J Sport Sci Med
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The placebo effect, a positive outcome resulting from the belief that a beneficial treatment has been received, is widely acknowledged but little understood. It has been suggested that placebo responsiveness, the degree to which an individual will respond to a placebo, might vary in the population. The study aimed to identify placebo-responsive participants from a previously published paper that examined the effects of caffeine and placebos on cycling performance. ⋯ Finally, data suggested that the personality factors of extroversion, agreeableness, openness and neuroticism may relate to placebo responding. Placebo effects such as pain tolerance and fatigue resistance might be experienced by a percentage of participants but might not always be manifest in objective measures of performance. Key pointsBeliefs can have both positive (placebo) and negative (nocebo) effectsPlacebo effects may be experienced both objectively and subjectivelyCertain personality traits may be related to placebo respondingA multi-method approach may best elucidate placebo effects in sport.
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The purpose of the study was to assess the effects of sodium citrate ingestion on the metabolic response to exercise and performance in a 1500-m competitive run in trained female middle-distance runners in field conditions. Seventeen athletes (mean (± SD) aged 18.6 ± 2.5 years, VO2max 55.2 ± 7.6 ml·kg(-1)·min(-1)) competed in two 1500-m races following ingestion of 0.4 g·kg(-1) body mass of sodium citrate (CIT) and placebo (PLC - 1.0% solution of NaCl). The two substances, CIT and PLC were administered in 800 ml of solution in a randomly assigned double-blind crossover manner. ⋯ The limited data on the effects of sodium citrate ingestion on the metabolic response to exercise and performance suggest that it may have all the benefits of sodium bicarbonate without the associated negative side effects. We assessed the effects of sodium citrate ingestion on the metabolic response to exercise and performance in a 1500-m competitive run in trained young female middle-distance runners. The results suggest that sodium citrate induces an increase in water retention before exercise and may modify carbohydrate metabolism in high intensity running, but does not improve performance in 1500-m competitive run in female middle-distance runners.
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The purpose of this research was to study the influence of motivational climate perceived in peers and basic psychological needs (competence, autonomy and relatedness) on self-determined motivation and enjoyment in exercise. A sample comprised of 394 non- competitive physical exercisers, 156 women and 238 men aged between 16 and 54 (M = 21.64, SD = 7. 18), completed the Motivational Climate Perceived in Peers Scale, Scale of Motivational Mediators in Physical Activity, Behavioural Regulation in Exercise Questionnaire-2 and Physical Activity Enjoyment Scale. A correlation analysis between the variables studied, a confirmatory factor analysis (CFA) and structural equation analysis were performed. ⋯ There were no significant associations between the ego-involving peer motivational climate and psychological needs. Needs for competence and relatedness positively predicted self-determined motivation. Self-determined motivation positively predicted enjoyment.