摘要:

The vitamin requirement of athletes in training is analyzed within the context of the relative sufficiency of the diet to meet the energy requirement of enhanced training and competition concomitantly with the need to maintain vitamin intake. The danger of a decreased vitamin intake accompanying the ingestion of high‐calorie food products, particularly carbohydrate, is discussed. The value of diet supplementation with vitamin complexes such as aerovit (II vitamins) or a complex of lipoic acid together with eight complementary mineral substances (complivit) is discussed. Experimental evidence for the efficacy of these preparations, taken in the athletic diet, in reducing vitamin deficiency and improving lipid and carbohydrate metabolism is shown.

ISSN:1057-8315    

DOI:10.1080/15438629209517004

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

The anaerobic threshold (AT) was determined noninvasively during incremental exercise on a bicycle ergometer in two groups (N, = 22, N2= 16) of healthy, untrained middle‐aged men (mean age, 31.5±4.8, and 51.8±5.4 years; maximal rate of oxygen consumption (VO2max)was43.3±7–9, and 34.4±8.0 ml‐kg‐1.‐min‐l) using two testing methods simultaneously: ventilatory threshold and heart rate response (the modified Conconi test). The value of selected functional parameters at AT determined by either method showed no significant difference between the two determinations either in absolute or relative terms. A high correlation was found between the value of the functional parameters at the AT estimated by the two methods (p =3 0.005 in all cases). The two methods of AT determination are interchangeable and may be used under the following conditions: The initial exercise intensity is between 40 and 60% of VO2max; the duration of each exercise increment ranges from 30 to 90 seconds; the increments cause a heart rate increase of 4 to 6 beats/min; the total number of exercise increments ranges from 5 to 12. AT determination from heart rate response may also be performed in older subjects (with about a 93% success rate) under laboratory and field conditions.

ISSN:1057-8315    

DOI:10.1080/15438629209517005

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

Little is known about the characteristics of wheelchair marathon competitors in terms of training, dietary habits, and how these factors relate to performance. Questionnaire data and finishing times were obtained from 29 wheelchair marathon racers, including 16 individuals from the United States, 12 from Japan, and 1 from New Zealand. Analysis of variance (ANOVA) and Student's r‐test were used to determine the statistical significance of comparisons between American and Japanese subjects. Pearson's correlation coefficients were computed among some key variables. The mean age of the subjects was 34.2 years, with a standard error (SE) of 9.5; their body mass was 61.1 kg (SE = 2.1), and triceps skinfold thickness was 9.1 mm (SE = 0.8). The finishing times over 42 km ranged from 119 to 357 minutes, with an average of 190.5 minutes (SE = 10.7). The athletes’training duration consisted of a mean of 360 minutes (SE = 37.2) a week in the 3 months prior to the competition. The usual diet of the competitors during training included 1781 Kcal of energy. Average percentages of calories from protein, carbohydrates, fat, and alcohol were 20.3, 52.9, 26.1, and 0.8, respectively. The Japanese consumed more sodium than the Americans (2899 mg versus 1957 mg) but the difference was not significant. The Japanese group trained more using wheelchair rollers and road rolling, but did no swimming, kayaking, or weight training. The Americans spent more time training (406 minutes versus 296 minutes per week). The mean finishing time for the American group was 163 minutes versus 220 for the Japanese group, and this difference was significant with p<0.05.

ISSN:1057-8315    

DOI:10.1080/15438629209517006

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

Seven male competitive runners (maximal oxygen consumption [VO2max] 66.2±3.6 ml.kg‐1‐min‐1) participated in an evaluation of the effect of intense training on the relationships between heart rate (HR), VO2, and running speed. To establish a baseline relationship, subjects twice performed four randomly ordered steady‐state runs at a constant grade of 2.5%, and one maximal graded exercise test, following days of moderate intensity training (approximately 80% of v"O2max). After baseline determination, subjects trained at a high intensity (approximately 90 to 95% of VO2max) for 2 consecutive days. Following the 2 high‐intensity training days, subjects repeated the steady‐state treadmill running and performed another maximal exercise test. After the intense training period, HR was significantly reduced for any given running speed (p<0.05), with a mean reduction for the four running speeds of 154±7 to 149±7 beats/min. Maximal HR was also significantly reduced following the intense training from 193±12 to 190±9 beats/min (p<0.05). Measurements of VO2were unaffected by the acute increase in training intensity. These results suggest that the relationship between HR and V02is affected by increased training intensity. HR may, therefore, not be an accurate indicator of work intensity following high‐intensity efforts.

ISSN:1057-8315    

DOI:10.1080/15438629209517007

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

The 20 members of the Western Australian fast bowling development squad (mean age, 17.9 years), who had previously undergone routine computed tomography (CT) and magnetic resonance imaging (MRI) scans to detect the presence of bony and intervertebral disk abnormalities, acted as subjects for this study. While these radiologic data were being analyzed, these players were filmed both laterally (200 Hz) and from directly above (100 Hz) as their front foot impacted a force platform during the delivery stride of the fast bowling action. On a subsequent trial, kinetic data from the platform were recorded when their back foot impacted the force platform. In addition, these bowlers performed selected physical capacity tests. The occurrence of abnormal radiologic data were then used to group the bowlers (group 1: no abnormal radiologic features from CT or MRI scans; group 2: disk degeneration or bulging on MRI scan; group 3: spondylolysis, spondylolisthesis, or pedicle sclerosis). A Mann‐Whitney U‐rank test was then used to identify any significant differences (p<0.05) between the groups for all dependent variables. Pars interarticularis and intervertebral disk abnormalities were commonly identified in this sample of fast bowlers (55 and 65%, respectively) and all players who had experienced back pain had evidence of a radiologic abnormality. No player with a normal diagnosis complained of pain. The appearance of these features was attributed to a combination of factors rather than a single cause. Bowlers who recorded poorer hamstring or low back flexibility predisposed themselves to a disk abnormality, whereas those who delivered the ball from a high release height relative to their standing height and players who had bowled over several seasons during their growth period were predisposed to a bony abnormality. Furthermore, bowlers who used a technique that combined a front‐on back foot placement and a side‐on shoulder alignment were more likely to present abnormal radiologic features in the lumbar spine.

ISSN:1057-8315    

DOI:10.1080/15438629209517008

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

Ventilation per minute (VE) and percent fractional expired oxygen [FEO2(%)] data were used to determine the work rate at which the ventilatory threshold occurred during an incremental kayak test. Although an exponential curve fitted the ventilation data significantly, a quartic curve was more useful for subjective determination of the ventilatory threshold. A cubic polynomial curve fitted the blood lactate, pH, carbon dioxide pressure, bicarbonate, and base‐excess data from an incremental test on a treadmill, indicating the more complex curvilinear nature of these parameters as exercise intensity increased. This creates difficulties for the objective determination of a training intensity, which is likely to induce optimal training adaptation. In addition, the prescription of training based on a set blood lactate concentration may result in different physiologic stress for different individuals. Heart rate was found to vary little within a range of work rates that induced maximum variation in lactate concentration, creating difficulties in using heart rate to monitor work intensity at higher work rates. Lactate concentration was found to be protocol specific and independent of work rate. Lactate concentration at an equivalent work rate in two different protocols was significantly different.

ISSN:1057-8315    

DOI:10.1080/15438629209517009

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

Hemodynamic responses and hormonal changes induced by lower body negative pressure (LBNP) were measured in bedridden patients with severe disabilities to identify their cardiovascular function. After a control period of 5 minutes supine, each subject underwent a LBNP test of‐20 mmHg for 5 minutes. Disabled patients were classified into two groups: Group HI consisted of the members who had a blood pressure response to LBNP exposure similar to normal control subjects, and group H2 patients displayed a greater reduction in blood pressure than the normal response. Both disabled groups demonstrated a significantly higher level of resting heart rate as well as a smaller stroke volume and cardiac output than normal subjects. Exposure to LBNP in disabled patients produced a smaller decrement in stroke volume and cardiac output than in normal subjects. The expected increase in heart rate for the compensatory effect was not observed in the HI group, and a decreased heart rate lower than resting values was measured in the H2 group. The norepinephrine response of the disabled groups was found to be insufficient compared with normal subjects. It is suggested that cardiovascular deconditioning of disabled patients is caused not only by a decrease in total blood volume, but also by impairment of baroreflex activity both centrally and peripherally due to the patient's extremely prolonged recumbency.

ISSN:1057-8315    

DOI:10.1080/15438629209517010

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629209517003

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor