Acute vs. Chronic Citrulline Malate Supplementation on Muscle Fatigue

Citrulline malate has been proposed to aid in reducing fatigue by increasing blood flow through promoting an increase in the nitric oxide synthase pathway along with the ability to remove ammonia and lactate accumulations. Results on the effectiveness of an acute supplementation are mixed, but it is proposed that regular consumption may help to attenuate the onset of fatigue during exercise. PURPOSE: To investigate the effects of acute and chronic citrulline malate supplementation on fatigue rate of the quadriceps. METHODS: Recreationally trained males (n=18, 24±5 yr, 83±14 kg, 174±6 cm) participated in seven testing sessions. The familiarization session consisted of participants performing a graded exercise test to determine max power output. In a randomized, counterbalanced order, participants consumed a placebo (PL) and citrulline malate (CM) treatment for two separate dosing periods. For each dosing period, participants reported on three separate days with seven days between each visit. The first experimental testing session for each dosing period was considered the baseline day (BL), the second session the acute day (D1), and the third session the chronic day (D2). For chronic supplementation, all participants consumed each treatment for seven consecutive days. The exercise protocol all testing sessions and the four supplemental testing sessions included exercising on a cycle ergometer at 50-60% of their max power output for 30 min. Following the bout, all participants performed the Thorstensson test on an isokinetic dynamometer for torque, power, and fatigue rate of the dominate leg quadriceps. RESULTS: The acute supplement x time interactions were not significant (p\u3e0.05) for peak power (PL BL 469+81 W, PL D1 490+97 W vs. CM BL 465+85 W, CM D1 480+103 W), peak torque (PL BL 150+26 Nm, PL D1 157+32 Nm vs. CM BL 149+26 Nm, CM D1 156+33 Nm), fatigue rate (PL BL 57+9%, PL D1 57+10% vs. CM BL 57+10%, CM D1 56+9%), and heart rate (PL BL 156+17 bpm, PL D1 146+13 bpm vs. CM BL 155+11 bpm, CM D1 146+11 bpm). The chronic supplement x time interactions were not significant (p\u3e0.05) for peak power (PL BL 469+81 W, PL D2 501+99 W vs. CM BL 464+85 W, CM D2 501+81 W), peak torque (PL BL 150+26 Nm, PL D2 161+31 Nm vs. CM BL 149+27 Nm, CM D2 161+26 Nm), fatigue rate (PL BL 57+9%, PL D2 58+9% vs. CM BL 57+10%, CM D2 58+9%), and heart rate (PL BL 156+17 bpm, PL D2 146+9 bpm vs. CM BL 155+11 bpm, CM D2 146+9 bpm). CONCLUSION: The results of this study suggest that neither acute or chronic supplementation of CM had an effect on recovery or fatigue rate of the quadriceps. Based on the data collected there were no significant differences between the recorded values for torque and power for each participant

A 21 day Daniel Fast improves selected biomarkers of antioxidant status and oxidative stress in men and women

<p>Abstract</p> <p>Background</p> <p>Dietary modification via both caloric and nutrient restriction is associated with multiple health benefits, some of which are related to an improvement in antioxidant status and a decrease in the production of reactive oxygen species. The Daniel Fast is based on the Biblical book of Daniel, is commonly partaken for 21 days, and involves food intake in accordance with a stringent vegan diet. The purpose of the present study was to determine the effect of a 21 day Daniel Fast on biomarkers of antioxidant status and oxidative stress.</p> <p>Methods</p> <p>43 subjects (13 men; 30 women; 35 ± 1 yrs; range: 20-62 yrs) completed a 21 day Daniel Fast following the guidelines provided by investigators. Subjects reported to the lab in a 12 hour post-absorptive state both pre fast (day 1) and post fast (day 22). At each visit, blood was collected for determination of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), nitrate/nitrite (NOx), Trolox Equivalent Antioxidant Capacity (TEAC), and Oxygen Radical Absorbance Capacity (ORAC). Subjects recorded dietary intake during the 7 day period immediately prior to the fast and during the final 7 days of the fast.</p> <p>Results</p> <p>A decrease was noted in MDA (0.66 ± 0.0.03 vs. 0.56 ± 0.02 μmol L^-1; p = 0.004), while H₂O₂demonstrated a trend for lowering (4.42 ± 0.32 vs. 3.78 ± 0.21 μmol L^-1; p = 0.074). Both NOx (18.79 ± 1.92 vs. 26.97 ± 2.40 μmol L^-1; p = 0.003) and TEAC (0.47 ± 0.01 vs. 0.51 ± 0.01 mmol L^-1; p = 0.001) increased from pre to post fast, while ORAC was unchanged (5243 ± 103 vs. 5249 ± 183 μmol L^-1TE; p = 0.974). As expected, multiple differences in dietary intake were noted (p < 0.05), including a reduction in total calorie intake (2185 ± 94 vs. 1722 ± 85).</p> <p>Conclusion</p> <p>Modification of dietary intake in accordance with the Daniel Fast is associated with an improvement in selected biomarkers of antioxidant status and oxidative stress, including metabolites of nitric oxide (i.e., NOx).</p

Effect of a 21 day Daniel Fast on metabolic and cardiovascular disease risk factors in men and women

<p>Abstract</p> <p>Background</p> <p>Dietary modification via caloric restriction is associated with multiple effects related to improved metabolic and cardiovascular health. However, a mandated reduction in kilocalories is not well-tolerated by many individuals, limiting the long-term application of such a plan. The Daniel Fast is a widely utilized fast based on the Biblical book of Daniel. It involves a 21 day <it>ad libitum </it>food intake period, devoid of animal products and preservatives, and inclusive of fruits, vegetables, whole grains, legumes, nuts, and seeds. The purpose of the present study was to determine the efficacy of the Daniel Fast to improve markers of metabolic and cardiovascular disease risk.</p> <p>Methods</p> <p>43 subjects (13 men; 30 women; 35 ± 1 yrs; range: 20-62 yrs) completed a 21 day period of modified food intake in accordance with detailed guidelines provided by investigators. All subjects purchased and prepared their own food. Following initial screening, subjects were given one week to prepare for the fast, after which time they reported to the lab for their pre-intervention assessment (day 1). After the 21 day fast, subjects reported to the lab for their post-intervention assessment (day 22). For both visits, subjects reported in a 12 hr fasted state, performing no strenuous physical activity during the preceding 24-48 hrs. At each visit, mental and physical health (SF-12 form), resting heart rate and blood pressure, and anthropometric variables were measured. Blood was collected for determination of complete blood count, metabolic panel, lipid panel, insulin, HOMA-IR, and C-reactive protein (CRP). Subjects' self-reported compliance, mood, and satiety in relation to the fast were also recorded. Diet records were maintained by all subjects during the 7 day period immediately prior to the fast (usual intake) and during the final 7 days of the fast.</p> <p>Results</p> <p>Subjects' compliance to the fast was 98.7 ± 0.2% (mean ± SEM). Using a 10 point scale, subjects' mood and satiety were both 7.9 ± 0.2. The following variables were significantly (p < 0.05) lower following the fast as compared to before the fast: white blood cell count (5.68 ± 0.24 vs. 4.99 ± 0.19 10³·μL^-1), blood urea nitrogen (13.07 ± 0.58 vs. 10.14 ± 0.59 mg·dL^-1), blood urea nitrogen/creatinine (14.74 ± 0.59 vs. 11.67 ± 0.68), protein (6.95 ± 0.07 vs. 6.77 ± 0.06 g·dL^-1), total cholesterol (171.07 ± 4.57 vs. 138.69 ± 4.39 mg·dL^-1), LDL-C (98.38 ± 3.89 vs. 76.07 ± 3.53 mg·dL^-1), HDL-C (55.65 ± 2.50 vs. 47.58 ± 2.19 mg·dL^-1), SBP (114.65 ± 2.34 vs. 105.93 ± 2.12 mmHg), and DBP (72.23 ± 1.59 vs. 67.00 ± 1.43 mmHg). Insulin (4.42 ± 0.52 vs. 3.37 ± 0.35 μU·mL^-1; p = 0.10), HOMA-IR (0.97 ± 0.13 vs.0.72 ± 0.08; p = 0.10), and CRP (3.15 ± 0.91 vs. 1.60 ± 0.42 mg·L^-1; p = 0.13), were lowered to a clinically meaningful, albeit statistically insignificant extent. No significant difference was noted for any anthropometric variable (p > 0.05). As expected, multiple differences in dietary intake were noted (p < 0.05), including a reduction in total kilocalorie intake (2185 ± 94 vs. 1722 ± 85).</p> <p>Conclusion</p> <p>A 21 day period of modified dietary intake in accordance with the Daniel Fast is 1) well-tolerated by men and women and 2) improves several risk factors for metabolic and cardiovascular disease. Larger scale, randomized studies, inclusive of a longer time period and possibly a slight modification in food choice in an attempt to maintain HDL cholesterol, are needed to extend these findings.</p

Molecular Pathways Underlying Adaptive Repair of the Injured Kidney: Novel Donation After Cardiac Death and Acute Kidney Injury Platforms

International audienceObjective: To test the hypothesis that gene expression profiling in peripheral blood from patients who have undergone kidney transplantation (KT) will provide mechanistic insights regarding graft repair and regeneration.Background: Renal grafts obtained from living donors (LD) typically function immediately, whereas organs from donation after cardiac death (DCD) or acute kidney injury (AKI) donors may experience delayed function with eventual recovery. Thus, recipients of LD, DCD, and AKI kidneys were studied to provide a more complete understanding of the molecular basis for renal recovery.Methods: Peripheral blood was collected from LD and DCD/AKI recipients before transplant and throughout the first 30 days thereafter. Total RNA was isolated and assayed on whole genome microarrays.Results: Comparison of longitudinal gene expression between LD and AKI/DCD revealed 2 clusters, representing 141 differentially expressed transcripts. A subset of 11 transcripts was found to be differentially expressed in AKI/DCD versus LD. In all recipients, the most robust gene expression changes were observed in the first day after transplantation. After day 1, gene expression profiles differed depending upon the source of the graft. In patients receiving LD grafts, the expression of most genes did not remain markedly elevated beyond the first day post-KT. In the AKI/DCD groups, elevations in gene expression were maintained for at least 5 days post-KT. In all recipients, the pattern of coordinate gene overexpression subsided by 28 to 30 days.Conclusions: Gene expression in peripheral blood of AKI/DCD recipients offers a novel platform to understand the potential mechanisms and timing of kidney repair and regeneration after transplantation

Effect of betaine supplementation on plasma nitrate/nitrite in exercise-trained men

Background: Betaine, beetroot juice, and supplemental nitrate have recently been reported to improve certain aspects of exercise performance, which may be mechanistically linked to increased nitric oxide. The purpose of the present study was to investigate the effect of betaine supplementation on plasma nitrate/nitrite, a surrogate marker or nitric oxide, in exercise-trained men.Methods: We used three different study designs (acute intake of betaine at 1.25 and 5.00 grams, chronic intake of betaine at 2.5 grams per day for 14 days, and chronic [6 grams of betaine per day for 7 days] followed by acute intake [6 grams]), all involving exercise-trained men, to investigate the effects of orally ingested betaine on plasma nitrate/nitrite. Blood samples were collected before and at 30, 60, 90, and 120 min after ingestion of 1.25 and 5.00 grams of betaine (Study 1); before and after 14 days of betaine supplementation at a dosage of 2.5 grams (Study 2); and before and after 7 days of betaine supplementation at a dosage of 6 grams, followed by acute ingestion of 6 grams and blood measures at 30 and 60 min post ingestion (Study 3).Results: In Study 1, nitrate/nitrite was relatively unaffected and no statistically significant interaction (p = 0.99), dosage (p = 0.69), or time (p = 0.91) effects were noted. Similar findings were noted in Study 2, with no statistically significant interaction (p = 0.57), condition (p = 0.98), or pre/post intervention (p = 0.17) effects noted for nitrate/nitrite. In Study 3, no statistically significant changes were noted in nitrate/nitrite between collection times (p = 0.97).Conclusion: Our data indicate that acute or chronic ingestion of betaine by healthy, exercise-trained men does not impact plasma nitrate/nitrite. These findings suggest that other mechanisms aside from increasing circulating nitric oxide are likely responsible for any performance enhancing effect of betaine supplementation. © 2011 Bloomer et al; licensee BioMed Central Ltd

Health Outcomes of Gastric Bypass Patients Compared to Nonsurgical, Nonintervened Severely Obese

Favorable health outcomes at 2 years postbariatric surgery have been reported. With exception of the Swedish Obesity Subjects (SOS) study, these studies have been surgical case series, comparison of surgery types, or surgery patients compared to subjects enrolled in planned nonsurgical intervention. This study measured gastric bypass effectiveness when compared to two separate severely obese groups not participating in designed weight-loss intervention. Three groups of severely obese subjects (N = 1,156, BMI ≥ 35 kg/m2) were studied: gastric bypass subjects (n = 420), subjects seeking gastric bypass but did not have surgery (n = 415), and population-based subjects not seeking surgery (n = 321). Participants were studied at baseline and 2 years. Quantitative outcome measures as well as prevalence, incidence, and resolution rates of categorical health outcome variables were determined. All quantitative variables (BMI, blood pressure, lipids, diabetes-related variables, resting metabolic rate (RMR), sleep apnea, and health-related quality of life) improved significantly in the gastric bypass group compared with each comparative group (all P < 0.0001, except for diastolic blood pressure and the short form (SF-36) health survey mental component score at P < 0.01). Diabetes, dyslipidemia, and hypertension resolved much more frequently in the gastric bypass group than in the comparative groups (all P < 0.001). In the surgical group, beneficial changes of almost all quantitative variables correlated significantly with the decrease in BMI. We conclude that Roux-en-Y gastric bypass surgery when compared to severely obese groups not enrolled in planned weight-loss intervention was highly effective for weight loss, improved health-related quality of life, and resolution of major obesity-associated complications measured at 2 years

NREM Sleep Parasomnia Associated with Chiari I Malformation

Parasomnias are common sleep disorders in children, and most cases resolve naturally by adolescence.1 They represent arousal disorders beginning in NREM sleep and are generally non-concerning in children. The diagnosis can usually be made by clinical assessment, and testing with polysomnography is not routinely indicated.2 However, in certain cases with atypical features, polysomnography and more extensive neurologic evaluation are medically indicated

Influence of acute exercise of varying intensity and duration on postprandial oxidative stress

INTRODUCTION: Aerobic exercise can reduce postprandial lipemia, and possibly oxidative stress, when performed prior to a lipid-rich meal