RESUMO
INTRODUCTION: Aerobic exercise can reduce postprandial lipemia, and possibly oxidative stress, when performed prior to a lipid-rich meal. PURPOSE: To compare the impact of acute exercise on postprandial oxidative stress. METHODS: We compared aerobic and anaerobic exercise bouts of different intensities and durations on postprandial blood triglycerides (TAG), oxidative stress biomarkers (malondialdehyde, hydrogen peroxide, advanced oxidation protein products), and antioxidant status (trolox equivalent antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase). Twelve trained men (21-35 years) underwent four conditions: (1) No exercise rest; (2) 60-min aerobic exercise at 70% heart rate reserve; (3) five 60-s sprints at 100% max capacity; and (4) ten 15-s sprints at 200% max capacity. All exercise bouts were performed on a cycle ergometer. A high-fat meal was consumed 1 h after exercise cessation. Blood samples were collected pre-meal and 2 and 4 h post-meal and analyzed for TAG, oxidative stress biomarkers, and antioxidant status. RESULTS: No significant interaction or condition effects were noted for any variable (p > 0.05), with acute exercise having little to no effect on the magnitude of postprandial oxidative stress. CONCLUSION: In a sample of healthy, well-trained men, neither aerobic nor anaerobic exercise attenuates postprandial oxidative stress in response to a high-fat meal.
Assuntos
Exercício Físico , Estresse Oxidativo , Período Pós-Prandial , Adulto , Produtos da Oxidação Avançada de Proteínas/sangue , Catalase/sangue , Gorduras na Dieta/metabolismo , Glutationa Peroxidase/sangue , Frequência Cardíaca , Humanos , Peróxido de Hidrogênio/sangue , Masculino , Malondialdeído/sangue , Superóxido Dismutase/sangue , Triglicerídeos/sangueRESUMO
Considerable interest has been shown in the ability of caloric restriction (CR) to improve multiple parameters of health and to extend lifespan. CR is the reduction of caloric intake - typically by 20 - 40% of ad libitum consumption - while maintaining adequate nutrient intake. Several alternatives to CR exist. CR combined with exercise (CE) consists of both decreased caloric intake and increased caloric expenditure. Alternate-day fasting (ADF) consists of two interchanging days; one day, subjects may consume food ad libitum (sometimes equaling twice the normal intake); on the other day, food is reduced or withheld altogether. Dietary restriction (DR) - restriction of one or more components of intake (typically macronutrients) with minimal to no reduction in total caloric intake - is another alternative to CR. Many religions incorporate one or more forms of food restriction. The following religious fasting periods are featured in this review: 1) Islamic Ramadan; 2) the three principal fasting periods of Greek Orthodox Christianity (Nativity, Lent, and the Assumption); and 3) the Biblical-based Daniel Fast. This review provides a summary of the current state of knowledge related to CR and DR. A specific section is provided that illustrates related work pertaining to religious forms of food restriction. Where available, studies involving both humans and animals are presented. The review includes suggestions for future research pertaining to the topics of discussion.
Assuntos
Restrição Calórica , Jejum/fisiologia , Longevidade , Religião , Adulto , Idoso , Envelhecimento/fisiologia , Animais , Biomarcadores/metabolismo , Fenômenos Fisiológicos Cardiovasculares , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , Cristianismo , Dieta Redutora , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Exercício Físico , Feminino , Humanos , Islamismo , Expectativa de Vida , Masculino , Metionina/administração & dosagem , Pessoa de Meia-Idade , Atividade Motora , Triptofano/administração & dosagemRESUMO
BACKGROUND: Licorice flavonoid oil (LFO) has been reported to minimize visceral adipose tissue gain in obese mice and to result in a decrease in body weight and body fat in humans; the effects of which may be more pronounced when administered in an overfed state. METHODS: We investigated the effects of LFO in two separate studies. Study 1 included a sample of overweight or grade I-II obese men and women (N = 22) who followed their usual dietary and physical activity programs. Study 2 included a sample of athletic men who followed their usual dietary and physical activity programs but consumed a daily supplemental meal (25% above daily energy requirements) in an attempt to induce a state of overfeeding. In both studies, subjects were randomly assigned (double-blind) to either LFO or a placebo for eight weeks, and anthropometric and multiple biochemical outcomes (e.g., markers of oxidative stress, markers of insulin sensitivity, blood lipids, etc.) were obtained before and following the intervention. RESULTS: No differences of statistical significance were noted between LFO and placebo for any measured variable in Study 1 or Study 2. When investigating the percent change from baseline for data in Study 2, although not of statistical significance, subjects in the LFO condition experienced less overall fat gain, as well as attenuation in the elevation in selected blood lipids (e.g., cholesterol, LDL-C, and triglycerides). CONCLUSION: These combined data indicate little effect of LFO supplementation within a sample of overweight/obese men and women or athletic men, with the possible exception of attenuation in body fat gain and selected components of the blood lipid panel in response to an overfeeding condition.
Assuntos
Suplementos Nutricionais , Flavonoides/farmacologia , Glycyrrhiza/química , Óleos de Plantas/farmacologia , Adiposidade/efeitos dos fármacos , Adulto , Animais , Antropometria , Contagem de Células Sanguíneas , Glicemia/análise , Proteínas Sanguíneas/análise , Método Duplo-Cego , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipídeos/sangue , Masculino , Camundongos , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: The use of 1,3-dimethylamylamine (geranamine), alone and in combination with caffeine, is becoming widespread within the dietary supplement industry. To our knowledge, no data are available concerning the effects of oral geranamine intake on heart rate (HR) and blood pressure in individuals. METHODS: Ten young healthy men and women ingested 1 of 5 conditions on different days using a double-blind, randomized, crossover design. The following were ingested after a 10-hour overnight fast: 250 mg caffeine (C), 50 mg geranamine (G 50 mg), 75 mg geranamine (G 75 mg), 250 mg caffeine + 50 mg geranamine (C + G 50 mg), and 250 mg caffeine + 75 mg geranamine (C + G 75 mg). Heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), and rate pressure product (RPP) were measured pre-ingestion and at 30, 60, 90, and 120 minutes post-ingestion. Plasma norepinephrine (NE) and epinephrine (EPI) were measured pre-ingestion and at 60 and 120 minutes post-ingestion. RESULTS: Heart rate was unaffected by treatment, but blood pressure and RPP were higher with geranamine, generally in a dose-dependent manner. The peak percent change from pre-ingestion in SBP (~20%), DBP (~17%), and RPP (~9%) was noted with C + G 75 mg at 60 minutes post-ingestion. Plasma NE and EPI were relatively unaffected by treatment. CONCLUSION: We report for the first time that acute ingestion of 1,3-dimethylamylamine alone and in combination with caffeine results in an increase in SBP, DBP, and RPP without an increase in HR. The largest increase is observed at 60 minutes post-ingestion of C + G 75 mg. These changes cannot be explained by circulating NE and EPI.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Cafeína/farmacologia , Geranium , Frequência Cardíaca/efeitos dos fármacos , Extratos Vegetais/farmacologia , Administração Oral , Adulto , Análise de Variância , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: The purpose of this investigation was to determine the effects of a dietary supplement (Ambrotose AO®) on resting and exercise-induced blood antioxidant capacity and oxidative stress in exercise-trained and untrained men and women. METHODS: 25 individuals (7 trained and 5 untrained men; 7 trained and 6 untrained women) received Ambrotose AO® (4 capsules per day = 2 grams per day) or a placebo for 3 weeks in a random order, double blind cross-over design (with a 3 week washout period). Blood samples were collected at rest, and at 0 and 30 minutes following a graded exercise treadmill test (GXT) performed to exhaustion, both before and after each 3 week supplementation period. Samples were analyzed for Trolox Equivalent Antioxidant Capacity (TEAC), Oxygen Radical Absorbance Capacity (ORAC), malondialdehyde (MDA), hydrogen peroxide (H2O2), and nitrate/nitrite (NOx). Quality of life was assessed using the SF-12 form and exercise time to exhaustion was recorded. Resting blood samples were analyzed for complete blood count (CBC), metabolic panel, and lipid panel before and after each 3 week supplementation period. Dietary intake during the week before each exercise test was recorded. RESULTS: No condition effects were noted for SF-12 data, for GXT time to exhaustion, or for any variable within the CBC, metabolic panel, or lipid panel (p > 0.05). Treatment with Ambrotose AO® resulted in an increase in resting levels of TEAC (p = 0.02) and ORAC (p < 0.0001). No significant change was noted in resting levels of MDA, H2O2, or NOx (p > 0.05). Exercise resulted in an acute increase in TEAC, MDA, and H2O2 (p < 0.05), all which were higher at 0 minutes post exercise compared to pre exercise (p < 0.05). No condition effects were noted for exercise related data (p > 0.05), with the exception of ORAC (p = 0.0005) which was greater at 30 minutes post exercise for Ambrotose AO® compared to placebo. CONCLUSION: Ambrotose AO® at a daily dosage of 4 capsules per day increases resting blood antioxidant capacity and may enhance post exercise antioxidant capacity. However, no statistically detected difference is observed in resting or exercise-induced oxidative stress biomarkers, in quality of life, or in GXT time to exhaustion.
Assuntos
Antioxidantes/metabolismo , Suplementos Nutricionais , Estresse Oxidativo/efeitos dos fármacos , Adulto , Antioxidantes/administração & dosagem , Biomarcadores/análise , Teste de Esforço , Feminino , Humanos , Peróxido de Hidrogênio/sangue , Lipídeos/sangue , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Óxidos de Nitrogênio/sangue , Cooperação do PacienteRESUMO
BACKGROUND: In the present investigation we compared blood epinephrine (EPI), norepinephrine (NE), free fatty acids (FFA) and glycerol concentrations in response to a capsaicinoid supplement or placebo in healthy adults before and after acute exercise. METHODS: Twenty subjects ingested a placebo or supplement (Capsimax, OmniActive Health Technologies; 2 mg capsaicinoids in a microencapsulated matrix) with one week separating conditions. Fasting blood samples were collected during each visit; 30 minutes following a rest period and before placebo or supplement intake (Pre); 2 hours post intake (2 hr); one minute following the cessation of 30 minutes of exercise performed at 65% of maximal heart rate reserve (2.5 hr); 90 minutes following the cessation of exercise (4 hr). Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure were recorded at all times. RESULTS: A time effect was noted for HR, SBP, and DBP (p < 0.05), with HR and SBP higher at 2.5 hr compared to Pre (due to exercise) and DBP lower at 2.5 hr compared to Pre. No interaction or condition effects were noted for EPI, NE, FFA, or glycerol (p > 0.05). However, a time effect was noted for all variables (p < 0.0001), with values higher than Pre at 2.5 hr for EPI and glycerol, at 2 hr and 2.5 hours for FFA, and at 2 hr, 2.5 hr, and 4 hr for NE (p < 0.05). In terms of percent change from Pre, glycerol was higher with Capsimax than for placebo at 4 hr (p = 0.011) and FFA was higher with Capsimax than for placebo at 2 hr (p = 0.025) and at 2.5 hr (p = 0.015). CONCLUSION: Ingestion of low dose (2 mg) Capsimax was associated with an increase in blood FFA and glycerol at selected times post ingestion, as compared to placebo. However, Capsimax had no differing effect on EPI or NE compared to placebo. Lastly, no difference was noted in HR, SBP, or DBP between placebo and Capsimax.
Assuntos
Fármacos Antiobesidade/uso terapêutico , Capsaicina/análogos & derivados , Suplementos Nutricionais , Epinefrina/sangue , Lipólise/efeitos dos fármacos , Norepinefrina/sangue , Administração Oral , Adulto , Fármacos Antiobesidade/efeitos adversos , Biomarcadores/sangue , Capsaicina/efeitos adversos , Capsaicina/uso terapêutico , Estudos Cross-Over , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Epinefrina/metabolismo , Exercício Físico , Ácidos Graxos não Esterificados/sangue , Feminino , Glicerol/sangue , Humanos , Masculino , Microesferas , Norepinefrina/metabolismo , Sobrepeso/dietoterapia , Canais de Cátion TRPV/agonistas , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: 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 ad libitum 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.
Assuntos
Restrição Calórica/métodos , Doenças Cardiovasculares/prevenção & controle , Terapias Complementares , Dieta Vegetariana , Nível de Saúde , Adulto , Afeto , Pressão Sanguínea , Índice de Massa Corporal , Proteína C-Reativa/análise , Restrição Calórica/efeitos adversos , Restrição Calórica/psicologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Colesterol/sangue , Terapias Complementares/efeitos adversos , Terapias Complementares/psicologia , Dieta Vegetariana/efeitos adversos , Dieta Vegetariana/psicologia , Estudos de Viabilidade , Feminino , Humanos , Insulina/sangue , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Fatores de Risco , Resposta de Saciedade , Adulto JovemRESUMO
UNLABELLED: We have recently noted that ingestion of dietary lipid (in the form of heavy whipping cream) leads to greater oxidative stress than dietary carbohydrate (in the form of dextrose), when consumed in isocaloric amounts. OBJECTIVE: In the present investigation we attempted to replicate our work and also to determine the oxidative stress response to dextrose and lipid meals of two different kilocalorie (kcal) amounts. DESIGN: Nine young (22 +/- 2 years), healthy men consumed in a random order, cross-over design one of four meals/drinks: dextrose at 75 g (300 kcals), dextrose at 150 g (600 kcals), lipid at 33 g (300 kcals), lipid at 66 g (600 kcals). Blood samples were collected Pre meal, and at 30 min, 60 min, 120 min, and 180 min post meal. Samples were assayed for glucose, triglycerides (TAG), malondialdehyde (MDA), and hydrogen peroxide (H2O2). Area under the curve (AUC) was calculated for each variable, and a 4 x 5 ANOVA was utilized to further analyze data. RESULTS: A meal x time effect (p = 0.0002) and a time effect was noted for glucose (p < 0.0001; 30 min > Pre, 1 hr, 2 hr, and 3 hr). The dextrose meals primarily contributed to this time effect. No other effects were noted for glucose (p > 0.05). A meal effect was noted for TAG (p = 0.01; 66 g lipid meal > 75 g and 150 g dextrose meals). No other effects were noted for TAG (p > 0.05). An AUC effect was noted for MDA (p = 0.04; 66 g lipid meal > 75 g and 150 g dextrose meals). A meal x time effect (p = 0.02) and a meal effect was noted for MDA (p = 0.004; 66 g lipid meal > 75 g and 150 g dextrose meals). No time effect was noted for MDA (p = 0.72). An AUC effect was noted for H2O2 (p = 0.0001; 66 g lipid meal > 33 g lipid meal and 75 g and 150 g dextrose meals). A meal x time effect (p = 0.0002), a meal effect (p < 0.0001; 66 g lipid meal > 33 g lipid meal and 75 g and 150 g dextrose meals), and a time effect was noted for H2O2 (p < 0.0001; 2 hr > Pre, 30 min, and 1 hr; 3 hr > Pre). The time effect for H2O2 was primarily influenced by the 66 g lipid meal. CONCLUSIONS: These data indicate that 1) minimal oxidative stress is observed following ingestion of dextrose loads of either 75 g or 150 g, or a lipid load of 33 g and 2) lipid ingestion at 66 g leads to greater oxidative stress than lipid at 33 g or dextrose at either 75 g or 150 g. Hence, in a sample of young and healthy men, only 66 g of lipid (taken in the form of heavy whipping cream) leads to a significant increase in blood oxidative stress, as measured by MDA and H2O2.
Assuntos
Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/efeitos adversos , Glucose/administração & dosagem , Glucose/efeitos adversos , Estresse Oxidativo , Período Pós-Prandial , Adulto , Análise de Variância , Área Sob a Curva , Biomarcadores/sangue , Glicemia/análise , Estudos Cross-Over , Gorduras na Dieta/metabolismo , Glucose/metabolismo , Humanos , Peróxido de Hidrogênio/sangue , Cinética , Masculino , Malondialdeído/sangue , Triglicerídeos/sangue , Adulto JovemRESUMO
Nitric oxide dietary supplements are extremely popular within the sport and bodybuilding community. Most products contain l-arginine, for which there is no direct evidence that oral L-arginine increases circulating nitric oxide or blood flow. A new molecule (2-[nitrooxy]thyl 2-amino-3-methylbutanoate) is being marketed as a sport supplement for purposes of delivering "real nitric oxide" to the circulation. In the present study, we measured the acute effects of this supplement on blood nitrate/nitrite and hemodynamic variables. Ten resistance trained men (26 ± 4 years old; 8 ± 6 years of resistance exercise training) reported to the laboratory in random order after a 10-hour overnight fast on 2 occasions separated by 1 week and were provided the supplement (2-[nitrooxy]ethyl 2-amino-3-methylbutanoate) or placebo. Heart rate and blood pressure were recorded, and venous blood samples were collected before and at 5, 15, 30, and 60 minutes after complete breakdown of the supplement (5 minutes post intake) or placebo. Blood samples were assayed for plasma nitrate/nitrite. No interaction (p = 0.99), condition (p = 0.18), or time (p = 0.98) effects were noted for plasma nitrate/nitrite, with values remaining nearly identical across time for placebo (â¼27 µmol·L(-1)) and increasing a maximum of â¼6.7% (from 32.9 to 35.1 µmol·L(-1)) at the 15-minute collection period for the supplement. In regards to hemodynamic variables, no interaction, condition, or time effects were noted for heart rate, systolic, or diastolic blood pressure (p > 0.05), with values near identical between conditions and virtually unchanged across time. These findings indicate that 2-(nitrooxy)ethyl 2-amino-3-methylbutanoate has a small effect on increasing circulating nitrate/nitrite and does not cause any change in hemodynamic variables within the 1 hour postingestion period in a sample of resistance trained men.
Assuntos
Suplementos Nutricionais , Hemodinâmica/efeitos dos fármacos , Nitratos/sangue , Doadores de Óxido Nítrico/administração & dosagem , Óxido Nítrico/metabolismo , Nitritos/sangue , Treinamento Resistido , Valina/análogos & derivados , Adulto , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Nitratos/administração & dosagem , Valina/administração & dosagem , Adulto JovemRESUMO
BACKGROUND: We have recently reported that the dietary supplement Meltdown increases plasma norepinephrine (NE), epinephrine (EPI), glycerol, free fatty acids (FFA), and metabolic rate in men. However, in that investigation measurements ceased at 90 minutes post ingestion, with values for blood borne variables peaking at this time. It was the purpose of the present investigation to extend the time course of measurement to 6 hours, and to include women within the design to determine if sex differences to treatment exist. METHODS: Ten men (24 +/- 4 yrs) and 10 women (22 +/- 2 yrs) ingested Meltdown or a placebo, using a randomized, cross-over design with one week separating conditions. Blood samples were collected immediately before supplementation and at one hour intervals through 6 hours post ingestion. A standard meal was provided after the hour 3 collection. Samples were assayed for EPI, NE, glycerol, and FFA. Five minute breath samples were collected at each time for measurement of metabolic rate and substrate utilization. Area under the curve (AUC) was calculated. Heart rate and blood pressure were recorded at all times. Data were also analyzed using a 2 (sex) x 2 (condition) x 7 (time) repeated measures analysis of variance, with Tukey post hoc testing. RESULTS: No sex x condition interactions were noted for AUC for any variable (p > 0.05). Hence, AUC data are collapsed across men and women. AUC was greater for Meltdown compared to placebo for EPI (367 +/- 58 pg x mL(-1) x 6 hr(-1) vs. 183 +/- 27 pg x mL(-1) x 6 hr(-1); p = 0.01), NE (2345 +/- 205 pg x mL(-1) x 6 hr(-1) vs. 1659 +/- 184 pg x mL(-1) x 6 hr(-1); p = 0.02), glycerol (79 +/- 8 microg x mL)-1) x 6 hr(-1) vs. 59 +/- 6 microg x mL(-1) x 6 hr(-1); p = 0.03), FFA (2.46 +/- 0.64 mmol x L(-1) x 6 hr(-1) vs. 1.57 +/- 0.42 mmol x L(-1) x 6 hr(-1); p = 0.05), and kilocalorie expenditure (439 +/- 26 kcal x 6 hrs(-1) vs. 380 +/- 14 kcal x 6 hrs(-1); p = 0.02). No effect was noted for substrate utilization (p = 0.39). Both systolic and diastolic blood pressure (p < 0.0001; 1-16 mmHg), as well as heart rate (p = 0.01; 1-9 bpm) were higher for Meltdown. No sex x condition x time interactions were noted for any variable (p > 0.05). CONCLUSION: Ingestion of Meltdown results in an increase in catecholamine secretion, lipolysis, and metabolic rate in young men and women, with a similar response for both sexes. Meltdown may prove to be an effective intervention strategy for fat loss, assuming individuals are normotensive and their treatment is monitored by a qualified health care professional.
Assuntos
Fármacos Antiobesidade/administração & dosagem , Cafeína/administração & dosagem , Catecolaminas/sangue , Suplementos Nutricionais , Metabolismo Energético , Lipólise , Sinefrina/administração & dosagem , Ioimbina/administração & dosagem , Tecido Adiposo , Análise de Variância , Área Sob a Curva , Biomarcadores/sangue , Misturas Complexas/administração & dosagem , Estudos Cross-Over , Ingestão de Energia , Epinefrina/sangue , Ácidos Graxos não Esterificados/sangue , Feminino , Glicerol/sangue , Humanos , Masculino , Norepinefrina/sangue , Obesidade/prevenção & controle , Aptidão Física , Inquéritos e Questionários , Adulto JovemRESUMO
Two prevalent origins of oxidative stress in Western society are the ingestion of high-fat meals and the performance of strenuous exercise. The purpose of this investigation was to compare the magnitude of increase in blood oxidative stress following acute feeding and acute exercise. Twelve exercise-trained men consumed a high-fat meal or performed 1 of 3 exercise bouts (steady-state aerobic; high-intensity, moderate-duration interval sprints; maximal intensity, short-duration interval sprints) in a random order, crossover design. Blood was collected before and at times following feeding and exercise. Samples were analyzed for trigylcerides, malondialdehyde (MDA), hydrogen peroxide (H(2)O(2)), advanced oxidation protein products (AOPP), nitrate/nitrite (NOx), trolox-equivalent antioxidant capacity (TEAC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). A significant condition effect was noted for MDA (p = 0.01), H(2)O(2) (p < 0.0001), and AOPP (p = 0.0006), with values highest for the meal condition. An increase of 88%, 247%, and 96% was noted from pre- to post-feeding for MDA, H(2)O(2), and AOPP, respectively. A condition effect was also noted for TEAC (p = 0.04) and CAT (p = 0.05), with values lowest for the meal condition (TEAC) and the meal and aerobic exercise condition (CAT). NOx, SOD, and GPx were relatively unaffected by feeding and exercise, while MDA, H(2)O(2), and AOPP experienced little change from pre- to postexercise (p > 0.05). These results illustrate that the magnitude of blood oxidative stress following a high-fat meal is significantly greater than that elicited by either aerobic or anaerobic exercise in a sample of exercise-trained men.
Assuntos
Dieta Hiperlipídica/métodos , Gorduras na Dieta/sangue , Exercício Físico/fisiologia , Estresse Oxidativo/fisiologia , Esforço Físico/fisiologia , Adulto , Produtos da Oxidação Avançada de Proteínas/sangue , Biomarcadores/sangue , Catalase/sangue , Cromanos/sangue , Estudos Cross-Over , Gorduras na Dieta/administração & dosagem , Glutationa Peroxidase/sangue , Humanos , Peróxido de Hidrogênio/sangue , Masculino , Malondialdeído/sangue , Nitratos/sangue , Nitritos/sangue , Período Pós-Prandial , Superóxido Dismutase/sangue , Triglicerídeos/sangue , Adulto JovemRESUMO
Coenzyme Q10 (CoQ10) plays an important role in bioenergetic processes and has antioxidant activity. Fifteen exercise-trained individuals (10 men and 5 women; 30-65 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 (R(2) = 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.
Assuntos
Exercício Físico , Estresse Oxidativo/efeitos dos fármacos , Ubiquinona/análogos & derivados , Vitaminas/farmacologia , Administração Oral , Adulto , Idoso , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Peróxido de Hidrogênio/sangue , Ácido Láctico/sangue , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Efeito Placebo , Ubiquinona/sangue , Ubiquinona/farmacologiaRESUMO
BACKGROUND: 1,3-dimethylamylamine (a constituent of geranium), alone and in combination with caffeine, is widely used within dietary supplements. We have recently determined the hemodynamic effects of 1,3-dimethylamylamine and caffeine alone and in combination, using a single ingestion study. However, no study has determined the hemodynamic effects of these ingredients following chronic use. Moreover, no study has determined the effects of these ingredients on bloodborne variables related to health and safety. Therefore, the purpose of this investigation was to assess the hemodynamic and hematologic profile of two different dietary supplements containing 1,3-dimethylamylamine and caffeine (in addition to other ingredients), before and after two weeks of daily intake. METHODS: 7 men (24.9 ± 4.2 yrs) ingested the dietary supplement Jack3d™, while 4 men and 2 women (22.5 ± 1.8 yrs) ingested the dietary supplement OxyELITE Pro™ once per day for two weeks. On days 1 and 15, resting heart rate (HR), systolic (SBP), and diastolic (DBP) blood pressure were measured and rate pressure product (RPP) was calculated. Fasting blood samples were analyzed for complete blood counts, comprehensive metabolic panel, and lipid panel. These tests were done prior to ingestion of supplement. On days 1 and 15 following blood collection, subjects ingested the assigned supplement (2 servings) and HR, SBP, DBP, and RPP were recorded at 30, 60, 90, and 120 minutes post-ingestion. RESULTS: After 14 days of treatment, resting HR, SBP, DBP, and RPP were not increased (P > 0.05). No significant changes were noted in any measured bloodborne variable, with the exception of an increase in fasting blood glucose with ingestion of Jack3d™ (P = 0.02). In response to acute intake of the supplements, HR, DBP, and RPP were not increased statistically (P > 0.05). SBP was increased with OxyELITE Pro™ (P = 0.03), but not with Jack3d™ (P = 0.09). Compared to pre-ingestion and in general, both supplements resulted in an increase in SBP, DBP, and RPP from 5%-15%, with a peak occurring at the 60 or 90 minute post-ingestion time. CONCLUSION: Acute ingestion of OxyELITE Pro™, but not Jack3d™, results in an increase in SBP. Chronic intake of two servings per day of OxyELITE Pro™ or Jack3d™ over a 14 day period does not result in an elevation in resting HR, SBP, DBP, or RPP. No significant changes are noted in any measured bloodborne variable following 14 days of ingestion, with the exception of blood glucose with Jack3d™. Longer term intervention studies inclusive of larger sample sizes are needed to extend these findings.
RESUMO
BACKGROUND: We have recently noted an acute increase in circulating free fatty acids and glycerol, as well as resting metabolic rate, when men and women ingested the dietary supplement OxyELITE Pro™ in a single dose. We have also noted a reduction in appetite when subjects were treated with this supplement for 14 consecutive days. It is possible that such findings may favor body weight and fat loss over time. Therefore, the purpose of the present study was to determine the effects of this dietary supplement on weight loss and associated markers using an eight week intervention. METHODS: Exercise-trained subjects were randomly assigned in double blind manner to ingest either the dietary supplement (n = 16; aged 22.8 ± 0.7) or a placebo (n = 16; 22.5 ± 0.5) every day for eight weeks. Body weight, body composition, skinfold thickness, serum lipids, and appetite were measured as the primary outcome variables. As measures of supplement safety, a complete blood count and comprehensive metabolic panel were performed, and resting heart rate and blood pressure were measured (pre and post intervention). RESULTS: No interactions or main effects were noted for our primary outcome measures (P > 0.05). However, when comparing pre and post intervention values for the supplement, significant decreases were noted in appetite, body weight, body fat percentage, and skinfold thickness (P < 0.05), while increases were noted for total and HDL-C, as well as for resting heart rate (P < 0.05). No changes were noted for placebo from pre to post intervention (P > 0.05), with the exception of an increase in HDL-C (P < 0.05). Blood pressure and bloodborne safety variables were not differently impacted by supplement or placebo (P > 0.05), with the exception of monocytes, for which an interaction effect was noted (P = 0.04). CONCLUSION: These data indicate that the dietary supplement OxyELITE Pro™ may assist in weight and body fat loss in a sample of exercise-trained men and women. The supplement does not result in any adverse effects pertaining to resting blood pressure or bloodborne markers of safety; however a small increase in resting heart rate is observed.
RESUMO
BACKGROUND: Dietary supplements are often marketed to increase lipolysis and thermogenesis, with the proposed end result being weight loss and body fat reduction. It was the purpose of the present investigation to study the acute effects of a weight/fat loss supplement within a sample of healthy human subjects. METHODS: Twelve subjects (men 24.8 ± 4.3 yrs; women 22.8 ± 0.4 yrs) ingested a dietary supplement (OxyELITE Pro™) or a placebo, on two separate days in a double-blind, cross-over design. Blood samples were collected immediately before ingestion, and at 60 and 120 minutes post ingestion, and analyzed for plasma glycerol and free fatty acids (FFA). Breath samples were collected immediately before ingestion and at 30, 60, 90, and 120 minutes post ingestion, for a measure of kilocalorie expenditure using indirect calorimetry. Area under the curve (AUC) was calculated. Heart rate and blood pressure were recorded at all times and rate pressure product (RPP) was calculated. RESULTS: AUC was greater for supplement compared to placebo for glycerol (22.74 ± 1.98 µg · mL(-1) · 2 hr(-1) vs. 15.76 ± 1.36 µg · mL(-1) · 2 hr(-1); P = 0.001), FFA (1.62 ± 0.07 mmol · L(-1) · 2 hr(-1) vs. 0.78 ± 0.12 mmol · L(-1) · 2 hr(-1); P < 0.0001), and kilocalorie expenditure (149 ± 7 kcal · 2 hr(-1) vs. 122 ± 8 kcal · 2 hr(-1); P = 0.005). Heart rate (P = 0.02), systolic blood pressure (P < 0.0001), and RPP (P = 0.002) were higher for supplement compared to placebo. CONCLUSION: Ingestion of OxyELITE Pro™ resulted in an increase in blood markers of lipolysis, as well as metabolic rate, during a two-hour post ingestion time period. An increase in hemodynamic variables was also observed. These findings are in reference to a sample of healthy men and women who were naïve to treatment with the dietary supplement. Additional work is needed to determine if the acute changes observed here would persist with chronic use of the supplement and possibly lead to weight/body fat loss over time.
RESUMO
UNLABELLED: Exercise has been noted in some, but not all, studies to elicit an oxidative stress. The discrepancy in findings may be related to differences in exercise intensity across protocols, as well as to differences in training status of participants. PURPOSE: We compared blood oxidative stress biomarkers in exercise-trained men after three different bouts of exercise of varying intensity and duration, as well as a nonexercise condition. METHODS: On different days, men (n = 12, 21-35 yr) performed aerobic cycle exercise (60 min at 70% HR reserve) and cycle sprints (five 60-s sprints at 100% maximum wattage obtained during graded exercise testing and ten 15-s sprints at 200% maximum wattage obtained during graded exercise testing). Blood was collected before and 0, 30, and 60 min after exercise and analyzed for malondialdehyde, hydrogen peroxide (H(2)O(2)), advanced oxidation protein products, and nitrate/nitrite (NO(x)). As indicators of antioxidant status, Trolox equivalent antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase were measured. RESULTS: No differences were noted in malondialdehyde, H(2)O(2), advanced oxidation protein product, or NO(x) between conditions or across time (P > 0.05). Antioxidant capacity was generally highest at 30 and 60 min after exercise and lowest at 0 min after exercise. CONCLUSIONS: In trained men, and considering the limitations of the current design (e.g., inclusion of selected oxidative stress and antioxidant biomarkers measured in blood only), strenuous bouts of exercise do not result in a significant increase in blood oxidative stress during the 1-h postexercise period. These findings may be related to attenuation in reactive oxygen species production as an adaptation to chronic exercise training and/or a protective effect of the antioxidant system in response to acute strenuous exercise.
Assuntos
Sangue/metabolismo , Exercício Físico/fisiologia , Estresse Oxidativo/fisiologia , Adulto , Produtos da Oxidação Avançada de Proteínas/sangue , Antioxidantes/análise , Biomarcadores/sangue , Catalase/sangue , Glutationa Peroxidase/sangue , Humanos , Peróxido de Hidrogênio/sangue , Masculino , Malondialdeído/sangue , Nitratos/sangue , Nitritos/sangue , Superóxido Dismutase/sangue , Adulto JovemRESUMO
BACKGROUND: The purpose of this study was to investigate the acute effects of a nutritional supplement containing a proprietary blend of Phellodendron and Crape Myrtle on serum glucose and insulin in response to a modified oral glucose tolerance test (OGTT). METHODS: Using a randomized, double-blind, cross-over design, 10 exercise-trained, non-diabetic men reported to the lab in a 10 hour fasted state, on two different mornings separated by 1-2 weeks, and were subjected to an OGTT by ingesting a 75 gram dextrose solution. Fifteen minutes prior to the OGTT subjects ingested either a dietary supplement containing a blend of Phellodendron and Crape Myrtle (SUPP) or a placebo (PLA). Blood samples were collected before ingestion of the SUPP or PLA and at 15, 30, 45, 60, and 75 minutes post-ingestion of the dextrose load. Samples were analyzed for serum glucose and insulin. RESULTS: In relation to serum glucose, a condition effect was noted (P = 0.01), with values lower for SUPP compared to PLA. In relation to serum insulin, a trend for a condition effect was noted (P = 0.06), with values lower for SUPP compared to PLA. CONCLUSION: These findings indicate that acute ingestion of a dietary supplement containing a blend of Phellodendron and Crape Myrtle can lower the serum glucose response to a modified OGTT, while resulting in a non-significant attenuation in insulin response. These data are specific to a small sample of exercise-trained, non-diabetic men.
RESUMO
BACKGROUND: Several isolated ingredients have been proposed to increase growth hormone (GH) release, including Chlorophytum borivilianum and Velvet bean. A combination of these two ingredients has been packaged within an investigational dietary supplement. It was the purpose of the present investigation to determine the impact of acute ingestion of this supplement on circulating GH in healthy, exercise-trained men. METHODS: Fifteen men ingested the dietary supplement on two different days, separated by one week. Blood was collected from subjects before ingestion of the supplement and at 20, 40, 60, 80, 100, and 120 minutes post ingestion. GH was analyzed in serum samples using an ELISA method. Values for GH for each subject, at each collection time, were averaged over both test days and used in the main analysis. RESULTS: Serum GH increased over time, with higher values at 60 minutes (1.56 ± 0.65 ng · mL(-1); P = 0.04; +767%), 80 minutes (1.76 ± 0.69 ng · mL(-1); P = 0.02; +878%), and 100 minutes (1.48 ± 0.62 ng · mL(-1); P = 0.05; +722%) compared to pre ingestion (0.18 ± 0.04 ng · mL(-1)). A great deal of subject variability existed in the area under the curve (AUC) for GH, with pooled values ranging from 0.49 to 61.2 ng · mL(-1) · 2 hr(-1.) CONCLUSION: Acute ingestion of an investigational dietary supplement containing the active ingredients Chlorophytum borivilianum and Velvet bean results in an increase in circulating GH in exercise-trained men. Additional placebo controlled investigations are needed to extend these findings. Moreover, studies are needed to determine if chronic use of such supplementation leads to favorable changes in health-related parameters associated with increased circulating GH.
RESUMO
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.
RESUMO
BACKGROUND: 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. METHODS: 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. RESULTS: A decrease was noted in MDA (0.66 ± 0.0.03 vs. 0.56 ± 0.02 µmol L-1; p = 0.004), while H2O2 demonstrated 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-1 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). CONCLUSION: 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).