44 research outputs found
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 (H<sub>2</sub>O<sub>2</sub>), 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<sup>-1</sup>; p = 0.004), while H<sub>2</sub>O<sub>2 </sub>demonstrated a trend for lowering (4.42 ± 0.32 vs. 3.78 ± 0.21 μmol L<sup>-1</sup>; p = 0.074). Both NOx (18.79 ± 1.92 vs. 26.97 ± 2.40 μmol L<sup>-1</sup>; p = 0.003) and TEAC (0.47 ± 0.01 vs. 0.51 ± 0.01 mmol L<sup>-1</sup>; p = 0.001) increased from pre to post fast, while ORAC was unchanged (5243 ± 103 vs. 5249 ± 183 μmol L<sup>-1 </sup>TE; 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 10<sup>3</sup>·μL<sup>-1</sup>), blood urea nitrogen (13.07 ± 0.58 vs. 10.14 ± 0.59 mg·dL<sup>-1</sup>), 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<sup>-1</sup>), total cholesterol (171.07 ± 4.57 vs. 138.69 ± 4.39 mg·dL<sup>-1</sup>), LDL-C (98.38 ± 3.89 vs. 76.07 ± 3.53 mg·dL<sup>-1</sup>), HDL-C (55.65 ± 2.50 vs. 47.58 ± 2.19 mg·dL<sup>-1</sup>), 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<sup>-1</sup>; 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<sup>-1</sup>; 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
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
Impact of oral ubiquinol on blood oxidative stress and exercise performance
Coenzyme Q10 (CoQ10) plays an important role in bioenergetic processes and has antioxidant activity. Fifteen exercise-trained individuals (10 men and 5 women; 3065 years) received reduced CoQ10 (Kaneka QH ubiquinol; 300 mg per day) or a placebo for four weeks in a random order, double blind, cross-over design (3 week washout). After each four-week period, a graded exercise treadmill test and a repeated cycle sprint test were performed (separated by 48 hours). Blood samples were collected before and immediately following both exercise tests and analyzed for lactate, malondialdehyde, and hydrogen peroxide. Resting blood samples were analyzed for CoQ10 (ubiquinone and ubiquinol) profile before and after each treatment period. Treatment with CoQ10 resulted in a significant increase in total blood CoQ10 (138; P=0.02) and reduced blood CoQ10 (168; P=0.02), but did not improve exercise performance (with the exception of selected individuals) or impact oxidative stress. The relationship between the percentage change in total blood CoQ10 and the cycle sprint total work (R2=0.6009) was noted to be moderate to strong. We conclude that treatment with CoQ10 in healthy, exercise-trained subjects increases total and reduced blood CoQ10, but this increase does not translate into improved exercise performance or decreased oxidative stress. © 2012 Richard J. Bloomer et al