The effects of creatine and glycerol hyperhydration on running economy in well trained endurance runners

Background

No published data is currently available that describes the dietary patterns or physiological profiles of athletes participating on the Kuwaiti national fencing team and its potential impact on health and physical performance. The purpose of this investigation was to: 1) collect baseline data on nutrient intake 2) collect, analyze and report baseline for body composition, plasma lipid and lipoprotein concentrations during the competitive season, 3) compare the results with the international norms, 4) and provide necessary health and nutritional information in order to enhance the athletes' performance and skills.

Methods

Fifteen national-class fencers 21.5 ± 2.6 years of age participated in this study. Food intake was measured using a 3-day food record. Body composition was estimated using both the BOD POD and Body Mass Index (BMI). Total blood lipid profiles and maximum oxygen consumption was measured for each of the subjects during the competitive season.

Results

The results of the present study showed significant differences in dietary consumption in comparison with the recommended dietary allowances (RDA). The blood lipids profile and body composition (BMI and % body fat) were in normal range in comparison with international norms However, the average VO_{2 max} value was less than the value of the other fencers.

Conclusion

Due to the results of the research study, a dietary regimen can be designed that would better enhance athletic performance and minimize any health risks associated with nutrition. Percent body fat and BMI will also be categorized for all players. In addition, the plasma blood tests will help to determine if any of the players have an excessive level of lipids or any blood abnormalities. The outcomes of present study will have a direct impact on the players health and therefore their skills and athletic performance.     

Gamma linolenic acid attenuates cardiovascular responses to stress in borderline hypertensive rats

The purpose of the present study was to investigate the effects of gamma linolenic acid (GLA) on cardiovascular responses to psychosocial stress (isolation) and to pressor hormones in the genetically borderline hypertensive rat (SHR×WKY). Adult male SHR×WKY were divided into two groups following five weeks of group housing. One group (GLA) received eight weeks constant flow osmotic pumps releasing 0.04 mg GLA in olive oil/kg-hr, while the second group received dummy pumps (DUM). One week following pump implantation, each group was divided into two subgroups and exposed to a four-week experimental period of either continued group housing (no stress) or isolation (stress). A two-week recovery period of group housing followed the experimental period. Blood pressure and heart rate were determined weekly by the tail cuff technique. At the end of the recovery period, animals in the no stress condition were anesthetized and received an arterial cannula for NOR and ANG infusion and direct BP recording. Then the responses to an ED₅₀ of NOR and ANG were determined. All animals were then killed for determination of heart weight and adrenal weight. All groups had mean control period systolic BP values ranging from 143–146 mm Hg. In the no stress condition, neither GLA nor DUM altered BP over the course of the study. However, BP increased in the DUM group durign all four weeks of the isolation period vs the control period (p<0.01), whereas BP increased only in week 1 in the GLA group (p<0.05). Heart rate increased during stress in the DUM group (p<0.05), but not in the GLA group. Vascular reactivity to NOR was unaffected by GLA administration. In contrast, GLA increased the duration of the pressor response to ANG (p<0.01), but tended to decrease the magnitude of the pressor response (p<0.09) vs DUM. GLA had no effect on heart weight/body weight ratio. Adrenal weight/body weight ratio was lower in the DUM/no stress group than all other treatment groups. These data indicate that GLA administration attenuates the cardiovascular responses to chronic stress in animals with a genetic predisposition to hypertension, in the absence of an effect on resting BP. They also demonstrate a limitation of GLA effect, in mature animals, to epigenetic pressor factors. Furthermore, GLA action may involve an alteration of the cardiovascular responses to ANG, but not NOR. These findings suggest that GLA may be useful in preventing the neurogenic triggering of hypertension by chronic stress in genetically stress-sensitive animals.     

Effects of essential fatty acid administration on cardiovascular responses to stress in the rat

This study examined the effects of 18∶2(n−6), 18∶3(n−6), 20∶4(n−6) and 18∶3(n−3) on cardiovascular responses to isolation stress in male rats. Group-acclimated rats were fasted for 2 days, then placed on a fat-free diet. Two wk later animals were divided into six groups (six animals per group) and given eight-wk intraperitoneal osmotic pumps releasing 1.47×10⁻⁷ mol/hr of either olive oil (OL), or of 18∶2(n−6), 18∶3(n−6), 20∶4(n−6) or 18∶3(n−3) in OL. Another group received dummy pumps. Two wk after pump implantation, animals were isolated for four wk. Blood pressure (BP), heart rate and body weight were followed before and during stress. Following the stress period, animals were assessed for cardiovascular reactivity to norepinephrine (NOR) and angiotensin (ANG). Prior to isolation, 18∶3(n−6) lowered BP vs OL (p<0.01). Stress increased BP within 24 hr in all groups except 18∶3(n−6) and 20∶4(n−6). Treatment with 20∶4(n−6) vs OL prevented the BP rise (p<0.001) only for the first two wk of stress. Administration of 18∶3(n−6) vs OL prevented any BP increase over the four-wk stress period (p<0.001). Stress increased heart rate in all groups except 20∶4(n−6). Heart rate was lowered by 18∶3(n−6) vs OL (p<0.01) before and during stress. Vascular reactivity to NOR was unaffected by treatment, but OL and 18∶3(n−6) decreased responses to ANG infusion. These data suggest that 18∶3(n−6) supplementation attenuates cardiovascular responses to chronic stress, and that Δ6- and Δ5-desaturase activity are inhibited during chronic psychological stress.     

Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained men

Background

Dietary supplements containing L-arginine are marketed to improve exercise performance, but the efficacy of such supplements is not clear. Therefore, this study examined the efficacy of acute ingestion of L-arginine alpha-ketoglutarate (AAKG) muscular strength and endurance in resistance trained and untrained men.

Methods

Eight resistance trained and eight untrained healthy males ingested either 3000mg of AAKG or a placebo 45 minutes prior to a resistance exercise protocol in a randomized, double-blind crossover design. One-repetition maximum (1RM) on the standard barbell bench press and leg press were obtained. Upon determination of 1RM, subjects completed repetitions to failure at 60% 1RM on both the standard barbell bench press and leg press. Heart rate was measured pre and post exercise. One week later, subjects ingested the other supplement and performed the identical resistance exercise protocol.

Results

Our data showed statistical significant differences (p<0.05) between resistance trained and untrained males for both 1RM and total load volume (TLV; multiply 60% of 1RM times the number of repetitions to failure) for the upper body. However, 1RM and TLV were not statistically different (p>0.05) between supplementation conditions for either resistance trained or untrained men in the bench press or leg press exercises. Heart rate was similar at the end of the upper and lower body bouts of resistance exercise with AAKG vs. placebo.

Conclusion

The results from our study indicate that acute AAKG supplementation provides no ergogenic benefit on 1RM or TLV as measured by the standard barbell bench press and leg press, regardless of the subjects training status.     

Free‐radical polymerization of urea,acrylic acid,and glycerol in aqueous solutions

The main objective of the present study is to produce copolymers of urea, acrylic acid, and glycerol through aqueous solution free‐radical polymerizations and analyze the structural, thermal, rheological, and release properties of the obtained materials. To do this, aqueous solution copolymerizations were performed in different reaction conditions and the obtained copolymers were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, rheological analyses, thermogravimetry, gel permeation chromatography, and rates of urea release in distilled water. The obtained results indicate that all constituents of the reacting mixture (potassium persulfate, glycerol, urea, and acrylic acid) affect the characteristics of the produced copolymers. In particular, it is shown that urea can be incorporated into the final copolymer through the proposed reaction scheme, that glycerol promotes crosslinking of polymer chains and that the obtained copolymer materials can be used in agricultural applications. POLYM. ENG. SCI., 55:1219–1229, 2015. © 2015 Society of Plastics Engineers     

Mutation of cis-proline 207 in mitochondrial creatine kinase to alanine leads to increased acid stability

We show that the mutation of an uncharged residue far from the active siteto another uncharged residue can have effects on the active site withoutdisturbing the overall structure of the protein. Cis-proline 207 ofmitochondrial creatine kinase was mutated to alanine. The mutant showed adecrease in the pH-optimum for ATP synthesis by 1.5 units while the maximumrelative activity was lowered to 53% of the wild-type enzyme. In thedirection of ATP consumption, the pH optimum was lowered by 1.3 units andthe maximum relative activity was 49% of the wild-type enzyme. The enzymekinetic parameters Km and Kd for the substrates did not changedramatically, indicating a largely unperturbed active site. Small-angleX-ray scattering was used to investigate the structural change concomitantwith the mutation, yielding a scattering profile only slightly differentfrom that of the wild-type enzyme. Neither the radius of gyration nor themolecular mass showed any significant differences, leading to theconclusion that quarternary organization and fold of the mutant and thewild-type enzymes were similar. Theoretical analysis suggests the mostprobable primary source of structural change to be a transition of residue207 peptide bond torsional angle co from the cis to the transconfiguration.     

Conjugated linoleic acid supplementation in humans: effects on fatty acid and glycerol kinetics

Recent studies with mouse adipocytes have shown that dietary conjugated linoleic acid (CLA) may reduce body fat by increasing lipolysis. The present study examined the effect of CLA supplementation on fatty acid and glycerol kinetics in six healthy, adult women who were participating in a controlled metabolic ward study. These women were fed six CLA capsules per day (3.9 g/d) for 64 d following a baseline period of 30 d. The subjects were confined to a metabolic suite for the entire 94-d study, where diet and activity were controlled and held constant. The rate of appearance (Ra) of glycerol, which indicates lipolytic rates, was similar at baseline and after 4 wk of CLA supplementation at rest (1.87±0.21 and 2.00±0.39 μmol/kg/min, respectively) and during exercise (7.12±0.74 and 6.40±0.99 μmol/kg/min, respectively). Likewise, the Ra of free fatty acids (FFA) was not significantly different after 4 wk of dietary CLA at rest (2.72±0.06 and 2.74±0.12 μmol/kg/min, respectively) or during exercise (6.99±0.40 and 5.88±0.29 μmol/kg/min, respectively). CLA supplementation also had no effect on the percentage of FFA released from lipolysis that were re-esterified. The apparent rate of FFA re-esterification was 65.2±4.2% at rest and 32.1±3.44% during exercise. Four weeks of CLA supplementation had no significant effect on fatty acid or glycerol metabolism in healthy, weight-stable, adult women.     

Solubilities of methyl oleate,oleic acid,oleyl glycerols,and oleyl glycerol mixtures in supercritical carbon dioxide

Solubility isotherms for oleic acid and methyl oleate as well as mono-, di-, and trioleylglycerol (MO, DO, and TO) in supercritical fluid CO₂ at 50 and 60°C are reported. Partition coefficients for quaternary (MO-DO-TO-CO₂) mixtures were obtained at 60°C at pressures ranging from 172 to 309 bar. Data indicate that diolein, and especially monoolein, exhibit positive deviation from ideal behavior, possibly due to intermolecular hydrogen bonding. Supercritical fluid CO₂ appears to be a good media for removal of mono- and diacylglycerol by-products from synthetic triglyceride reaction mixtures at moderate temperatures.     

Strain isolation and optimization of process parameters for bioconversion of glycerol to lactic acid

BACKGROUND: The crude glycerol from biodiesel production represents an abundant and inexpensive source which can be used as raw material for lactic acid production. The first aim of this investigation was to select a strain suitable for producing lactic acid from glycerol with a high concentration and productivity. The second aim was to obtain the optimum fermentation conditions, as a basis for large‐scale lactate production in the future. RESULTS: Eight bacterial strains, which could aerobically convert glycerol to lactic acid, were screened from soil samples. One of the strains, AC‐521, which synthesized lactic acid with a higher concentration, was identified based on its 16S rDNA sequences and physiological characteristics. These results indicated that this strain was a member of Escherichia coli. The optimal fermentation conditions for Escherichia coli AC‐521 were 42 °C, pH 6.5, 0.85 min^?1 (K_La). CONCLUSION: Escherichia coli AC‐521 suitable for producing lactic acid from glycerol with high concentration and productivity was identified. After 88 h of fed‐batch fermentation, both the lactic acid concentration and glycerol consumption reached maximum, giving 85.8 g L^?1 of lactic acid with a productivity of 0.97 g L^?1 h^?1 and a yield of 0.9 mol mol^?1 glycerol. Copyright © 2009 Society of Chemical Industry     

No effect of creatine supplementation on oxidative stress and cardiovascular parameters in spontaneously hypertensive rats

Background

Exacerbated oxidative stress is thought to be a mediator of arterial hypertension. It has been postulated that creatine (Cr) could act as an antioxidant agent preventing increased oxidative stress. The aim of this study was to investigate the effects of nine weeks of Cr or placebo supplementation on oxidative stress and cardiovascular parameters in spontaneously hypertensive rats (SHR).

Findings

Lipid hydroperoxidation, one important oxidative stress marker, remained unchanged in the coronary artery (Cr: 12.6 ± 1.5 vs. Pl: 12.2 ± 1.7 nmol·mg^-1; p = 0.87), heart (Cr: 11.5 ± 1.8 vs. Pl: 14.6 ± 1.1 nmol·mg^-1; p = 0.15), plasma (Cr: 67.7 ± 9.1 vs. Pl: 56.0 ± 3.2 nmol·mg^-1; p = 0.19), plantaris (Cr: 10.0 ± 0.8 vs. Pl: 9.0 ± 0.8 nmol·mg^-1; p = 0.40), and EDL muscle (Cr: 14.9 ± 1.4 vs. Pl: 17.2 ± 1.5 nmol·mg^-1; p = 0.30). Additionally, Cr supplementation affected neither arterial blood pressure nor heart structure in SHR (p > 0.05).

Conclusions

Using a well-known experimental model of systemic arterial hypertension, this study did not confirm the possible therapeutic effects of Cr supplementation on oxidative stress and cardiovascular dysfunction associated with arterial hypertension.     

Copolyester of trimellitic acid,glycerol, and poly(ethylene glycol): Synthesis and characterization

A series of copolyesters having a broad range of biodegradable crosslinks were synthesised by FeCl₃‐catalyzed polyesterification of trimellitic acid and glycerol containing a small mol percent of poly(ethylene glycol) (PEG) of varied molecular weights. The polymer samples designated as I (1.5% PEG 2000), II (4.5% PEG 2000), III (7.5% PEG 2000), IV (1.5% PEG 4000), V (4.5% PEG 4000), VI (7.5% PEG 4000), VII (1.5% PEG 6000), VIII (4.5% PEG 6000), and IX (without PEG) are insoluble and moderately tough‐to‐elastic solids and were characterized by their swelling values in ethanol, glass transition temperatures (T_g), IR spectra, and X‐ray diffractograms. Sample IX (0% PEG) has the lowest equilibrium swelling (12% at 25°C) and the highest T_g (155°C) and, therefore, the highest crosslink density. The swelling increases and the T_g decreases as the PEG content or PEG molecular weight in a glycerol–PEG combination increases, indicating a corresponding decrease in the crosslink density of the polymers. Further, the equilibrium swelling value increases with increasing temperature. The IR spectra of the polymers indicate the formation of ester bonds at the expense of COOH and OH groups. The X‐ray diffractograms show their semicrystalline nature. The percent crystallinity values of 53, 52, 49, and 46 for II, III, V, and VII, respectively, and 54 for IX showed that the percent crystallinity decreases with an increasing PEG content and molecular weight in the same way as do the T_g values. Thus, higher T_g values are associated with a higher percent crystallinity, that is, with structures of higher order. The synthesized polymer samples with varied crosslink (biodegradable) densities are expected to be very suitable as matrices for controlled drug delivery over a varied period of time. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 343–346, 2004     

Synthesis of absorbent polymer films made from fatty acid methyl esters,glycerol, and glutaric acid: Thermal,mechanical, and porosity analyses

In previous studies, monoglycerides (MGs) were incorporated into the matrix of poly(glutaric acid–glycerol) films to investigate their effect on the thermal, mechanical, and solvent absorption properties of the resultant films. In this study, the same properties were monitored when fatty acid methyl esters (FAME) were added to the polymer film formulation. Thermogravimetric analysis showed that, while the decomposition profile of the FAME and MG-infused films were different, the final decomposition temperatures were similar for both film types at approximately 400 °C. Degree of branching (DB%) was calculated from nuclear magnetic resonance data and was used to examine the effect of DB% on the mechanical and absorption properties of the films. Experimental results did not show any correlation with DB% and any of the physical, chemical, mechanical, or thermal properties studied. Relative to the poly(glycerol–glutaric acid) control, the incorporation of MG into the polymer matrix resulted in improved % absorption but decreased the mechanical property values. Conversely, adding FAME into the matrix improved the mechanical property values; however, there was no significant change in the % absorption values relative to the control. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47822.     

Electrical behavior of polyurethane derived from polyols synthesized with glycerol,phthalic anhydride,and oleic acid

The direct current (DC) and alternating current (AC) conductivity of polyurethane (PUR) derived from polyols synthesized with glycerol, phthalic anhydride, and oleic acid were investigated in this article. The PUR was prepared by varying the oleic acid content in polyol (28, 40, and 65%) and the NCO/OH ratio of the PUR was varied to 1.2, 1.4, and 1.6. The electrical conduction studied by measuring the dependence of current on the applied field and temperature. Electrical conductivity in PUR was expressed by Arrhenius relations and the activation energies were calculated. Moreover, hyperbolic sine function was used to determine the conduction mechanism in PUR. It's presumed that the conduction mechanism was assisted by ions for the PUR which were contributed by oleic acid due to dissociation of protons and highly polar urethane groups in PUR. Furthermore, the dielectric behaviors of the material have been measured at room temperature in the frequency range of 100 Hz to 40 MHz. The frequency‐dependent conductivity of PUR materials has been analyzed using a Jonscher's power law expression and the plot exhibits the typical behavior of ionic materials, i.e., the DC plateau and the frequency dependent region. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Flexible,hard, and tough biobased polyurethane thermosets from renewable materials: glycerol and 10-undecenoic acid

The main theme of this work is to develop 100% biobased low viscous polyols from renewable resources. An epoxide compound (UA-GLY-E) was synthesized through esterification of glycerol and 10-undecenoic acid preceded by peroxidation. For the first time, UA-GLY-E was utilized as a building block in the generation of low viscous polyols and polyurethanes therefrom. The biobased polyols were synthesized by epoxide ring opening of UA-GLY-E with different nucleophiles, namely glycerol, water, and methanol. The advantage of these biobased polyols is their low viscosity and at the same time high functionality. These biobased polyols were further converted into poly(urethane–urea) coatings by reacting with methylene diphenyl diisocyanate. The impact of peripheral structural change in the polyols on the properties of polyols and their polyurethane coatings was studied. Flexible, hard, and tough thermosets have been prepared successfully from the same epoxy compound by altering the peripheral moiety in the polyol structure. Biobased polyurethanes prepared from glycerol and water-based polyols have shown better crosslinking density over the methanol-based polyol. Moreover, these biobased polyurethane films have shown good thermal stability, mechanical strength, and chemical resistance as well.     

Behavior of alpha,gamma, and delta tocopherols with linoleic acid in aqueous media

Tocopherols can exhibit opposite effects in aqueous media on linoleic acid autoxidation rate. The effect which was observed depended on tocopherol concentration and on the tocopherol itself. At 0.05 mole of tocopherol per mole of linoleic acid, α-tocopherol was prooxidant while in similar conditions, δ-tocopherol was anti-oxidant as well as γ-tocopherol. However, this latter one exhibited a slight antioxidant activity. When tocopherol concentration decreased (twice as weak), α-tocopherol still exhibited the same pro-oxidant activity, while the antioxidant effect of γ and δ tocopherols was increased. The study of tocopherol stability by HPLC has shown that tocopherol oxidation increased in order δ < γ < α. There was a relationship between the ability for a tocopherol to be easily oxidized by air and its prooxidant activity. Tocopherol oxidation would enhance the formation of a perhydroxyl radical ([·OOH] or one of this type [O₂0=, ·OH]) which was responsible for the prooxidant effect.     

Isothermal crystallization kinetics and mechanical properties of polycaprolactone composites with zinc oxide,oleic acid,and glycerol monooleate

The isothermal crystallization and mechanical behavior of polycaprolactone (PCL) with zinc oxide (ZnO) with oleic acid and glycerol monooleate (GMO) were studied. Theoretical melting points calculated by the Flory–Huggins and Thompson–Gibbs models were thoroughly compared with differential scanning calorimetry experimental observations. The isothermal crystallization kinetic parameters by Avrami analysis showed that crystallization was controlled by nucleation, crystal growth was spherical, and the nucleation type changed between thermal and athermal nucleation. X‐ray diffraction showed that when the additives were used together both the crystal thickness and the degree of crystallinity increased. A multiple‐response regression analysis was made with the ZnO, oleic acid, and GMO concentrations as variables and the crystallinity as output. Interaction parameters by the Pukanzky model were calculated from the tensile strength at the yield point and indicated that the addition of oleic acid or GMO improved the interface between the ZnO particles and PCL. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1259‐1275, 2013