摘要:

A 21-yr-old male wrestler was studied for 2 months as he trained and dieted for the 1981 Maccabiah Games trials and the 1981 National AAU Wrestling Tournament trials. Measurements of body composition, anthropometry, pulmonary function, muscular strength, serum plasma constituents, and maximal aerobic power were made 53, 31, and 3 d prior to the AAU tournament. Training consisted of two workouts daily, running 3.2–9.7 km each morning and wrestling 1–2.5 h each afternoon. In addition, the subject recorded his weight daily and maintained a log of food consumption. As a result of a low-fat, high-protein, high-carbohydrate diet and continued training, his weight decreased from 54.88 to 50.59 kg while body fat decreased from 4.8 to 1.1%. This loss consisted of 2.21 kg of lean tissue and 2.08 kg of fat tissue. The day prior to AAU competition, an additional 2.73 kg were lost by dehydration to meet the 48.0-kg weight classification. Despite the subject's loss of lean and fat tissue, maximal aerobic power (∼67 ml·min-1·kg-1) and muscular strength were maintained. These findings indicated that this wrestler was able to undergo a weight loss of approximately 8.0% and still maintain a high level of muscular strength and maximal aerobic power.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The effects of aspirin treatment on kidney excretory function were investigated in treadmill-exercised men. Six individuals ran for 30 min at 70% of their maximal oxygen consumption. Exercise tests were conducted for control and aspirin-treated conditions. Aspirin (3.25 g/d) was administered for 3 d prior to testing. Experiments were carried out with the subjects nonhydrated and hydrated (4 ml H2O/kg body weight). Aspirin treatment did not influence the alterations in creatinine clearance, urine volume, osmolar clearance, and/or sodium and potassium excretion seen with exercise. The only effect of aspirin was observed in the recovery samples of the non-hydrated tests in which aspirin treatment significantly decreased urine volume and increased urine specific gravity, osmolality, and the urine/plasma osmolality ratio. These results suggest that aspirin treatment does not have any significant effects on the renal excretory response to short-term moderate exercise.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The effect of pangamic acid (calcium gluconate and N, N-Dimethylglycine) ingestion was examined during short-term maximal treadmill performance on 16 male track athletes. The study was conducted as a double-blind experiment with an experimental group (E) whose members each ingested six 50-mg pangamic acid tablets per day and a control group (C) whose members each ingested six placebo tablets per day for three weeks. The placebo tablets were identical to the pangamic acid tablets in appearance. Subjects were tested by using the Bruce treadmill protocol before and after treatment. The following parameters were examined: maximal heart rate (HR), treadmill time (TM), recovery HR at minutes 1 and 3, and pre-test and post-test blood glucose and lactate levels. Pre-treatment data were 183 bpm (E) and 194 bpm (C) for maximal HR, 16.99 min (E) and 16.49 min (C) for TM, 132.13 mg% (E) and 133.38 mg% (C) for post-test glucose, and 64.63 mg% (E) and 76.13 mg% (C) for post-test lactate. Post-treatment data were 181 bpm (E) and 194 bpm (C) for maximal HR, 17.21 min (E) and 16.83 min (C) for TM, 138.88 mg% (E) and 139.13 mg% (C) for post-test glucose, and 70.88 mg% (E) and 66.58 mg% (C) for post-test lactate. Multivariate analysis of variance (MANOVA) revealed no significant differences (P>0.05) between groups after treatment. It was concluded that ingestion of pangamic acid does not produce significant changes in short-term maximal treadmill performance.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The cardiac dimensions of long-distance runners (LDR), cycle racers (CR), and weight lifters (WL) were determined echocardiographically and were compared with those of control subjects (CS). Left ventricular hypertrophy (LVH) was also assessed from the electrocardiogram. Training information was obtained through a questionnaire. The maximal aerobic performance was assessed on a cycle ergometer.Comparison of the cardiac dimensions revealed that left ventricular mass (LV mass) was significantly increased in LDR and CR as compared to CS. This resulted from thickening of the interventricular septum and left ventricular posterior wall as well as from enlargement of the left ventricular internal diameter. The existence of LVH was confirmed by electrocardiographic investigation. Although the left ventricular wall was enlarged in WL, their LV mass was not significantly increased as compared with CS. These results are in agreement with the training program followed. Weight lifters almost exclusively performed strength training, while LDR and CR were mainly involved in endurance training. The LDR and CR reached significantly higher maximal aerobic performance levels than WL. The present results suggest a close relationship between the type of cardiac enlargement and the training program followed by the athletes.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Plasma catecholamines (Ca) increase over time during prolonged exercise at a constant work rate. Possible reasons for this include hypoglycemia, dehydration, increased perceived exertion, and rising body temperature. In an effort to ascertain the contribution of elevated core temperature on the plasma Ca response to prolonged exercise four trained men were studied under two thermal conditions during 45 min of bicycle exercise (∼60% V2max) and during passive heating. On one testing day each subject was heat-stressed during exercise wearing a nylon pullover shell and cotton pants, (heat stress treatment); on the second day fans were directed on the subjects exercising in a thermoneutral environment (fan treatment). The passive heating experiment was conducted in a hot water bath (41°C). The exercise heat stress treatment produced a higher plasma norepinephrine (NE) concentration (P<0.05) in all subjects than the fan treatment. The plasma epinephrine (E) concentration was not significantly (P>0.05) different during exercise in the heat stress treatment from that found during fan treatment. A rise in rectal temperature (Tre) during passive heating resulted in quantitatively small changes in plasma E and NE. The heat load combined with the exercise task produced an increase in plasma NE concentration greater than the sum of the values measured during exercise in the thermoneutral environment and passive heating. This suggested that the combination of stressors caused an augmentation of the sympathetic nervous system's response. Finally, the added heat load caused changes in plasma NE and little change in plasma E, suggesting a differential Ca response with heat stress.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Anaerobic threshold (AT) and &OV0312;2maxwere determined by automated analysis for 25 members of the 1980 U.S. Olympic Rowing Team during a progressive rowing ergometer exercise to exhaustion. Heart rates and power outputs were also measured to gauge severity of the exercise and to compare with metabolic data. Power increments of 27 W each min were achieved by progressively increasing the brake weight resistance on the ergometer while maintaining a stroke rate of 28–32 strokes/min and spinning the ergometer flywheel at 550 rpm. Anaerobic threshold measurements were determined by observing the onset of the non-linear relationship between &OV0312;o2and &OV0312;E - &OV0312;co2; plots of ΔFEo2and FECO2were also utilized to confirm recorded AT's. A mean AT of 83% of &OV0312;O2max, attests to the high aerobic capacity of oarsmen and supports previous research conducted with these subjects. Power output data indicated that 72% of total power is generated at AT; this substantiates previous energy cost data recorded during simulated rowing during which work was 70% aerobic and 30% anaerobic. High levels of anaerobic thresholds among oarsmen are attributed to the specific nature of training regimens that increase oxidative capacity of muscle fibers and significantly improve the cardiorespiratory transport system. Measurement of heart rate at AT has provided coaches and athletes an objective method of determining the intensity of training sessions.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Six skinfold measurements for male and female athletes (N=456) at the 1976 Montreal Olympic Games were analyzed to identify principal components of fatness and anatomical distribution of fat, i.e., fat patterning. As in non-athletes, two principal components were evident among the athletes. All skinfolds were correlated positively with the first component, which was termed fatness, while extremity fat measurements were correlated positively and trunk measurements were correlated negatively with the second principal component, which was termed an extremity/trunk ratio component. The two principal components accounted for about 85% of the variance. The first component was related to control variables in order of descending contribution to its variance as follows: sex (21–31%), sport (19%), ethnicity (3%), and age (1–3%). Likewise, the second component (extremity/trunk ratio) was related to the control variables: sex (20–35%), age (4–7%), ethnicity (2%), and sport (2%). Fatness is more influenced by sport and by inference training than is the anatomical distribution or patterning of fat on the extremities relative to the trunk. The latter characteristic may be more dependent on biological or environmental factors unrelated to sport and training.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The purpose of the present study was to investigate the effects of 3-month sprint and endurance training programs on the vastus lateralis muscle fiber area and the activities of glycolytic (phosphofructokinase; PFK) and oxidative (succinate dehydrogenase; SDH) enzymes of adolescent boys. Enzyme activities were also determined after a subsequent 6-month detraining period. Endurance training resulted in significant increases in &OV0312;o2max(58.4 to 64.3 ml·min-1·kg-1), in ST and FTa fiber area (6.0 to 7.3 and 8.0 to 10.4 μm2× 103, respectively), and in SDH activity (6.4 to 9.1 IU). After detraining, &OV0312;O2maxand SDH activity returned to pre-training levels. Sprint training resulted in a significant increase only in PFK activity (28.1 to 33.9 IU), which was also abolished in the detraining period. These data demonstrate that in adolescent boys skeletal muscle enzyme changes are specific to the mode of training and that they are similar in direction but different in magnitude to those found in adults.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The purpose of this study was to quantify the changes in selected intramuscular metabolites associated with non-oxidative energy metabolism after performance of the Wingate Test (WT), a widely used, exhaustive, 30-s cycle test of short-time muscular power. Muscle biopsies were taken from the m. vastus lateralis of nine female physical education students at rest and immediately after performance of the WT. The concentrations of adenosine triphosphate (ATP), creatine phosphate (CP), lactate, and glycogen were determined. The ATP decreased from 20.9 to 13.8; CP decreased from 62.7 to 25.1; lactate increased from 9.0 to 60.5; and glycogen decreased from 360 to 278 (all concentrations are mmol·kg-1dry muscle). The absolute changes in CP and lactate were not as large as those reported in other exercise studies. Based on the metabolite changes, it was concluded that the WT is a satisfactory test of the maximal muscular power that can be generated from non-oxidative metabolism, but that the 30-s duration of the test probably does not tax the maximal capacity of such energy metabolism.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The effects of high intensity, short duration chronic exercise (HSD, N=9) and low intensity, long duration chronic exercise (LLD, N=9) on the selected enzyme activities of three muscles of rats were studied. After 12 wk of treadmill training, the LLD group showed 15–23% decreases in lactate dehydrogenase activity in all muscles (P<0.05), while succinic oxidase activity increased in the soleus (49%) and the vastus lateralis profundus (42%) (P<0.05). No change in creatine kinase activity was found in either group. The HSD group showed no change in lactate dehydrogenase activity; however, phosphofructokinase activity increased (>50%) in both of the fast-twitch muscles (P<0.01), while only the vastus lateralis superficialis showed increased succinic oxidase activity (30–10%) (P<0.05). Following training no difference was observed in mean heart weights; however, the mean body weight of the sedentary control group (SC, N=9) was greater than both exercise groups (P<0.05). No difference was observed between the exercise groups. The mean heart weight/body weight ratios were significantly different between all groups (P<0.01). These results indicated that the HSD group selectively increased its glycolytic power, while the LLD group increased only its oxidative ability. Furthermore, both exercise groups exhibited less gains in body weight than the non-exercise group. This change was independent of any work performed.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID