle Inosine Monophosphate during Endurance Exercise in Humans

Abstract: Raising muscle total Cr content before exercise appears to improve the ability of the muscle to maintain energy balance during intense aerobic exercise, but not during more moderate exercise intensities.

Cited by 24 publications

References 30 publications

The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

The influence of different diets on metabolism and atherosclerosis processes—A porcine model: Blood serum, urine and tissues 1H NMR metabolomics targeted analysis

Linear relation between time constant of oxygen uptake kinetics, total creatine, and mitochondrial content in vitro

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