ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Osteoid osteomas are small, benign bone tumors most commonly located in the proximal femur or tibia. The classic presentation is localized pain increasing in severity at night, and relieved by the use of anti-inflammatory medications. In a young athlete complaining of foot pain, many conditions should be included in the differential diagnosis. A case of osteoid osteoma of the os calcis in a teenage basketball player is presented.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Twenty subjects were randomly assigned to: 1) prophylactic ibuprofen (N= 5) [400 mg TID initiated 4 h before collection of baseline data and strenuous eccentric exercise bout], 2) therapeutic ibuprofen (N= 5) [400 mg TID initiated 24 h after baseline], 3) placebo (N= 5), or 4) control (N= 5). Muscle soreness perception, plasma creatine kinase, knee extensor torque, and EMG of the quadriceps were evaluated at baseline, 24, and 48 h. The prophylactic ibuprofen group had between 40 and 50% less muscle soreness perception and significantly less decline in isometric, concentric, and eccentric torque at 24 h compared with the other three groups (P< 0.05). At 48 h both prophylactic and therapeutic ibuprofen had significantly less muscle soreness perception and decline in torque than the placebo and control groups (P< 0.05). There was no difference between the amount of muscle damage between the four groups at 24 and 48 h. Vastus medialis and lateralis EMG magnitude decreased across time. Vastus lateralis EMG magnitude had significantly less decline from baseline for prophylactic ibuprofen compared with the other three treatments at 24 h, while both prophylactic and therapeutic ibuprofen had significantly less decline at 48 h. These data indicate that a prophylactic dosage of ibuprofen does not prevent CK release from muscle, but does decrease muscle soreness perception and may assist in restoring muscle function.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Peak oxygen uptake (VO2peak) of patients on maintenance hemodialysis is very low. Exercise training performed during, or “on” dialysis, and at other times, “off” dialysis, both improve VO2peak. Equivalence of these approaches has not been shown, nor have the physiologic factors limiting VO2peakbeen clarified in these patients. We hypothesized that hemodialysis docs not acutely alter the cardiovascular response to peak exercise, and further that anemia and a low peak heart rate limit VO2peak. Ten patients with end-stage renal disease (ESRD) performed cycle ergometry to peak exercise. Peak oxygen uptake measured immediately prior to dialysis was compared with predicted values, and with measurements obtained during the second 30 min of dialysis. The determinants of VO2peakwere compared with previously reported norms. “Off” dialysis. VO2peakfor nine of 10 patients was below the 95% confidence limit for normals. Their cardiovascular response to peak exercise was unchanged by 30–60 min of hemodialysis. Stroke volume was similar to that of normals; however, peak heart rate was 77% of predicted, and hematocrit was 27% (at rest). Peak exercise mixed-venous oxygen content was 3.6 ml O2ml.dl−1blood, similar to values reported for athletes. These findings show that up to 1 h of dialysis minimally effects VO2peak, and imply that low oxygen delivery limited VO2peakin these patients.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Recurrent idiopathic exercise-related syncope in the young athlete is often a challenging and frustrating condition. Vasovagally mediated hypotension and bradycardia is believed to be a common, but difficult to prove, cause of this form of syncope. This study evaluated the usefulness of head-upright tilt table testing in the evaluation and management of young athletes with recurrent idiopathic exercise-related syncope. Twenty-four trained young athletes (12 male, 12 female mean age 18 ± 3.4 yr) with recurrent unexplained exercise-related syncope were evaluated by use of an upright tilt table test for 30 min, with or without an infusion of isoproterenol (1–3 μg. min−1given intravenously) in an effort to provoke bradycardia, hypotension, or both. Ten control patients with no history of syncope were also studied. Syncope occurred in 10 patients (41%) during the baseline tilt and in nine patients (37%) during the isoproterenol infusion (total positives 79%). Seventeen patients who had positive test results eventually became tilt table negative with pharmacotherapy, and over a mean follow-up period of 23 ± 7 months, no further syncopal episodes have occurred. Two patients refused pharmacotherapy and have continued to experience syncope. We conclude that head-upright tilt table testing combined with isoproterenol infusion is useful in the diagnosis of vasovagal syncope in young athletes with recurrent exercise related syncope, and in the evaluation of prophylactic pharmacotherapy.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The purpose of the present study was to correlate data on calf muscle metabolism using31P nuclear magnetic resonance spectroscopy with measurements of whole body maximal oxygen consumption and maximal power output, and to determine whether the combination of these data could be used to predict athletic ability. Experiments were performed in a 2.35 Tesla, 35 cm diameter electromagnet on the leg muscle of sedentary human subjects (N= 6) and groups of athletes trained for endurance (cross-country skiers,N= 7) or strength performance (downhill skiers,N= 5). The exercise protocol consisted of successive plantar flexions performed at graded fractions of the maximal voluntary contraction (MVC). The results obtained from NMR investigation (changes in content of inorganic phosphate: Pi, phosphocreatine: PC and muscle ATP, and intracellular pH) were then compared with those of maximal O2consumption (VO2max) and maximal power (MP). When the data on athletes were compared with those obtained on sedentary subjects, the curves illustrating the relationship between the imposed load and the Pi/PC ratio were significantly shifted toward high output power for a given Pi/PC value. It also appeared from this study that specific training in force development (downhill skiing) induced a slighter decrease in PC level than for endurance (cross-country skiers) despite improvement in physical performance. A slight but significant intracellular acidification was observed in the muscles of sedentary subjects and downhill skiers for contraction at, respectively, 50% and 80% of MVC, but not in the skeletal muscles of cross-country skiers. The comparison of the NMR results with those given by VO2maxand MP revealed that the energetic response of muscle to exercise was not always closely related to the global capacity for endurance or for short and intense effort. However, the breakdown of the population into specific training groups using principal components analysis showed that global and local parameters could be combined to discriminate aptitude in the performance of either an endurance or a brief and intense exercise.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

At the onset of dynamic exercise there is an almost instantaneous heart rate (HR) acceleration caused by neural activation of central motor areas (central command) and stimulation of mechanoreceptors located in the moving limbs. Aiming to identify the independent contribution of the peripheral mechanism to the initial HR response to exercise, 29 subjects performed two 4-s bouts of unloaded cycling (active (AEx) and passive (PEx)) on an adapted commercial tandem bicycle. PEx was accomplished by having a staff member pedal while sitting on the rear seat. The HR was continuously measured from electrocardiographic tracings. Records of electromyography (EMG) were obtained in a small sample of subjects during the exercise tasks. The number of pedal rotations was very similar (mean ± SE) (AEx = 7.4 ± 0.3, PEx = 7.5 ± 0.2,P= 0.455), determining significant HR changes (P< 0.001) that were similar in the two types of exercise (AEx from 92 to 125 bpm: 35.9% increase; PEx from 87 to 111 bpm: 27.6% increase;P= 0.185). Contrasting to AEx, no muscle contraction was observed by EMG during PEx, suggesting that central command was absent. We concluded that independent activation of mechanoreceptors can promote HR acceleration at the onset of dynamic exercise.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Two experiments were done at rest to examine gastric residue and secretion volume and electrolyte composition after ingestion of beverages of varying composition. In the first experiment the effects of two different sport drinks, one isotonic (7% carbohydrate, primarily sucrose) (I) and one hypertonic (18% carbohydrate, primarily maltodextrin) (H), and a control beverage (0.08 g.1−1aspartame in water) (C) on titratable acid, pH, osmolality, gastric emptying and secretion volume, and Na+, K+, and Cl−content were measured. In a second experiment five solutions were tested all containing 150 g.1−1maltodextrin, with 28 meq.1−1Na+(low Na), 140 meq.1−1Na+(high Na), 28 mcq.I-1K+(K), or 140 meq.1-1Na+and 28 meq.1−1K+(high NaK). Beverages H and C, and distilled water (W) were also tested. Samples were taken via a nasogastric tube. A dye dilution technique for serial sampling was employed to determine beverage and secretion volumes. After receiving a bolus of 8 ml.kg−1body weight, samples of gastric residue were taken at 0, 10, 20, 30, 40, 60, and 80 min. Gastric secretion of Na*, K+, and Cl−was fairly constant despite large differences in beverage composition. Changes in gastric residue pH, titratable acid, osmolality, and electrolyte composition reflected the increasing proportion of the residue that was from gastric secretions. The effects of varying concentrations of Na+and K+(in a 150 g.1−1maltodextrin solution) on gastric emptying were not significant. The high carbohydrate concentration and/or the large volume ingested may have overridden any effect of sodium or potassium. No differences were observed between W and C. Secretion was decreased in these two solutions versus all the others. Although nonsignificant, there was a trend for greater secretion in H versus the other carbohydrate containing solutions in experiment 2. This may be a result of the higher pH maintained after ingestion of this beverage.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Studies of body composition and feed efficiency were conducted on 80 male Sprague-Dawley rats to determine how exercise training alters growth and development in iron deficient animals. Animals were assigned to iron deficient (ID) or control (CN) diets (AIN-76, w/o cellulose), and sedentary (SD) or exercised groups [EX, treadmill running, 4 d.wk−1, 90 min.d−1, 65% maximal oxygen consumption (VO2max), maintained for 6 or 12 wk. The ID diet caused a sustained moderate iron deficiency (Hb 7.2 ± 0.2 g.dl−1). Iron deficient animals failed to increase maximal oxygen consumption despite the rigorous training program, though training resulted in 25% or 35% higher VO2maxin 6− or 12-wk CN rats. At 6 wk. IDEX animals had significantly (33%) lower growth rates than did IDSD animals, which in turn were 22% less than CNs. Overall, exercise did not alter relative amounts of protein in the carcass (% total mass); however, a significant interaction between diet and treatment duration was evident in IDEX animals at 12 wk, who had lower %protein than CNEX-12 or IDSD-6 rats. Training decreased fat 11% in CN at 6 wk but not 12 wk, and 20% in IDs at 12 wk but not 6 wk, Feed efficiency and energy intake were 28% and 12% lower in IDEX animals than CNEX at 6 wk. Training increased caloric intake in CNEX animals but not IDEX animals at 6 and 12 wk, Thus, exercise training exacerbates the poor growth associated with ID through alterations in both food intake and feed efficiency in early phases of training, but adaptation is apparent.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

For physical activity surveys that would identify relations to chronic diseases, quality of life, and longevity, the method of choice remains the questionnaire, especially if it can be standardized and administered in uniform fashion to large populations. A sample questionnaire derived largely from epidemiological experience with the Harvard Alumni Health Study is presented that requests anthropometric estimates; physician-diagnosed diseases by year of onset; contemporary physical activities including walking, stair-climbing, and recreational pursuits; food-frequency data that estimate nutrient values and caloric intakes; and social habits affecting health. The questionnaire presents opportunities for cross-sectional, retrospective, and prospective studies. Personal characteristics, physical activities, and other elements of lifestyle may be used as predictor or outcome variables in testing specific hypotheses. Representative surveys are described that have validated and used questionnaires of various complexities, some complemented by measures of physiological fitness. The epidemiological survey questionnaire, when properly designed and administered, can measure effectively energy intake, energy retention, energy expenditure, physiological fitness, quality of life, and health maintenance.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID