Amphetamine, secobarbital, and athletic performance. III. Quantiative effects on judgment.
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Amphetamine↗
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Results for “Athletic Performance”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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Diet and athletic performance.
Inadequate diet inhibits optimal performance in otherwise well-trained athletes. Controversy exists regarding specific dietary requirements, particularly in the areas of protein and vitamin/mineral supplementation. This article reviews energy substrate utilization, provides an overview of nutrient requirements during exercise, discusses ergogenic aids, and where possible, makes specific dietary recommendations for athletes.
Diet↗
[Instability and impingement of the shoulder of the high performance athlete in overhead stress].
The present prospective study was performed on 89 competitive sportsmen (league players of handball, basketball, volleyball and water polo). The evaluation was based on information obtained from a review of training methods, a standardised anamnestic, physical and sonographic examination directed at pain, function, flexibility and all signs of impingement and instability of the shoulder counted in a score. The incidence of shoulder pain, which handicapped during training and play within the last 6 months was for water polo 60%, handball 40%, volleyball 25% and basketball 3.5%. Analysing these problems we found severe problems predominantly in handball, fewer in water polo or volleyball. According to data obtained from sports with throwing activity we found a high incidence of shoulder disorders. Using basketball players as a control group with less throwing activity our results would suggest that this mechanism seems to be the most important. The high incidence of severe disorders in handball players is additionally caused by traumatic injuries. Ultrasonography shows predominantly incomplete tears of the deep surface of the supraspinatus tendon near to the insertion with exception of the basketball players. Only in 5 shoulders (2.8%) we found the coincidence of clear signs of instability and subacromial pathology. The term "instability impingement" has not proved to be very helpful and has turned out to be far too diffuse to establish a diagnosis.
Acromioclavicular Joint↗
[Performance training in pregnancy. Report of respiratory and cardiovascular physiologic changes in a pregnant high-performance athlete in comparison with a sample of normal pregnant patients].
Against the background of dramatic changes that took place in the history of sports during the past one hundred years, we are today discussing with regard to the compatibility of sport and pregnancy whether the extent of sports activities before pregnancy contributes to the amount of stress tolerated during pregnancy. Animal experimental studies on the effect of physical stress on the foetus cannot always be transferred to man, and hence recommendations made to pregnant women are often purely empirical. The article reports on the results of an examination of a professional woman athlete during pregnancy: Various maternal circulatory and respiratory parameters were recorded in this primigravida of 25 years of age, who had been regularly active as a competitive runner for 12 years, during the 24th week of pregnancy and from the 28th week of pregnancy onwards, at intervals of 14 days and post partum, at rest and during steady-state load on a bicycle ergometer (6 minutes each at 40 and 70 watts load, respectively) and a step-by-step load increasing every minute by 15 watts until attainment of a maternal heart rate of 150 beats per minute. The results were compared with those in a group of pregnant women who had not been competitive sportswomen. During continued training as per schedule up to the 36th week of pregnancy of the athlete, there was hardly any change in performance, and there was a marked difference against the other women. The pulse at rest was lower by a mean of 30 beats in the athlete during pregnancy, clearly indicating maintenance of the economic cardiac mechanism known to occur in trained persons, which produces a greater cardiac output via an increased stroke volume at a lower heart rate. This difference was impressively demonstrated under different loads. Another example of more economic management of an identical load is also seen, for instance, in the lower oxygen uptake and lower respiratory rate. Even at a maternal heart rate of 150 beats per minute the foetus of the athlete did not show any signs of stress under test conditions. In a measurement "at site" during the 38th week of pregnancy under routine and training conditions with relevant sprints and a maternal heart rate increase to more than 170 beats per minute, however, foetal behaviour displaying bradycardia clearly showed the existence of tolerance limits for foetal supply.(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Rejection, motivation and athletic performance: is there a traded player syndrome?
It is widely held that the professional athlete who is traded tends to perform better against the trading team than against other teams. Two psychological explanations for this hypothesis were advanced (a separation-hostility mechanism and an esteem loss-counteraction mechanism). Data were examined for 47 (30) professional baseball players over a 2-yr. (3-yr.) period. Support for the hypothesis was weak across the entire sample; however, some support appeared among players who (a) were traded for the first time, (b) had long tenure with the trading team, (c) were young, and (d) had high ability. Somewhat stronger positive results were found for individuals who met two or more of the conditions favorable to the hypothesis. As predicted, results attenuated over time.
Adult↗
Nutrition and athletic performance.
Energy, CHO and possibly protein needs are higher for athletes than for typical persons. CHO supplementation during and after exercise is important for endurance athletes. A balanced diet, adequate in calories, can meet the vitamin and mineral needs of virtually all athletes. Athletes must be aware of maintaining an optimum hydration status. Intensive nutrition education efforts are needed to combat to combat quackery and fads that are targeted to athletes.
Diet↗
Vitamin supplementation and athletic performance.
Vitamins serve primarily as regulators of metabolic functions, many of which are critical to exercise performance. Depending upon the nature of their sport, e.g., strength, speed, power, endurance, or fine motor control, athletes may use megadoses of various vitamins in attempts to increase specific metabolic processes important to improved performance. Surveys have indicated that most elite athletes do take vitamin supplements, often in dosages greater than 50-100 times the United States Recommended Dietary Allowances. The theoretical basis underlying the use of each vitamin depends upon its specific metabolic function in relation to sport. Vitamin A functions to maintain night vision; thiamin, riboflavin, niacin, and pantothenic acid are all involved in muscle cell energy metabolism; niacin may also block free fatty acid release; pyridoxine is involved in the synthesis of hemoglobin and other oxygen transfer protein; folic acid and vitamin B12 are integrally involved in red blood cell (RBC) development; vitamins C and E are antioxidants, possibly preventing the destruction of the red blood cell membrane during exercise; vitamin D may be involved in muscle cell energetics through its influence on calcium. These are but a few of the possible metabolic functions of vitamins which have been suggested to have ergogenic applications to sport. Research has shown that a vitamin deficiency impairs physical performance. If this deficiency is corrected, performance usually improves. In general, vitamin supplementation to an athlete on a well-balanced diet has not been shown to improve performance. However, additional research with certain vitamins appears to be warranted, such as with the vitamin B complex and fine motor control, and with vitamin E and endurance at high altitudes. Moreover, research with megadose supplementation may also be necessary.
Efficiency↗
Elite endurance athletes and the ACE I allele--the role of genes in athletic performance.
Genetic markers that might contribute to the making of an elite athlete have not been identified. Potential candidate genes might be found in the renin-angiotensin pathway, which plays a key role in the regulation of both cardiac and vascular physiology. In this study, DNA polymorphisms derived from the angiotensin converting enzyme (ACE), the angiotensin type 1 receptor (AT1) and the angiotensin type 2 receptor (AT2) were studied in 64 Australian national rowers. Compared with a normal population, the rowers had an excess of the ACE I allele (P<0.02) and the ACE II genotype (P=0.03). The ACE I allele is a genetic marker that might be associated with athletic excellence. It is proposed that the underlying mechanism relates to a healthier cardiovascular system.
Adult↗
Diet and athletic performance.
There are no dietary tricks or special diets that will give athletes a competitive advantage. Appetite and satiety are sensitive regulators of food intake to meet the caloric requirements of physical conditioning, training, and athletic competition.
Body Composition↗
The dancer as a performing athlete: physiological considerations.
The physical demands placed on dancers from current choreography and performance schedules make their physiology and fitness just as important as skill development. However, even at the height of their professional careers, dancers' aerobic power, muscular strength, muscular balance, bone and joint integrity are the 'Achilles heels' of the dance-only selection and training system. This partly reflects the unfounded view, shared by sections of the dance world, that any exercise training that is not directly related to dance would diminish dancers' aesthetic appearances. Given that performing dance itself elicits only limited stimuli for positive fitness adaptations, it is not surprising that professional dancers often demonstrate values similar to those obtained from healthy sedentary individuals of comparable age in key fitness-related parameters. In contrast, recent data on male and female dancers revealed that supplementary exercise training can lead to improvements of such fitness parameters and reduce incidents of dance injuries, without interfering with key artistic and aesthetic requirements. It seems, however, that strict selection and training regimens have succeeded in transforming dance to an activity practised by individuals who have selectively developed different flexibility characteristics compared with athletes. Bodyweight targets are normally met by low energy intakes, with female dance students and professional ballerinas reported to consume below 70% and 80% of the recommended daily allowance of energy intake, respectively, while the female athlete 'triad' of disordered eating, amenorrhoea and osteoporosis is now well recognised and is seen just as commonly in dancers. An awareness of these factors will assist dancers and their teachers to improve training techniques, to employ effective injury prevention strategies and to determine better physical conditioning. However, any change in the traditional training regimes must be approached cautiously to ensure that the aesthetic content of the dance is not affected by new training techniques. Since physiological aspects of performing dance have been viewed primarily in the context of ballet, further scientific research on all forms of dance is required.
Athletic Injuries↗
Modelling mood states in athletic performance.
Because moods are transitory emotional states that can be influenced by a range of personality and environmental factors, the notion that elite athletes will always tend to produce a so-called iceberg profile of mood, and that less successful performers will not, is open to question. Evidence for such a claim is based principally upon descriptive studies. The present experiment used the POMS inventory as a predictor of cross-country running performance among a group of experienced male athletes. Race times from two competitive events were plotted against each of six mood factors. Using data from race 1, a multiple-regression model--incorporating the interdependence of tension, anger and depression--was able to predict rank order of finishing positions for race 2 with acceptable accuracy (rs = 0.74, P less than 0.01). The present approach differs from the traditional model of mood research in sport in that it provides a prescriptive, rather than a descriptive, focus. Although the model that has been developed appears promising, it is likely that in sports where demands on athletes are very different from those made upon cross-country runners, an alternative model may be required.
Affect↗
Priapism after androstenedione intake for athletic performance enhancement.
Priapism is a relatively rare condition characterized by persistent painful erection of the corpora cavernosum that occurs unrelated to sexual stimulation or desire. It has been associated with cocaine exposure, sickle cell anemia, anticoagulant therapy, neoplastic syndromes, diabetes, and the use of psychotropic medications. Androstenedione is a testosterone precursor used by athletes to enhance performance; the lay press has recently touted this substance as an over-the-counter sexual stimulant. We describe an otherwise healthy man with 2 episodes of priapism after the use of androstenedione. The patient did not have any factors known to precipitate priapism.
Adrenergic alpha-Agonists↗
Sports supplements. Can dietary additives boost athletic performance and potential?
Nutritional sports supplements, many of which are endorsed by professional athletes, are increasing in popularity among casual and adolescent sports enthusiasts, bodybuilders, and weight lifters. Because many people consider nutritional additives to be "natural" and therefore "safe," patients may not consider the possible effects of those substances when taken in high doses or in combination with medications. Drs Rubinstein and Federman present an interesting overview of several sports supplements and examine the consequences and caveats of their use, as well as the reasons for their popularity.
Androstenedione↗
Biomechanics of the musculotendinous unit: relation to athletic performance and injury.
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Athletic Injuries↗
Athens 2004: the pollution climate and athletic performance.
Athens sits in a basin approximately 450 km2 in area, surrounded by mountains and open sea. Anthropogenic emissions in conjunction with the topographical and meteorological conditions can result in high air pollution within the city. The pollutants of concern for athletes competing in Athens 2004 appear to be nitrogen dioxide (NO2), ozone and particulate (PM10) pollution. Exposure to elevated ozone concentrations has been reported to give rise to symptoms that include cough, chest pain, difficulty in breathing, headache, eye irritation and a decrease in forced expiratory volume in one second. All of these effects are likely to impact upon performance, and several studies of cyclists suggest this to be the case. In contrast, the impact of ambient concentrations of NO2 appears to be negligible on normal activities, but at high exercise intensities the impact remains unclear. The use of currently available information and models to predict the effect of ozone and other pollutants on elite athletes is problematical, since such models are based upon significantly lower ventilation rates than those achieved by some elite athletes. In addition, it is already known that the response to ozone can vary somewhat between individuals. Since the individuals who will be competing in Athens are physiologically very different to the participants in most published studies, it is difficult to predict individual responses. There is some evidence to indicate that adaptation to the adverse health and performance effects of ozone can occur, so that performance is partially recovered on re-exposure. The adaptation is not seen in all studies and appears to be dependent on several factors, including the initial sensitivity of the individual to ozone. Antioxidant supplementation has also been shown in some studies to partially ameliorate the adverse effects of ozone by counteracting the oxidative stress mechanism associated with this pollutant. Whether this transfers to performance enhancement per se remains unclear at present. Additional research is required to gain a sound understanding of the effects of a complex mixed air pollution exposure on the pulmonary function and performance of athletes exercising at high work intensities.
Air Pollutants↗
The effect of completed nutrition on the athletes' performance.
The performance capacity, some somatical parameters, the cardiorespiratory system and the anaerobic exertion of 92 athletes were studied in the function of nutrition. The traditional alimentation was completed partly by a complete food and partly by a protein-rich food. In every case in double-blind arrangements placebo was also used. The treatments lasted one month each. Between the effective and placebo treatments one months interval was kept. The complete food contained 40-60 KJ/body mass kg; the protein completion was 0.5-0.7 g protein/body mass kg. On the effect of both treatments the performance improved in more than the half of the examined persons. The increase of lean body mass could be observed mainly after protein treatment. The relative aerobic power increased significantly only after complete food treatment. The work-heart-rate did not change significantly on the effect of the treatments. The data indicate that the traditional alimentation neither qualitatively nor quantitatively can be considered optimal in more than the half of the examined athletes.
Dietary Proteins↗
The role of flexibility in injury prevention and athletic performance: have we stretched the truth?
The use of stretching to prevent injury, off-set muscle soreness, and improve performance has been widely accepted and promoted in sports. However, little or no scientific evidence supports the practice, and recent research suggests that stretching, which increases flexibility beyond that needed for sport-specific movements, may cause injury. This article presents studies that have looked at the effects of stretching on injury and performance. Many earlier studies that showed benefits of stretching did not look at the effects of stretching alone; they also involved general cardiovascular workouts in the experimental but not control groups. More recent research shows that general fitness, rather than stretching, is a more important risk factor in injury prevention. This article also discusses studies of the relationship between joint laxity and injury and the role that stiffness may play in enhancing performance and preventing injury. Overall, the evidence suggests that increasing range of motion beyond function through stretching is not beneficial and can actually cause injury and decrease performance. These findings should be used to challenge common warm-up practices in athletics.
Athletic Injuries↗
Amino acid supplements to improve athletic performance.
This review provides a critical evaluation of the metabolic rationale for the use of individual amino acids as nutritional ergogenic (work-generating) aids in athletes. The conclusion is that in contrast to the claims made on sport nutrition products, branched-chain amino acids do not improve endurance performance, that the evidence that glutamine supplements may improve immune function is rather weak, and that the available commercial supplements contain too little arginine to increase growth hormone levels. No studies have been performed to investigate the claim that tyrosine supplements can improve explosive exercise.
Amino Acids↗