150 research outputs found

    The Antioxidant Role of Glutathione and N-Acetyl-Cysteine Supplements and Exercise-Induced Oxidative Stress

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    An increase in exercise intensity is one of the many ways in which oxidative stress and free radical production has been shown to increase inside our cells. Effective regulation of the cellular balance between oxidation and antioxidation is important when considering cellular function and DNA integrity as well as the signal transduction of gene expression. Many pathological states, such as cancer, Parkinson's disease, and Alzheimer's disease have been shown to be related to the redox state of cells. In an attempt to minimize the onset of oxidative stress, supplementation with various known antioxidants has been suggested. Glutathione and N-acetyl-cysteine (NAC) are antioxidants which are quite popular for their ability to minimize oxidative stress and the downstream negative effects thought to be associated with oxidative stress. Glutathione is largely known to minimize the lipid peroxidation of cellular membranes and other such targets that is known to occur with oxidative stress. N-acetyl-cysteine is a by-product of glutathione and is popular due to its cysteine residues and the role it has on glutathione maintenance and metabolism. The process of oxidative stress is a complicated, inter-twined series of events which quite possibly is related to many other cellular processes. Exercise enthusiasts and researchers have become interested in recent years to identify any means to help minimize the detrimental effects of oxidative stress that are commonly associated with intense and unaccustomed exercise. It is possible that a decrease in the amount of oxidative stress a cell is exposed to could increase health and performance

    Alcohol Consumption: The Good, The Bad, and The Indifferent

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    Dietary ethanol (alcohol) is the most widely consumed drug worldwide. High levels of mortality, morbidity, and social malaise are associated with abuse of alcohol, and increasing numbers of women and youth are abusing alcohol. However, strong epidemiological data demonstrate a U- or J-shaped relationship between volume of alcohol consumed and all-cause mortality or disease burden. Moderate alcohol consumption is associated with a lower risk of all-cause mortality and disease burden than are abstinence and immoderate drinking. A brief review of the absorption, distribution, metabolism, and excretion of ethanol is provided with a discussion of the impact of gender differences. Potential mechanisms by which ethanol, ethanol metabolites, and (or) phytochemicals, as associated with different types of ethanol-containing beverages, are discussed in regards to the beneficial and detrimental impacts they may have on physiological system functioning and mortality or disease burden. Per capita consumption of ethanol-containing beverages varies across geo-political regions worldwide. A more recent research focus is the impact of consumption patterns on consumption volumes as they relate to disease and mortality. Certain drinking patterns moderate overall volume of ethanol consumption. Thus, an emerging approach to the study of alcohol consumption in populations is to consider both the volume and pattern of consumption as they relate to mortality and disease burden. Alcohol consumption patterns among athletes are discussed; physiological implications of alcohol abuse in this population are outlined. Current guidelines for the consumption of alcohol are reviewed. Alcohol consumption guidelines reflect the current scientific understanding of both the benefits of moderate alcohol consumption and the detriments of immoderate alcohol consumption

    Mentors for Beginning College Student-Athletes: A Possible Aid for Academic Success

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    The responsibility of giving scholarship student-athletes a well-rounded start at the collegiate level may be too immense for only coaches and academic advisors to carry out efficiently without additional help. Transferring part of this responsibility to "mentors" who help freshman student-athletes develop basic study habits and time management skills may be one resolution to the "academic vs. athletics" debate. The article discussed the needs of student-athletes and a description of one organization's attempt to give the members of this special population a better foundation early in their academic careers. It considered a mentoring program at Texas A&M in Fall 1990 to pair scholarship athletes with a mentor

    Effects of Dietary Fish-oil Supplement and Acute Eccentric Exercise on Inflammatory Markers during Different Phases of Menstrual Cycle

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    Fish-oil supplementation may play a positive role in inflammation. Matrix Metalloproteinases (MMPs) are important in controlling tumor growth, metastasis, angiogenesis, and inflammation. Several tissue inhibitors of MMPs (TIMPs) are known to regulate the activity of specific MMPs. PURPOSE: To examine the effects of dietary fish-oil supplementation and acute eccentric exercise on MMP-1, -2, -9, and -10 and TIMP-1, -2, -3, and -4 during two different phases of menstrual cycle. METHODS: As a randomized, double-blind, and placebo-controlled design, 22 college-aged women (age= 20.86 ± 1.39 years) were randomly assigned to either a fish oil (FOG, N=11) or a placebo group (PG, N=11). Participants in the FOG ingested 6 capsules of fish oil per day (total 6.0g, containing 2.4g eicosapentaenoic acid and 1.8g docosahexaenoic acid), while the PG took 6 capsules of safflower oil per day for 3 weeks. Participants in each group performed an acute bout of eccentric single-leg exercise (10 sets of 10 repetitions with a 3-min rest between sets at an isokinetic speed of 30⁰/second) during the mid-follicular (MF) and mid-luteal (ML) phases. The leg exercised for the MF phase was randomly selected and the opposing leg exercised during the ML phase. Overnight blood samples were collected at baseline, 6-hr post-exercise (6hr-PE), and 24-hr PE during the MF and ML phases. Data were analyzed by a separate 2 x 2 x 3 ANOVA with repeated measures along with an appropriate post-hoc test for any significant interactions (p \u3c 0.05). RESULTS: A significant interaction effect (p=0.005) in MMP-1 indicated that MMP-1 in the FOG (193.71±21.72 pg/mL) was higher than that of the placebo group (120.79±21.72 pg/mL) during the MF phase. Both TIMP-1 and -3 were significantly higher (p=.043 and p=.037, respectively) in the FOG (68674.71±2238.56 and 3827.12±193.67 pg/mL, respectively) than the placebo group (62119.26±2178.86 and 3238.94±186.73 pg/mL, respectively). CONCLUSION: Acute eccentric exercise did not affect MMPs and TIMPs in healthy, young females. MMP-1 was the only proteinase affected by the menstrual cycle and a decrease in MMP-1 during the ML phase might be related to elevated estradiol levels. Elevated TIMP-1 and -3 following the 3-weeks of fish-oil supplementation suggested a potential anti-inflammatory effect of the fish-oil supplementation by inhibiting activation of MMPs. It is recommended that an extended period of fish oil supplementation be implemented to further examine its anti-inflammatory effect on other inflammatory biomarkers in different sample groups including both pre- and post-menopausal women

    Acute Maltodextrin Supplementation During Resistance Exercise

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    PURPOSE: Most of the research investigating the ergogenic enhancing mechanisms of carbohydrate have been conducted using aerobic based exercise. Therefore, the purpose of this study was to investigate the effects of pre-exercise maltodextrin ingestion on resistance exercise performance, serum insulin, epinephrine, glucose, and muscle glycogen concentrations. METHODS: In a double blind, cross over, repeated measures design, participants completed four sets to failure at 70% of 1-RM with 45s rest on the angled leg press with or without pre-exercise maltodextrin (2g/kg) after a 3hr fast. Serum glucose, epinephrine, and insulin were assessed at baseline, 30 min post-ingestion, immediately after, and 1hr post-exercise with or without carbohydrate supplementation. Muscle glycogen was assessed from biopsy specimens sampled from the vastus lateralis before supplementation, immediately after exercise, and 1hr post exercise under both conditions. RESULTS: There was no main effect of supplement on resistance exercise performance (p=.18). Muscle glycogen concentration decreased across time for both groups (p\u3c.001). There was an interaction in serum glucose decreasing more during exercise in the carbohydrate condition (p=.026). An interaction occurred showing insulin decreased during exercise in the carbohydrate condition (p=.003). Also, there was a main effect of insulin being elevated with carbohydrate consumption (p=.027). Epinephrine was decreased across all time points after carbohydrate ingestion (p=.023). CONCLUSION: Carbohydrate supplementation before resistance exercise did not improve leg press performance to fatigue despite increased metabolic substrate availability. These results indicate that pre-exercise dietary carbohydrate will be utilized preferentially during exercise due to decreased epinephrine, decreased serum glucose, and increased insulin concentrations. However, the increases in glycolytic substrate availability will not increase exercise performance or glycogen content following 1hr of recovery

    Effects of eight weeks of an alleged aromatase inhibiting nutritional supplement 6-OXO (androst-4-ene-3,6,17-trione) on serum hormone profiles and clinical safety markers in resistance-trained, eugonadal males

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    The purpose of this study was to determine the effects of 6-OXO, a purported nutritional aromatase inhibitor, in a dose dependent manner on body composition, serum hormone levels, and clinical safety markers in resistance trained males. Sixteen males were supplemented with either 300 mg or 600 mg of 6-OXO in a double-blind manner for eight weeks. Blood and urine samples were obtained at weeks 0, 1, 3, 8, and 11 (after a 3-week washout period). Blood samples were analyzed for total testosterone (TT), free testosterone (FT), dihydrotestosterone (DHT), estradiol, estriol, estrone, SHBG, leutinizing hormone (LH), follicle stimulating hormone (FSH), growth hormone (GH), cortisol, FT/estradiol (T/E). Blood and urine were also analyzed for clinical chemistry markers. Data were analyzed with two-way MANOVA. For all of the serum hormones, there were no significant differences between groups (p > 0.05). Compared to baseline, free testosterone underwent overall increases of 90% for 300 mg 6-OXO and 84% for 600 mg, respectively (p < 0.05). DHT underwent significant overall increases (p < 0.05) of 192% and 265% with 300 mg and 600 mg, respectively. T/E increased 53% and 67% for 300 mg and 600 mg 6-OXO, respectively. For estrone, 300 mg produced an overall increase of 22%, whereas 600 mg caused a 52% increase (p < 0.05). Body composition did not change with supplementation (p > 0.05) and clinical safety markers were not adversely affected with ingestion of either supplement dose (p > 0.05). While neither of the 6-OXO dosages appears to have any negative effects on clinical chemistry markers, supplementation at a daily dosage of 300 mg and 600 mg for eight weeks did not completely inhibit aromatase activity, yet significantly increased FT, DHT, and T/E
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