Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ATHLETICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,423 records · Page 79Linked to original sources
PubMed1998

Relationship between muscle fiber pennation and force generation capability in Olympic athletes.

The thickness (TBmt) and fiber pennation angle (TBpen) of triceps brachii as well as isokinetic force developed during elbow extension were measured in Olympic athletes to investigate the relationship between muscle fiber pennation and force generation capability. The subjects were male members of the 1996 Japanese Olympic team who competed in seven different events; 9 wrestlers, 16 soccer players, 11 sprinters, 5 judo athletes, 7 gymnasts, 9 rowers and 18 baseball players. The TBmt and TBpen, measured by a B-mode ultrasound, ranged between 29 mm and 50 mm and between 11 degrees and 30 degrees, respectively, and on average were larger in the judo athletes, wrestlers and gymnasts compared to the other groups. A significant correlation (r=0.580, p < 0.05) was found between TPpen and TBmt per unit of the upper arm length, and so the observed event-related differences in TBpen tended to reflect the differences in TBmt. The isokinetic forces relative to the cross-sectional area (CSA) estimated from TBmt, measured at two constant velocities of 1.05 rad/s (F1.05/CSA) and 3.14 rad/s (F3.14/ CSA), were negatively correlated to the CSA; r=-0.617 (p < 0.05) for F1.05/CSA and r=-0.635 (p < 0.05) for F3.14/CSA. In addition, low but significant negative correlations existed between TBpen and both F1.05/CSA (r=-0.365, p < 0.05) and F3.14/ CSA (r=-0.336, p <0.05). Even when the effect of TBpen was statistically normalized, the F1.05/CSA and F3.14/CSA were still negatively correlated to the CSA, r=-0.530 (p < 0.05) for F1.05/ CSA and r=-0.561 (p < 0.05) for F3.14/CSA. Therefore, at least in the Olympic athletes tested in this study, the magnitude of the pennation angles reflects muscle size, but it does not seem to be a factor that explains extensively the lower F/CSA in athletes with large muscle size.

Adult↗
PubMed1996

Athlete's heart: a meta-analysis of the echocardiographic experience.

Meta-analytical techniques were applied to selected echocardiographic reports on athlete's heart. The combined analysis of studies in which competitive long-distance runners were compared to matched nonathletic control subjects, revealed a 10% (p < 0.001) higher left ventricular internal diameter in the runners, an 18% (p < 0.001) thicker wall and an 8% (p < 0.05) greater relative wall thickness. In strength athletes these differences averaged +2.5% (p < 0.01), +15% (p < 0.05) and +12% (p < 0.05), respectively, and in cyclists +9% (p < 0.05), +29% (p < 0.01) and +19% (p <0.05). When compared to their respective controls, left ventricular mass was larger by 64% (p < 0.01) in cyclists, 48% (p < 0.001) in runners and 25% (p < 0.05) in strength athletes. There were no differences in left ventricular systolic or diastolic function at rest. The meta-analysis of longitudinal studies, in which athletes were assessed in active and inactive periods, suggested that at least part of the differences from nonathletes can be ascribed to the training per se. In conclusion, the classification of left ventricular hypertrophy in athletes as eccentric or concentric has to be considered as a relative concept, most likely related to the fact that training regimens and/or sports activities are not exclusively of the dynamic or static type but comprise both components to a variable extent.

Adaptation, Physiological↗
PubMed1986

Lipoprotein and lipid profiles of elite athletes in Olympic sports.

The aim of this work was to obtain an insight into the influence exerted upon plasma lipid parameters by high quality physical training in different specialties of nine Olympic sports. We compared the concentrations of serum cholesterol (TC), total lipids (TL), triglycerides (TG), HDL, LDL, VLDL, and % distribution of HDL, LDL, and VLDL of elite athletes (n = 127, age = 22.0 +/- 3.2 yrs) participating in regular training for over 3 years (2-4 h/day), separated into 11 groups of athletic specialties, with those obtained from a group of selected sedentary controls (n = 26, age = 25.3 +/- 4.5 yrs). We also compared the lipoprotein ratio factor (RF) values TC/HDL and LDL/HDL. The athletic disciplines examined were football, basketball, volleyball, boxing, wrestling, judo, sailing, skiing (slalom), track (two groups), and throwing-jumping. Football, volleyball, judo, SD and LD running, and the total sum of athletes had significantly higher HDL than the controls. Football, basketball, volleyball and all the disciplines taken together showed significantly lower LDL. Boxing, judo, and LD running had significantly lower VLDL and volleyball, SD, and LD running significantly lower %VLDL. Volleyball had significantly lower TL, boxing and volleyball lower TC, while judo, boxing, SD and LD running had lower TG. Sailing had significantly lower %HDL and higher %LDL and TL than the controls; wrestling, skiing, and throwing-jumping did not differ. In all the athletes taken together, VO2 max or relative body weight, with respect to HDL and TC/HDL, were found to be slightly correlated (r = 0.30, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Enlargement of the right heart in the endurance athlete: a two-dimensional echocardiographic study.

M-mode echocardiographic studies of endurance-trained athletes have provided conflicting data for right ventricular (RV) dimensions and no data for right atrial (RA) size. Since two-dimensional echocardiography provides a more accurate measurement of the RV and RA, it was employed together with M-mode echocardiography to evaluate 12 male endurance athletes and 12 sedentary controls matched for body size and age. All subjects were screened by history, physical examination, ECG, and maximal exercise testing. RV and RA areas were planimetered in the apical four-chamber view while displaying maximal chamber sizes. Athletes had significantly greater left ventricular (LV) wall thickness (P less than 0.01), LV area (P less than 0.001), and left atrial (LA) area (P less than 0.01). They also had greater RV area (P less than 0.01), RV wall thickness (P less than or equal to 0.05), and RA area (P less than or equal to 0.01). Maintained proportionality of the cardiac chamber dimensions in the athletes was shown by similar ratios of right-to-left ventricular areas, right-to-left atrial areas, and right-to-left ventricular wall thicknesses in both groups. The symmetry of the greater athlete's heart differs from most pathological conditions which have heterogeneous effects on specific cardiac chambers.

Adult↗
PubMed1983

Pattern of venous lactate and pyruvate after submaximal exercise in athletes training in different disciplines.

The differences in the distribution pattern of muscle fiber types between short-, middle-, and long-distance runners are well known. Since slow- and fast-twitch muscle fibers have different oxidative and glycolytic activities, lactate and pyruvate blood concentrations are expected to behave differently in athletes training in different sports disciplines after short exercise. Twenty-four well-trained athletes participated in the present study. The purpose of the investigation was to examine lactate and pyruvate blood concentrations during a 5-min treadmill exercise test at 6 km/h with a slope of 10% in short-, middle-, and long-distance runners and athletes of other disciplines (nonrunners). The highest and lowest post-exercise lactate and pyruvate levels were found in the short- and long-distance runners, respectively. In contrast to what was found in all other athletes, a decrease of the lactate-pyruvate ratio was observed in the middle-distance runners after exercise. The combination of both aerobic and anaerobic training in these athletes could account for this observation.

Adult↗
PubMed2001

Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes.

OBJECTIVE: The objective was to investigate the role of Helicobacter pylori infection in iron-deficiency anemia (IDA) of pubescent athletes. STUDY DESIGN: Blood sampling and a questionnaire survey were performed on 440 regular high school students and 220 athletes of a physical education high school. Hemoglobin, serum iron, total iron-binding capacity, ferritin, and immunoglobulin G antibody to H. pylori were measured to compare the prevalence of IDA and H. pylori infection in the groups. Nutritional analysis and a questionnaire survey for socioeconomic status were undertaken to compare and control for other risk factors that might influence IDA and H. pylori infection in the groups. In those with IDA coexistent with H. pylori infection, we also determined whether IDA can be managed by H pylori eradication. RESULTS: The prevalence rates of IDA, H pylori infection, and H. pylori -associated IDA in female athletes were higher than in the control group. The relative risk of IDA was 2.9 (95% CI, 1.5 to 5.6) for those with H. pylori infection. Athletes who exhibited H. pylori -associated IDA showed significant increases in hemoglobin, iron, and ferritin levels after H. pylori eradication. The subjects in the control group who were treated orally with iron alone showed no significant changes. CONCLUSION: Adolescent female athletes may have development of H. pylori -associated IDA, which can be managed by H. pylori eradication.

Adolescent↗
PubMed2005

Three independent biological mechanisms cause exercise-associated hyponatremia: evidence from 2,135 weighed competitive athletic performances.

To evaluate the role of fluid and Na+ balance in the development of exercise-associated hyponatremia (EAH), changes in serum Na+ concentrations ([Na+]) and in body weight were analyzed in 2,135 athletes in endurance events. Eighty-nine percent of athletes completed these events either euhydrated (39%) or with weight loss (50%) and with normal (80%) or elevated (13%) serum [Na+]. Of 231 (11%) athletes who gained weight during exercise, 70% were normonatremic or hypernatremic, 19% had a serum [Na+] between 129-135 mmol/liter, and 11% a serum [Na+] of <129 mmol/liter. Serum [Na+] after racing was a linear function with a negative slope of the body weight change during exercise. The final serum [Na+] in a subset of 18 subjects was predicted from the amount of Na+ that remained osmotically inactive at the completion of the trial. Weight gain consequent to excessive fluid consumption was the principal cause of a reduced serum [Na+] after exercise, yet most (70%) subjects who gained weight maintained or increased serum [Na+], requiring the addition of significant amounts of Na+ (>500 mmol) into an expanded volume of total body water. This Na+ likely originated from osmotically inactive, exchangeable stores. Thus, EAH occurs in athletes who (i) drink to excess during exercise, (ii) retain excess fluid because of inadequate suppression of antidiuretic hormone secretion, and (iii) osmotically inactivate circulating Na+ or fail to mobilize osmotically inactive sodium from internal stores. EAH can be prevented by insuring that athletes do not drink to excess during exercise, which has been known since 1985.

Body Weight↗
PubMed2004

Antioxidant vitamin status in high exposure to oxidative stress in competitive athletes.

We conducted a cross-sectional study in 118 well-trained athletes to investigate 'high exposure' to sub-deficient antioxidant status, and consequently to oxidative damage, in relation to estimated daily energy expenditure (EE) and dietary antioxidant intake. Subjects completed 7 d food and activity records. Blood samples were obtained on day 8. Of the athletes 81, 60 and 43% had intakes of vitamins E, C and beta-carotene below two-thirds of the French RDA respectively, which is adjusted for EE (FRDAa). The deficit in vitamin E intake was positively correlated with EE (r 0.51, P<0.0001). All the athletes had normal plasma vitamins E and C and 14% had marginal plasma beta-carotene. Plasma thiobarbituric acid-reactive substances (TBARS) did not increase with increased EE. As evidenced by ANOVA, EE-induced vitamin C intakes increased and consequently led to increased plasma ascorbic acid concentrations. In male athletes, plasma total carotenoids were negatively correlated with plasma TBARS concentrations (r -0.31, P<0.006). The relationship between vitamin C intakes and plasma concentrations was logarithmic (r 0.59, P< 0.0001). To summarize, it is not clear whether vitamin E requirements are overestimated with reference to EE in the FRDAa. Daily requirements for vitamin C do not exceed 200 mg. Our present results could be interpreted as meaning that carotenoids play a protective role as exogenous antioxidants. Carotenoid intakes in athletes must be considered carefully.

Adult↗
PubMed1977

Interdigital athlete's foot: new concepts in pathogenesis.

In our view, interdigital athlete's foot usually begins with invasion of the horny layer by dermatophytes. Because of hot weather, sweating, exercise, or tight shoes, enough moisture accumulates to stimulate an overgrowth of bacteria. Large numbers of normally resident aerobic diphtheroids cause the common wet, macerated type of athlete's foot, while an overgrowth of Gram-negative organisms, such as Pseudomonas and Proteus, is responsible for the more serious cases. The dry, scaly type (dermatophytosis simplex) often alternates with the wet, macerated type (dermatophytosis complex). Flare-ups are common in summer and can be experimentally induced by occlusion of fungus-infected feet. Suppression of bacteria is essential in treating symptomatic athlete's foot. This can be accomplished by exposing the feet to air (eg, wearing sandals) to enhance evaporation of water and prevent the accumulation of excess moisture that stimulates bacterial overgrowth. Topical antibiotics are another approach, with the ideal perhaps being an agent with both broad-spectrum antibacterial and antifungal activity. The newer imidazoles are broad-spectrum compounds but have limited activity against Gram-negative organisms. Our agent of choice, aluminum chloride, combines broad-spectrum antimicrobial activity with chemical drying, a two-pronged attack. We view drying as the decisive element. We doubt that any local treatment can permanently eradicate athlete's foot. Potent antifungal agents can virtually exterminate interdigital dermatophytes, but the inevitable presence of infection in the nails or on the soles assures reinfection. In shoe-wearing populations living in temperate climates, interdigital athlete's foot is mainly a seasonal disease. The various therapies discussed provide a variety of approaches to prevent or ameliorate hot-weather exacerbations.

Humans↗
PubMed1987

Use of anabolic steroids by athletes. Do the risks outweigh the benefits?

The use of anabolic steroids by both competitive and noncompetitive athletes has reached alarming proportions. Although use is most common in bodybuilders and weight lifters, athletes participating in track and field events and football also take the steroids. The recent resurgence in physical fitness awareness has only exacerbated the problem, and the physician needs to acknowledge the potential for abuse in any athlete. Despite the difficulties and ethical problems in designing good controlled studies with high-dose steroids, evidence suggests that steroids do increase muscular strength in certain subgroups of athletes. Unfortunately, numerous side effects and permanent damage may occur, and the athlete may be at risk for the development of fatal liver tumors or cardiovascular disease.

Anabolic Agents↗
PubMed2000

Energy conversion rates during sprinting with an emphasis on the performance of female athletes.

Computed results from a mathematical model of the bioenergetics of sprinting, which incorporates a three-equation representation of anaerobic metabolism, were compared with measured distance-time data for female athletes from the finals of the 100-m event at the World Championships of 1987. The computed results closely model the performance of the competitors over the course of the entire race. The three main contributions to anaerobic metabolism were investigated and comparisons were made between male and female sprinters. Whereas the time constants for adenosine triphosphate (ATP) and phosphocreatine utilization for the two sexes were found to be similar, for oxygen-independent glycolysis the time constants of the female athletes were found to be higher. The maximum powers generated by female athletes during ATP conversion and glycolysis were only slightly lower than the figures found for male athletes, but the value for phosphocreatine utilization was substantially lower. The lower value for phosphocreatine utilization might explain the more pronounced fall-off in running speed over the latter stages of a race that female athletes experience in comparison with men. Although anaerobic sources dominate energy provision for both male and female sprinters, the calculations show that the latter make greater use of aerobic energy supplies.

Adenosine Triphosphate↗
PubMed2005

Contaminated nutritional supplements--legal protection for elite athletes who tested positive: a case report from Germany.

A significant proportion of nutritional supplements manufactured worldwide contain non-listed contaminations with anabolic-androgenic steroids (AAS), whose ingestion may lead to positive doping test results. This will lead to the suspension of, and sanctions against, the athlete, since this group of active substances is prohibited by the anti-doping code of the World Anti-Doping Agency as well as by sports associations not connected with this agency. Considerable financial losses are often the consequence for a banned athlete. Based on an amendment to the law governing the manufacture and prescription of drugs (AMG) in Germany in 1997 and an increasingly extensive interpretation of the term "drug" by the Federal Supreme Court, preparations containing anabolic steroids or their precursors are to be classified as drugs and, therefore, are subject to compulsory declaration as stated by the AMG. If this obligation is not adhered to, the result may be a claim for damages by the athlete against the manufacturer of a preparation, if the athlete took the preparation thinking it was harmless as judged by the Anti-Doping regulations, but was then found to be positive in doping tests. The judges in the first case before the county court in Stuttgart decided in favour of the claim for damages with respect to lost bonuses, loss of earnings and accrued legal costs by a soccer player who tested positive and was therefore suspended. Based on the evidence presented, the court came to the decision that the soccer player's positive test result was due to the ingestion of nutritional supplements containing non-listed AAS. This procedure could set a precedent for other states to demonstrate that athletes who had tested positive due to contaminated nutritional supplements are not without legal protection.

Anabolic Agents↗
PubMed2006

Assessment of hydration status by urinary analysis of elite junior taekwon-do athletes in preparing for competition.

The aim of this study was to assess over time the hydration status of taekwon-do athletes during a preparatory camp. Measures of urine osmolality, conductivity, specific gravity and colour were made on the first urine sample passed by the participants (n = 32) in the morning before breakfast. The urinary measurements were made on samples collected at the beginning of the camp, 5 days later and one day before competition. Body mass was also measured at the same instants. Body mass (mean +/- s) was essentially the same on each of the measurement days (62.6 +/- 12.2, 62.7 +/- 12.3 and 62.2 +/- 12.6 kg, respectively). Mean urine osmolality at the beginning of the camp was relatively high (998 +/- 171 mOsmol . kg-1), suggesting that a significant number of the athletes were already hypohydrated. However, no significant differences were detected in urine osmolality at the three time points during the study. There were no significant differences in any of the four methods of urine analysis during the study (P > 0.05). The average values for all samples were 989 +/- 205 mOsmol . kg-1 for osmolality, 25.5 +/- 6.7 mS . cm-1 for conductivity, 1.017 +/- 0.010 g . cm-3 for specific gravity and 4 +/- 1 arbitrary units for colour. Correlation analysis between the different methods suggested moderately good agreement (correlation coefficient = 0.5-0.7) between all four measurement techniques (P < 0.01). The coefficients of variation for these techniques were relatively low (CV = 11.8 - 35.0%). The results of this study suggest that some of the taekwon-do athletes were slightly hypohydrated in the morning on each of the test days, but there was no evidence to suggest that most of the athletes further restricted their fluid intake to make weight. In addition, it appears that each of the four methods used gave essentially the same estimate of hydration status of these athletes.

Adult↗
PubMed1996

In search of invariant athletic behaviour in sport: an example from championship squash match-play.

Analysis of competitive sport performance from a priori observation is frequently used to prepare an athlete for a future contest. This practice necessarily assumes that the observed athletic behaviours are invariant, in that the data from an earlier contest apply to the next. We report different analyses of championship squash matches from 1987 and 1988 in search of such invariance and thus a general signature of athletic behaviour. The results show that once the preceding condition to an athletic response (shot) becomes more detailed, by either accounting for where on court the previous shot was played to, or by pairing the previous shot with its own antecedent, the corresponding response becomes more predictable (P > 0.25). This is especially the case for a squash champion when the forehand and backhand characteristics of his shot response are accounted for. The finding that the champion is more consistent if his forehand and backhand shot responses to a preceding shot are analysed separately, shows that the level of analytic detail is an important consideration if the derived information from sport analysis is to prepare an athlete reliably for future sport competition. Finally, we consider sport competition from an ecological perspective with regard to the natural organization and stability of non-linear systems in an attempt to explain the empirical data.

Adult↗
PubMed1990

Assessing the institutional choice process of student-athletes.

The primary purpose of this investigation was to determine the relative importance of the attributes that student-athletes use when determining their choice of a university. A second purpose was to compare previous athletic institutional choice studies with the results of this study to determine if the most important attributes were similar and to compare and contrast methodologies. Six hundred five Division I student-athletes (344 baseball players and 261 softball players) from all eight national geographic regions of the NCAA participated in this study. The experimental procedure was based on Information Integration Theory and a 2(10) fractional factorial design that resulted in 32 "choice sets." These choice sets were composed of universities described by 10 attributes. This framework required that the student-athletes choose from among three university profiles, thereby realistically simulating the decision process. The results for the aggregate sample show that the "Amount of Scholarship" attribute was the most important factor in the institutional choice process. Many demographic variables were analyzed (sex, race, amount of scholarship received as a freshman, amount of perceived financial need, self-reported grade-point average, questionnaire completion procedures, in-state/out-of-state status, NCAA region, and rank in high school) in conjunction with the choice set data in a post-hoc framework. The results for a subset of these variables are reported in this paper; differences (in the order of importance of the attributes) were found among groups. A primary finding of this study is that a student-athlete's perceived financial need has a critical impact on the institutional choice process.(ABSTRACT TRUNCATED AT 250 WORDS)

Choice Behavior↗
PubMed2003

Reflected appraisals and perceived importance of significant others' appraisals as predictors of college athletes' self-perceptions of competence.

This study examined the reflected appraisal process with college athletes (N = 325). Specifically, the study tested (a) the relative influence of the reflected appraisals of mothers, fathers, coaches, and teammates (i.e., how athletes perceive these others view their ability) on athletes' self-perceptions of competence, and (b) whether the importance placed on these significant others as sources of competence information moderated the relationship. Based on a factor analysis, composite variables were formed representing the reflected appraisals of the athletes' parents (i.e., father, mother) and the reflected appraisals of sport-others (i.e., coach, teammates). Regression analyses revealed that the reflected appraisals of parents (beta = .21) and sport-others (beta = .55) predicted self-perceptions of competence (p < .05, R2 = .45). Follow-up analyses determined that the reflected appraisal of sport-others was a significantly stronger predictor. Hierarchical regression analyses revealed that the interaction of reflected appraisals and the importance of significant others did not significantly add to the prediction of self-perceptions of competence (p > .05, deltaR2 = .01) beyond the independent effects of these constructs. Results are discussed in terms of the reflected appraisal process and the influence of significant others on athletes' self-perceptions.

Adolescent↗
PubMedDate not supplied

Skeletal maturity and body size of teenage Belgian track and field athletes.

Attained skeletal maturity (TW2 RUS method), skeletal maturity relative to chronological age, and body size of national-level Belgian track and field athletes 15 to 18 years of age were considered. Among the 47 male athletes, 29 (62%) were skeletally mature, while 15 (52%) of the 29 female athletes were skeletally mature. There appeared to be a predominance of skeletally mature individuals among male sprinters and jumpers, while a majority of female sprinters were not skeletally mature. Both skeletally mature and immature individuals were rather evenly represented in the other track and field categories, with the exception of female throwers, who were skeletally mature. Mean statures and weights of skeletally mature and immature 16-, 17-and 18-year-old male athletes did not differ significantly, though the skeletally mature tended to be heavier. In contrast, the skeletally mature female athletes, on the average, were taller and heavier than the skeletally immature, although the differences among the small groups were not statistically significant.

Adolescent↗
PubMedDate not supplied

Relative expansion of extracellular water in elite male athletes compared to recreational sportsmen.

This study reports total body hydration and water distribution between the extracellular water (ECW) and the intracellular water (ICW) of a group of 15 elite male athletes compared with a group of 15 male subjects practising the same sport at 'amateur' level. Total body water (TBW) and ECW were assessed by means of deuterium and bromide dilution techniques respectively. Both TBW and body hydration were significantly higher in elite athletes than in non-competitive subjects (52.3 +/- 5.0 vs 46.1 +/- 4.2 litres p < 0.001 and 63.2 +/- 1.9 vs 60.2 +/- 1.9% body weight, p < 0.003 respectively). Likewise, both ECW the ratio of ECW to TBW were significantly higher in athletes than in control subjects (20.7 +/- 2.9 vs 16.1 +/- 1.8 litres, p < 0.0001 and 0.40 +/- 0.06 vs 0.35 +/- 0.03, p < 0.005 respectively). ICW was similar in both groups but the ICW to ECW ratio was significantly higher in the athletes compared to the recreational sportsmen (0.67 +/- 0.16 vs 0.54 +/- 0.07, p < 0.01). These data suggest that assumptions regarding the chemical composition of the standard human body may not be valid in elite athletes.

Adult↗