Combined effects of caloric restriction and branched-chain amino acid supplementation on body composition and exercise performance in elite wrestlers.

Twenty-five competitive wrestlers restricted their caloric intake (28 kcal.kg-1.day-1) for 19 days, using a hypocaloric control (hC, n = 6), hypocaloric high-protein (hHP, n = 7), hypocaloric high-branched-chain amino acid (hBCAA, n = 6), hypocaloric low-protein (hLP, n = 6) diet to determine the effects of caloric restriction on body composition and performances versus control diet (C, n = 6). Anthropometric parameters (weight, percent body fat) and adipose tissue (AT) distribution measured by magnetic resonance imaging (MRI) obtained before and after diet, were compared. A significant highest body weight loss (-4 kg, p < 0.05) and decrease in the percent of body fat (-17.3%, p < 0.05) were observed for subjects of the hBCAA group. Subjects of the hBCAA group exhibited a significant reduction (-34.4%, p < 0.05) in abdominal visceral adipose tissue (VAT). There was no change in aerobic (VO2max) (p > 0.75) and anaerobic capacities (Wingate test) (p > 0.81), and in muscular strength (p > 0.82). We conclude that under our experimental conditions, the combination of moderate energy restriction and BCAA supplementation induced significant and preferential losses of VAT, and allowed maintainance of a high level of performance.

Branched-chain amino acid supplementation during repeated prolonged skiing exercises at altitude.

This study was conducted to test the hypothesis that a branched-chain amino acid (BCAA) supplementation would minimize changes in body composition and alterations in plasma amino acid profile induced by prolonged exercises at altitude. Twenty-four highly trained subjects participated in six successive sessions of ski mountaineering (6-8 hr duration, altitude 2,500-4,100 m). Twelve subjects took a dietary supplement of BCAA (BCAA group) and 12 took a dietary supplement that was 98% carbohydrate (C group). Body weight decreased in C subjects (-2.1%, p < .01), while the body weight loss recorded in the BCAA group was not statistically significant (-1.2%, NS). Changes in body composition that resulted from repeated skiing exercise at altitude were not significantly minimized by BCAA administration. Peak power output recorded during an incremental bicycle exercise decreased in C subjects but did not change significantly in BCAA subjects. Results of this study demonstrate that neither changes in body composition related to the ski mountaineering program nor muscular performance during isometric contraction was significantly affected by BCAA administration.

Physical performance and metabolic changes induced by combined prolonged exercise and different energy intakes in humans.

The purpose of this study was to evaluate the effects on physical performance of three levels of energy intake during a 5-day period of prolonged physical exercise and relative sleep deprivation. A group of 27 male soldiers were randomly assigned to three groups receiving either 1800 kcal.24 h-1 (7560 kJ, LC), 3200 kcal.24 h-1 (13440 kJ, MC) or 4200 kcal.24 h-1 (17,640 kJ, HC). They took part in a 5-day combat course (CC) of heavy and continuous physical activities, with less than 4 h sleep per day. Performance capacity was tested just before and at the end of CC. Maximal oxygen uptake (VO2max) was determined during an exhausting incremental exercise test on a cycle ergometer. Anaerobic performance was measured from the time during which exercise could be maintained at supra maximal loads on a cycle ergometer. After CC, the subjects receiving LC exhibited a 14% decrease in power output at exhaustion in the incremental exercise test [from 325 (SEM 8) to 278 (SEM 9) W, P < 0.001] and a significant decrease in VO2max of 8% [from 3.74 (SEM 0.06) to 3.45 (SEM 0.05) 1.min-1, P < 0.05]. The remaining two experimental groups demonstrated the same mechanical and metabolic performances on days 1 and 5. Anaerobic performance was not influenced by energy intake and the field course. Blood samples were obtained at rest on days 1 and 5. At the end of CC, the data demonstrated a significant decrease in blood glucose concentrated ion (P < 0.01) for LC diet only.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluid shifts and endocrine responses during lower body negative pressure and dynamic arm exercise.

The use of lower body negative pressure (LBNP) is proposed as a means of reducing the effect of spaceflight on body water loss by stimulation of renin angiotensin aldosterone system (RAAS) activity. Seven subjects were successively submitted to LBNP exposure, arm cranking physical exercise, and to a combination of both procedures (LBNP + arm cranking) in order to check whether this combination enhances RAAS activity. The results showed that exposure to 40 min of LBNP to a level of -40 mm Hg was a more potent stimulus for renin secretion than submaximal and maximal arm cranking. The combination of LBNP with exercise does not further enhance the RAAS activity induced by LBNP alone. These data suggest that the fluid shift toward the lower body induced by LBNP counteracts triggering of renin secretion due to physical exercise.

Antepartum fetal heart rate monitoring. A semi-quantitative evaluation of the 'non-stressed' fetal heart rate.

1964 recordings (from 246 patients were analysed on the basis of a semi-quantitative evaluation of base-line heart rate variability. All the tracings were obtained in the antepartum period, between the 20th wk of pregnancy and prior to the onset of labour. None of the recordings were made during labour or after induction of uterine activity so that a 'non-stressed' fetal heart rate test was obtained in every case. The percentage of flat tracing in each recording and the presence of sinusoidal patterns were compared with the neonatal outcome. When the tracings included a more than 50% flat pattern, 81.8% of the babies were distressed at birth. When a less than 50% flat recording was present only 11.4% of the neonates were distressed. Sinusoidal patterns were more frequently associated with abnormal tracings including those with more than 50% flat recordings. The presence of sinusoidal features did not significantly influence the neonatal outcome for tracings with a less than 50% anomaly: conversely sinusoidal patterns superimposed on a more than 50% flat tracing were predictive of fetal compromise and neonatal distress in 100% of the cases. These results allow to advocate the use of 'non-stressed' antepartum fetal heart rate monitoring, as a reliable test in the management of high risk pregnancies.

Antepartum fetal heart rate monitoring. II. Deceleration patterns.

Fetal heart rate was studied during the antepartum period in 246 patients, yielding a total of 1964 recordings. The following parameters were evaluated and correlated: --the semi-quantitative assessment of fetal heart rate instability (as expressed by the percentage of duration of flat traces); --the presence of decelerations and their relationship to the presence or absence of uterine contractions; --the neonatal condition. Overall, 50% of the patients exhibited uterine contractions while 30% contained decelerations patterns either occurring spontaneously or in association with uterine contractions. A definite relationship was observed between the presence of severe decelerations (irrespective of the time relationship with any uterine contraction) and poor neonatal outcome. A relationship does exist between the presence of severe decelerations and flattening in the recording, which, as demonstrated in the previous part of the paper also exhibited a strong positive relationship with the neonatal outcome. When one considers the different degrees of flattening, it appears that a further correlation between decelerations and neonatal state is demonstrable only in the case of a 10--50% flat recording. Here the probability of a distressed baby is 20% in the absence of decelerations, but 43.4% in the presence of decelerations. In other cases (i.e., less than a 10% or more than a 50% flat recording) the pronostic significance of the instability of the record is not significantly modified by he presence or absence of decelerations. These results indicate that consideration of decelerations is only advisable in these cases where instability is moderately affected (flattening in 10-50% of the record) and that the use of the oxytocin challenge test OCT may be reserved for such cases, when these are neither spontaneous contractions nor decelerations and not contraindications present.

Antepartum fetal heart rate monitoring. III. Fetal movements and accelerations in fetal heart rate.

This third part of the paper deals with the study of the relationships between fetal movements, fetal heart rate accelerations associated with such movements, fetal heart rate instability and neonatal outcome. No correlations has been found between absence of fetal movements and neonatal distress. A correlation has been found between the lack of fetal heart rate accelerations, the flatness of the record and poor neonatal outcome. In extreme situations (i.e. flatness in less than 10% of the record or in more than 80%) the presence or absence of accelerations does not add further useful information. Such information, however, is gained in the intermediary situations (the 'combined' recordings) and particularly when the record is between 51 and 80% flat where there appears to be an 85.6% risk to the fetus. Consequently, when trying to analyse an antenatal record it seems advisable to take primarily into account the percentage of flat recordings (providing the records are numerous enough and of sufficient length). Then, in records between 10 and 50% flat, the presence or the lack of spontaneous decelerations requires consideration whereas, when the record is between 51 and 80% flat, it is the presence or absence of fetal heart rate accelerations which is important.

Nonstressed fetal heart rate monitoring in the antepartum period.

The role of nonstressed monitoring of the fetal heart rate (HR) in determining fetal well-being during the antepartum period was assessed in 125 high-risk patients. Observations on HR, variability, and HR response to fetal movement (FM) and uterine contractions (UC) over a 30 minute period were made with an external microphone and tocotransducer. A total of 625 tests were performed; the earliest gestation tested was 28 weeks, and the latest was 46 weeks. A reactive pattern (variability greater than 6 b.p.m. and accelerations with FM) appears to be a reliable indicator of fetal well-being. All the 51 fetuses exhibiting this pattern survived. This group also had the lowest incidence of neonatal complications. On the other hand, of the babies who failed to show variability greater than 6 b.p.m. or accelerations with FM (nonreactive pattern), 40% died in the perinatal period. Thirty-five patients showed features of both a reactive and nonreactive pattern (combined pattern). Poor outcome in this group was confined to those in whom the majority of the pattern was nonreactive. An undulating HR pattern with virtually absent variability (sinusoidal pattern) was found in 20 Rh-sensitized fetuses, 50% of whom died in the perinatal period. Bradycardia and tachycardia were not found to be reliable signs of fetal distress antepartum. Of the 12 fetuses who died during observation, six showed late decelerations with spontaneous UC but all showed diminished variability. The close correlation between nonstressed patterns and neonatal outcome demonstrated by this preliminary study warrants further use of this technique for fetal evaluation.

Hydrological and Ecological Problems of Karst Regions: Hydrological actions on limestone regions cause distinctive ecological problems.

Climate exerts a universal dominant influence on ecology, but processes of karstification have an equally high ecological influence in carbonate rock regions. Development of karst features depends greatly on the degree to which water containing carbon dioxide has been able to move on and through carbonate rocks and to remove some of the rock in solution. Distinctive features of many karst terranes include scarcity of soils, scarcity of surface streams, and rugged topography; less distinctive are the highly permeable and cavernous rocks, especially at the shallow depths. This high permeability gives rise to many practical problems, including (i) scarcity and poor predictability of groundwater supplies, (ii) scarcity of surface streams, (iii) instability of the ground, (iv) leakage of surface reservoirs, and (v) an unreliable waste-disposal environment. Natural karst processes in some carbonate rock regions have caused a greater restriction in the development of biota than man can ever be suspected of causing.