Absence of Effect of Potassium-Magnesium Aspartate on Physiologic Responses to Prolonged Work in Aerobically Trained Men

Rd, Hagan; Sj, Upton; Jj, Duncan; Jm, Cummings; Lr, Gettman

doi:10.1055/s-2008-1026085

Cited by 13 publications

(4 citation statements)

References 10 publications

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“…Zinc deficiency is associated with stunting in children (17) and decreased taste (18), so supplementation would not be expected to help in weight loss. Magnesium, in larger amounts than contained in the supplement and mixed with potassium, increases postprandial thermogenesis (19), but does not increase oxygen uptake with exercise (20). Thus, there is no evidence that the herbs other than C&E in the dietary herbal supplement tested significantly affected weight, appetite, or metabolic rate.…”

Section: Discussionmentioning

confidence: 99%

Effect of a Dietary Herbal Supplement Containing Caffeine and Ephedra on Weight, Metabolic Rate, and Body Composition*

et al. 2004

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GREENWAY, FRANK L., LILIAN DE JONGE, DAMIAN BLANCHARD, MADLYN FRISARD, AND STEVEN R. SMITH. Effect of a dietary herbal supplement containing caffeine and ephedra on weight, metabolic rate, and body composition. Obes Res. 2004;12:1152-1157. Objective: To evaluate the effect of a dietary supplement containing herbal caffeine (70 mg/dose) and ephedra (24 mg/dose; C&E) on metabolic rate, weight loss, body composition, and safety parameters. Research Methods and Procedures:In phase I, 12 healthy subjects with a BMI of 25 to 35 kg/m 2 had resting metabolic rate (RMR) measured for 2 hours after ingesting C&E or a placebo on two occasions 1 week apart, followed by a 1-week washout before phase II. In phase II, these 12 and 28 additional subjects were randomized to a 12-week, doubleblind trial comparing C&E (3 times/day) to placebo. In phase III, the C&E group was given open-label C&E for 3 months, and the placebo group was given C&E for 6 months. Results: In phase I, C&E gave an average 8 Ϯ 0.1% (SE) rise in RMR over 2 hours compared with placebo (p Ͻ 0.01). In phase II, weight loss at 12 weeks was 3.5 Ϯ 0.6 kg with C&E compared with 0.8 Ϯ 0.5 kg with placebo (p Ͻ 0.02). The percentage fat lost, shown by DXA, was 7.9 Ϯ 2.9% with C&E and 1.9 Ϯ 1.1% with placebo (p Ͻ 0.05). Pulse decreased more in the placebo group that in the C&E group (p Ͻ 0.03). There were no differences in lipid levels or blood pressure. In phase III, there was a 6-month loss of 7.3% and 7.8% of initial body weight for the groups on placebo and C&E during phase II, respectively. There were no serious adverse events. Discussion: C&E increased RMR significantly by 8% compared with placebo, promoted more weight and fat loss than placebo, and was well tolerated.

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Section: Discussionmentioning

confidence: 99%

Effect of a Dietary Herbal Supplement Containing Caffeine and Ephedra on Weight, Metabolic Rate, and Body Composition*

et al. 2004

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“…Those are mainly increased concentrations of its metabolites, imbalance in amino acid concentrations, and impaired transport of other amino acids through cell membranes due to the competition for a carrier. Hence, although L-Asp administration did not result in any adverse effects in human studies examining its ergogenic effects [ 176 , 177 , 178 , 179 ], animal experiments evaluating the effects of exogenous aspartate on the metabolism and resorption of amino acids, especially glutamic acid, and intestinal function and nitrogen balance are necessary. Research is also required to examine how increased intake of aspartame and other artificial sweeteners in pregnancy affects maternal and child health and its potential influence on carcinogenesis.…”

Section: Aspartate As a Dietary Supplementmentioning

confidence: 99%

Aspartic Acid in Health and Disease

Holeček

2023

Nutrients

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Aspartic acid exists in L- and D-isoforms (L-Asp and D-Asp). Most L-Asp is synthesized by mitochondrial aspartate aminotransferase from oxaloacetate and glutamate acquired by glutamine deamidation, particularly in the liver and tumor cells, and transamination of branched-chain amino acids (BCAAs), particularly in muscles. The main source of D-Asp is the racemization of L-Asp. L-Asp transported via aspartate–glutamate carrier to the cytosol is used in protein and nucleotide synthesis, gluconeogenesis, urea, and purine-nucleotide cycles, and neurotransmission and via the malate–aspartate shuttle maintains NADH delivery to mitochondria and redox balance. L-Asp released from neurons connects with the glutamate–glutamine cycle and ensures glycolysis and ammonia detoxification in astrocytes. D-Asp has a role in brain development and hypothalamus regulation. The hereditary disorders in L-Asp metabolism include citrullinemia, asparagine synthetase deficiency, Canavan disease, and dicarboxylic aminoaciduria. L-Asp plays a role in the pathogenesis of psychiatric and neurologic disorders and alterations in BCAA levels in diabetes and hyperammonemia. Further research is needed to examine the targeting of L-Asp metabolism as a strategy to fight cancer, the use of L-Asp as a dietary supplement, and the risks of increased L-Asp consumption. The role of D-Asp in the brain warrants studies on its therapeutic potential in psychiatric and neurologic disorders.

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“…Contradictory reports appeared in the literature concerning the effect of potassium and magnesium salts of aspartic acid (K+Mg Asp) on muscle performance in animals as well as in man. Some authors did not observe such effects (3,8,13,14). However, other authors reported an increase of endurance times during long-term activity (1-3 h) after administration of K+Mg Asp in animal (20) as well as in hu.…”

Section: Introductionmentioning

confidence: 94%

Effects of Potassium + Magnesium Aspartate on Muscle Metabolism and Force Development during Short Intensive Static Exercise

Haan¹,

Doorn²,

Westra³

1985

Int J Sports Med

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Improvement of muscle performance by 20%-50% in man at a submaximal work load after administration of potassium and magnesium salts of aspartic acid (K + Mg Asp) has been reported in the literature. Administration of K + Mg Asp has been reported to affect force production and energy metabolism in short-term activities of electrical stimulated animal muscles. The present study examined the possible effects of K + Mg Asp on: energy metabolism and force production of electrically stimulated rat quadriceps muscle and endurance time of a submaximal static force of voluntary contracting human muscles. In rat muscles metabolic parameters such as ATP, phosphocreatine, lactate, and L-aspartate were not influenced by oral administration of K + Mg Asp. Force parameters of rat quadriceps muscles were not enhanced after administration of K + Mg Asp. In human volunteers neither the exerted force nor the endurance time increased after oral administration of K + Mg Asp. An effect of K + Mg Asp on muscle metabolism by stimulation of the purine nucleotide cycle was not found. Improvement of muscle performance by 20%-50%, as reported for long-term activity, was not observed for short-term intensive activity.

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Absence of Effect of Potassium-Magnesium Aspartate on Physiologic Responses to Prolonged Work in Aerobically Trained Men

Cited by 13 publications

References 10 publications

Effect of a Dietary Herbal Supplement Containing Caffeine and Ephedra on Weight, Metabolic Rate, and Body Composition*

Effect of a Dietary Herbal Supplement Containing Caffeine and Ephedra on Weight, Metabolic Rate, and Body Composition*

Aspartic Acid in Health and Disease

Effects of Potassium + Magnesium Aspartate on Muscle Metabolism and Force Development during Short Intensive Static Exercise

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