297 research outputs found

    Nutritional peak week and competition day strategies of competitive natural bodybuilders

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    Bodybuilders utilize peaking strategies in a bid to fine-tune their aesthetics for competition day. The most prevalent peaking strategies utilized by natural bodybuilders are unreported in the current literature. Eighty-one (M - 59, F - 22) natural bodybuilders were recruited from competitions during the 2016 and 2017 British Natural Bodybuilder Federation seasons. Competitors completed a 34-item questionnaire designed to investigate peaking and contest day strategies. The questionnaire listed commonly utilized peaking strategies and provided additional space for qualitative information. Analysis of the data indicated that carbohydrate (CHO), water and sodium manipulation were the most commonly utilized peak week strategies. The consumption of high glycemic index CHO was the most common competition day strategy. Only 6.2 % of competitors reported following their regular diet the week prior to competition. The CHO manipulation strategies were similar to classical CHO loading, whereby bodybuilders attempt to maximize muscle glycogen concentrations. Furthermore, bodybuilders attempted to remove superfluous water by exploiting the diuretic/polyuria effect associated with water loading/restriction. The potentially deleterious effects of peaking on bodybuilders' health is considered and the efficacy of these strategies to enhance appearance is discussed. The findings of the present investigation are likely to be of interest to bodybuilders and their coaches

    Efficacy of methylcobalam in to normalise elevated homocysteine of vitamin B12 deficient vegetarians: a double blind placebo control study

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    Vegetarians are known to be deficient in vitamin B12, due to a lack of dietary animal products,which can elevate plasma total homocysteine (tHcy). Elevated total tHcy can render vegetarians susceptible to cardiovascular disease (CVD).There are a limited number of published studies in relation to the efficacy of methylcobalamin to normalise plasma tHcy of vitamin B12 deficient vegetarians.The primary objective of the present study was to explore the relationship between supplementary oral methylcobalamin and levels of tHcy of vitamin B12 deficient vegetarians; to reduce the risk of developing primary CVD. A randomised double blind placebo controlled pilot study was conducted to monitor and analyse baseline and post treatment levels of plasma tHcy, 49 volunteer vegetarians were recruited to participate in this study. Statistical analysis employing SPSS software indicated that methylcobalamin reduced mean baseline plasma tHcy of 15.5 μmolL-1 (n=39) to a mean plasma tHcy level of 8.4 μmolL-1 (P < 0.001). In a second group that contained details of ten withdrawn participants, which was conducted on an ‘Intention to Treat’ (ITT) basis, indicated that methylcobalamin was shown to be reduced from a mean baseline plasma tHcy of 14.7 μmolL-1(n=49)to a mean plasma tHcy level of 9.1 μmolL-1 (P < 0.001).The findings of the study have the potential to alert vegetarians of the possible risk of becoming vitamin B12 deficient, and to help avoid the risk of developing homocysteine related CVD. The quality data obtained in the study will allow an accurate sample size to be calculated for a future definite clinical study

    An investigation into the pragmatic diets of vegetarianism: the results of a pilot study

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    Published recommended various classifications of vegetarian diets are widespread across the globe, but few published articles if any report on the types of foods actually consumed by vegetarians in general. The primary objective was to elucidate this aspect of vegetarianism, analysis of food consumption over a fourteen day period, with respect to the various manifestations of vegetarianism, was undertaken in the form of a pilot study to indicate the contents of these diets as compared with recommended daily allowances (RDA) and adequate intake (AI) values. Five lactovegetarians, twenty lactoovovegetarians and fourteen vegans, were recruited. The study included a detailed analysis of the vegetarian participants’ diet, through the compilation of an individual diet diary. Statistical analysis employing Microsoft Excel software was conducted to determine the outcome of the vegetarians’ diets, with each mean nutrient and mean dietary energy value compared against RDA and AI. Analysis of the participants’ diet diaries indicated somewhat unexpectedly a failure to meet the RDA and AI for several important nutrients. Furthermore, the daily metabolizable energy level for all classifications of vegetarians was lower than the recommended AI for daily energy requirements. Whilst it is generally accepted that vegetarianism can lead to a healthy lifestyle, the findings of this research indicate that vegetarianism participants may be at risk of deficiency of certain nutrients that could potentially lead to chronic medical conditions. The statistical findings obtained in the study will allow an accurate sample size to be calculated for each important item for future large definitive studies

    Plasma total homocysteine status of vegetarians compared with omnivores: a systematic review and meta-analysis

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    There is strong evidence indicating that elevated plasma total homocysteine (tHcy) levels are a major independent biomarker and/or a contributor to chronic conditions, such as CVD. A deficiency of vitamin B12 can elevate homocysteine. Vegetarians are a group of the population who are potentially at greater risk of vitamin B12 deficiency than omnivores. This is the first systematic review and meta-analysis to appraise a range of studies that compared the homocysteine and vitamin B12 levels of vegetarians and omnivores. The search methods employed identified 443 entries, from which, by screening using set inclusion and exclusion criteria, six eligible cohort case studies and eleven cross-sectional studies from 1999 to 2010 were revealed, which compared concentrations of plasma tHcy and serum vitamin B12 of omnivores, lactovegetarians or lacto-ovovegetarians and vegans. Of the identified seventeen studies (3230 participants), only two studies reported that vegan concentrations of plasma tHcy and serum vitamin B12 did not differ from omnivores. The present study confirmed that an inverse relationship exists between plasma tHcy and serum vitamin B12, from which it can be concluded that the usual dietary source of vitamin B12 is animal products and those who choose to omit or restrict these products are destined to become vitamin B12 deficient. At present, the available supplement, which is usually used for fortification of food, is the unreliable cyanocobalamin. A well-designed study is needed to investigate a reliable and suitable supplement to normalise the elevated plasma tHcy of a high majority of vegetarians. This would fill the gaps in the present nutritional scientific knowledge

    Biopsychosocial effects of competition preparation in natural bodybuilders.

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    Bodybuilders are judged on the subjective visual assessment of their muscular size, proportion, and leanness. This case series tracked four drug-free bodybuilders (3 male) during the off-season, pre-competition and recovery phases. This study aimed to comprehensively profile key biopsychosocial changes occurring pre/post competition in a group of British natural bodybuilders. We measured: resting metabolic rate (RMR), body composition (via BIA, ultrasound and sum of 7 skinfolds), lipid profiles, fasted glucose, blood pressure, power output (Wingate), grip strength, and carried out psychometric questionnaires (EAT-26, STAI, BUT) over an eight-month period. Mean weight loss from 5 months (5M) to pre-contest (PRE) was 8.6 +/- 4.1 kg, followed by an increase of 7.9 +/- 1.6 kg two months post contest (POST). The mean RMR of the cohort was stable from 1899 +/- 630 kcal (5M) to 1897 +/- 598 kcal (PRE), before decreasing to 1797 +/- 242 kcal (POST). Mean peak power declined from 770 +/- 113.0 w (5M), to 700.0 +/- 134.4 w (PRE), before increasing to 816.0 +/- 116.2 w (POST). Competition dieting had no effect on EAT-26 or BUT scores, suggesting no body dysmorphic or eating disorder concerns, although trait anxiety was elevated in three out of the four participants throughout the observation. Many of the biopsychosocial changes that occur to bodybuilders as they prepare for competition return to baseline measurements 2 months post competition

    Life Sciences Implications of Lunar Surface Operations

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    The purpose of this report is to document preliminary, predicted, life sciences implications of expected operational concepts for lunar surface extravehicular activity (EVA). Algorithms developed through simulation and testing in lunar analog environments were used to predict crew metabolic rates and ground reaction forces experienced during lunar EVA. Subsequently, the total metabolic energy consumption, the daily bone load stimulus, total oxygen needed, and other variables were calculated and provided to Human Research Program and Exploration Systems Mission Directorate stakeholders. To provide context to the modeling, the report includes an overview of some scenarios that have been considered. Concise descriptions of the analog testing and development of the algorithms are also provided. This document may be updated to remain current with evolving lunar or other planetary surface operations, assumptions and concepts, and to provide additional data and analyses collected during the ongoing analog research program
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