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Bareket Falk

Publications and source records attributed to Bareket Falk.

13 recordsLinked to original sources
PubMed2006

Effect of low altitude at the Dead Sea on exercise capacity and cardiopulmonary response to exercise in cystic fibrosis patients with moderate to severe lung disease.

Oxygen supplementation may improve exercise tolerance and the physiological response to exercise in cystic fibrosis (CF) patients. Elevated barometric pressure at low altitude is a simple means of increasing the quantity of inspired oxygen. Our objectives were to examine the effect of natural oxygen enrichment (at the Dead Sea, 396 m below sea level) on exercise capacity, and the physiological responses to maximal and submaximal exercise in CF patients. Patients were tested twice: at sea level (barometric pressure, 754 +/- 6 mmHg, mean +/- SD), and at the Dead Sea (barometric pressure, 791 +/- 3 mmHg), in a randomized crossover design. We studied 14 CF patients (6 females, 8 males), aged 15-45 years, with moderate to severe lung disease (mean forced expired volume in 1 sec = 50.0 +/- 11.2% predicted). Tests at each site included resting spirometry, anthropometry, a graded submaximal exercise test, a maximal exercise test on a treadmill, and a 6-min walk test. Tests were performed in identical order at both sites. Tests at the Dead Sea were performed 72 hr after arrival. No differences between sites were observed in lung function at rest. Peak oxygen consumption was significantly improved at the Dead Sea compared with sea level (1.68 +/- 0.73 vs. 1.57 +/- 0.74 l/min, respectively, P = 0.05), along with an improvement in the ventilatory equivalent for oxygen (41.2 +/- 6.3 vs. 46.1 +/- 7.1, respectively, P < 0.05). During submaximal exercise, blood oxygen saturation improved at the Dead Sea compared with sea level at all exercise intensities (P < 0.05). In conclusion, these results suggest that even a brief stay at the Dead Sea area may have physiological benefits for CF patients with moderate to severe lung disease.

Adolescent↗
PubMed2006

Daily physical activity and perception of condition severity among male and female adolescents with congenital heart malformation.

The purpose of this study was to examine among young patients with congenital heart malformation (CHM) the concordance between a cardiologist's definition of the severity of malformation and recommendations regarding physical activity and the patients' perceptions of their condition. Subjects included male (n = 55) and female (n = 45) adolescents aged between 12 and 18 years who have trivial (38%), mild (21%), or moderate (41%) CHM. Thirty-one percent of the patients rated their CHM as less severe whereas 15% rated their CHM as more severe than the cardiologist's definition. Although most patients engaged in physical activity appropriate for their condition, a noteworthy percentage engaged in activities more intense than those recommended by the patient's personal cardiologist.

Adolescent↗
PubMed2006

Child-adult differences in the recovery from high-intensity exercise.

Children recover from physical exertion faster than adults, especially, from high-intensity exercise. It is argued that, qualitatively, this is due mainly to dimensional differences but that, predominantly, it is a quantitative difference, stemming from the lower relative power children can generate and from which they need to recover. Children's lesser power capacity is, in turn, likely due to maturation-dependent neuromotor differences.

Adolescent↗
PubMed2005

Effect of lycopene supplementation on lung function after exercise in young athletes who complain of exercise-induced bronchoconstriction symptoms.

BACKGROUND: It has been suggested that exercise-induced bronchoconstriction may involve oxidative stress. Strenuous exercise promotes free radical production, which can lead to many of the pathophysiologic changes associated with asthma, including bronchoconstriction, mucus secretion, and microvascular leakage. Lycopene has been shown to have high antioxidative activity. OBJECTIVE: To evaluate the effect of lycopene supplementation on airway hyperreactivity and inflammation in young athletes who complain of difficulty in breathing related to physical exertion. METHODS: Nineteen young athletes with exercise-related difficulty in breathing visited the exercise laboratory 3 times. During the first visit, participants underwent a baseline evaluation of exercise-induced bronchoconstriction. Daily for 1 week before each of the 2 subsequent visits, participants ingested 30 mg of lycopene (a natural antioxidant) or placebo (in randomized order, double-blind). A 2-week washout period was given between each visit. During each visit, lung functions were evaluated before and after an 8-minute run on the treadmill (85% of the predicted maximal heart rate). RESULTS: There was no difference in the mean+/-SD decrease in forced expiratory volume in 1 second after exercise during lycopene treatment compared with placebo treatment (11.8%+/-12.5% and 11.0%+/-11.6%). In addition, there was no apparent division into responders and nonresponders. CONCLUSION: A daily dose of lycopene for 1 week does not affect lung function after exercise and may not provide any protective effect against clinical difficulty in breathing in young athletes.

Adolescent↗
PubMed2005

Measurement of talent in team handball: the questionable use of motor and physical tests.

Testing for selection is one of the most important fundamentals in any multistep sport program. In most ball games, coaches assess motor, physical, and technical skills on a regular basis in early stages of talent identification and development. However, selection processes are complex, are often unstructured, and lack clear-cut theory-based knowledge. For example, little is known about the relevance of the testing process to the final selection of the young prospects. The purpose of this study was to identify motor, physical, and skill variables that could provide coaches with relevant information in the selection process of young team handball players. In total, 405 players (12-13 years of age at the beginning of the testing period) were recommended by their coaches to undergo a battery of tests prior to selection to the Junior National Team. This number is the sum of all players participating in the different phases of the program. However, not all of them took part in each testing phase. The battery included physical measurements (height and weight), a 4 x 10-m running test, explosive power tests (medicine ball throw and standing long jump), speed tests (a 20-m sprint from a standing position and a 20-m sprint with a flying start), and a slalom dribbling test. Comparisons between those players eventually selected to the Junior National Team 2-3 years later with those not selected demonstrated that only the skill test served as a good indicator. In all other measurements, a wide overlap could be seen between the results of the selected and nonselected players. It is suggested that future studies investigate the usefulness of tests reflecting more specific physical ability and cognitive characteristics.

Adolescent↗
PubMed2005

Exercise with and without an insulin pump among children and adolescents with type 1 diabetes mellitus.

BACKGROUND: The use of insulin pumps is becoming a popular technique for insulin delivery among patients with type 1 diabetes mellitus (T1DM), but there is no consensus regarding the guidelines for proper pump use during exercise. OBJECTIVE: To investigate the physiologic responses and risk of hypoglycemia among children and adolescents with T1DM when exercising with the pump on (PO) (50% of the basal rate) or pump off (PF). METHODS: Ten subjects with T1DM (6 female subjects and 4 male subjects), 10 to 19 years of age, performed prolonged exercise (40-45 minutes) on a cycle ergometer approximately 2 hours after a standard breakfast and an insulin (Lispro) bolus. Complex carbohydrates (20 g) were provided before and after the exercise. Each patient exercised once with PO and once with PF, in a randomized, crossover (single-blind) manner. During exercise and 45 minutes of recovery, subjects were monitored for cardiorespiratory, metabolic, and hormonal responses. Blood glucose concentrations were recorded for 24 hours after exercise, with a continuous glucose monitoring system, to document late hypoglycemic events. RESULTS: During exercise, blood glucose concentrations decreased by 59 +/- 58 mg/dL (mean +/- SD: 29 +/- 24%) with PF and by 74 +/- 51 mg/dL (35.5 +/- 18%) with PO (not significant). No significant differences were found in cortisol, growth hormone, or noradrenaline levels between PO and PF. There were no differences in cardiorespiratory parameters, blood lactate concentrations, or free fatty acids concentrations between pump modes. Hypoglycemic events during exercise were asymptomatic and occurred for 2 subjects with PO and 2 with PF. Nine subjects had late hypoglycemia after PO, compared with 6 after PF (not significant). CONCLUSIONS: We found no advantage for subjects with either PO or PF during exercise, and we noted that late hypoglycemia was more common than hypoglycemia during exercise. However, PO was associated with a trend of increased risk for late hypoglycemia. We recommend that the pump be removed or turned off during prolonged exercise and that blood glucose concentrations be monitored for several hours after exercise, regardless of the pump mode.

Adolescent↗
PubMed2005

Transient decrease of neutrophil chemotaxis following aerobic exercise.

PURPOSE: Intense exercise affects the immune system, increasing the susceptibility of athletes to viral and bacterial infections. We have previously shown a significant decrease of fMLP-neutrophil migration 24 h after aerobic exercise. In this study we aimed to look at the differential effect of different chemoattractants on neutrophil migration following aerobic exercise, to determine the recovery time, and to better understand the role of the cell skeleton behind the impaired chemotaxis. METHODS: Sixteen female volunteers aged 22-30 yr were tested before, 24, and 48 h after aerobic exercise (30 min running at 70% (.)VO(2max). The submaximal exercise test was conducted a week after the (.)VO(2max) test. We studied the membrane cell receptor response to fMLP, IL-8, and C5a, which have specific ligand-receptor pathways. Further, we studied the cytoskeletal response by investigating the cell polarization and the F-actin polymerization. RESULTS: Significant decrease of the neutrophil net chemotaxis was detected with fMLP, IL-8 and C5a, 24 h after exercise (50 +/- 5%, P = 0.0001; 48 +/- 12%, P = 0.0015; and 32 +/- 11%, P = 0.011, respectively). Complete recovery was observed within 48 h with all chemoattractants. Normal neutrophil random migration and F-actin polymerization were found. Decreased neutrophil polarization was detected (46 +/- 6% vs 22 +/- 8% of polarized cells, before and after effort, respectively; P = 0.004). Correlation between polarization and chemotactic migration was found (r = 0.945; P = 0.001). CONCLUSIONS: The impaired chemotactic response, observed 24 h after exercise, was similar using different chemoattractants. This finding indicates a possible exercise-induced effect on a common factor at the ligand-receptor level. The abnormal cell polarization indicates skeletal dysfunction that should be further investigated and elucidated. The normal fMLP-stimulated-F-actin polymerization reflects an adequate pathway of signal transduction for the formyl peptide.

Adult↗
PubMed2004

Talent identification and early development of elite water-polo players: a 2-year follow-up study.

The processes of talent detection and early development are critical in any sport programme. However, not much is known about the appropriate strategies to be implemented during these processes, and little scientific inquiry has been conducted in this area. The aim of this study was to identify variables of swimming, ball handling and physical ability, as well as game intelligence, which could assist in the selection process of young water-polo players. Twenty-four players aged 14-15 years underwent a battery of tests three times during a 2-year period, before selection to the junior national team. The tests included: freestyle swim for 50, 100, 200 and 400 m, 100-m breast-stroke, 100-m 'butterfly' (with breast-stroke leg motion), 50-m dribbling, throwing at the goal, throw for distance in the water, vertical 'jump' from the water, and evaluation of game intelligence by two coaches. A comparison of those players eventually selected to the team and those not selected demonstrated that, 2 years before selection, selected players were already superior on most of the swim tasks (with the exception of breast-stroke and 50-m freestyle), as well as dribbling and game intelligence. This superiority was maintained throughout the 2 years. Two-way tabulation revealed that, based on baseline scores, the prediction for 67% of the players was in agreement with the final selection to the junior national team. We recommend that fewer swim events be used in the process of selecting young water-polo players, and that greater emphasis should be placed on evaluation of game intelligence.

Achievement↗
PubMed2004

Mechanical efficiency of normal-weight prepubertal boys predisposed to obesity.

PURPOSE: To compare 1) energy expenditure during rest and during submaximal exercise, and 2) the mechanical efficiency of normal-weight boys liable to obesity with normal-weight boys who are not liable to obesity. METHODS: Two groups of prepubertal boys, aged 9-12 yr were compared, one with both parents of normal weight (NP, 20 < or = BMI < or = 27, N = 20) and the other (N = 20) with one obese parent (OP, BMI > or = 30). RESULTS: No significant differences were found between the two groups in the anthropometric measurements (means +/- SD): body mass (32.9 +/- 5.4 and 31.5 +/- 3.1 kg, NP and OP, respectively), stature (141.0 +/- 6.2 and 140.0 +/- 5.5 cm, NP and OP, respectively), and body fat (16.6 +/- 3.5 and 15.1 +/- 3.5%, NP and OP, respectively). Likewise, there were no differences in the reported physical activity habits. No differences were observed in the resting metabolic rate values between the two groups (5.071 +/- 0.351 and 4.956 +/- 0.386 MJ x d(-1) , NP and OP, respectively). Submaximal VO2 at 30, 45, and 60 W was similar in the two groups (0.63 +/- 0.05, 0.78 +/- 0.06, and 0.92 +/- 0.08; and 0.63 +/- 0.06, 0.78 +/- 0.08, and 0.95 +/- 0.08 L x min(-1), NP and OP, respectively). Likewise, the mechanical efficiency, calculated at 30, 45, and 60 W was similar in both groups (19.5 +/- 2.3, 21.8 +/- 2.2, 23.4 +/- 2.5%; and 19.5 +/- 3.0, 21.9 +/- 2.9, 22.6 +/- 2.5%, NP and OP, respectively. No differences were found between groups in their VO2peak (38.4 +/- 3.8 and 40.4 +/- 4.9 mL x kg(-1) x min(-1), NP and OP, respectively). CONCLUSION: These data suggest that energy expenditure during rest and exercise may not be used to predict future obesity in normal-weight prepubertal boys predisposed to obesity.

Age of Onset↗
PubMed2003

Quantitative ultrasound of the tibia and radius in prepubertal and early-pubertal female athletes.

BACKGROUND: Physical exercise during childhood has been shown to enhance bone mineral density, thus reducing the risk of osteoporosis. OBJECTIVE: To examine bone properties, as measured by quantitative ultrasound, in prepubertal and early-pubertal female athletes engaged in impact and nonimpact sports. DESIGN: Survey. SETTING: General community. PARTICIPANTS: Twenty-five acrobatic gymnasts, 21 swimmers, and 21 control subjects. Athletes had been training for at least 1(1/2) years. MAIN OUTCOME MEASURE: Bone speed of sound (bilateral) at the distal radius and the midtibia. RESULTS: Gymnasts were significantly shorter and lighter than swimmers and control girls (P<.001) but had a body mass index similar to that of swimmers. Adiposity was lower in athletes than in controls. Speed of sound did not correlate with measures of body size. Higher mean +/- SD radial speed of sound values (nondominant side) were observed in gymnasts (3764 +/- 104 m/s; P =.045) than in swimmers and control girls (3732 +/- 99 and 3721 +/- 83 m/s, respectively). Mean +/- SD tibial speed of sound values (nondominant side) were similar in gymnasts and swimmers (3629 +/- 87 and 3619 +/- 78 m/s, respectively) and higher in the athletic groups than in the control group (3516 +/- 127 m/s; P<.001). In all 3 groups, no differences were observed between dominant and nondominant sides in the radii or tibias. CONCLUSIONS: Physical exercise, impact and nonimpact, is related to enhanced bone properties, as measured by quantitative ultrasound. Longitudinal studies using various modes of bone evaluation are necessary to determine the long-term effect of various types of exercise on bone properties.

Anthropometry↗
PubMed2003

Resistance training, skeletal muscle and growth.

Resistance training in youth and its effectiveness, possible effect on growth and safety considerations, has received considerable public and scientific attention in recent years. Although few early studies questioned the usefulness of resistance training in children, numerous recent studies have demonstrated its effectiveness in both children and adolescents. Nevertheless, the optimal intensity and volume of training for youths of different ages requires further study. The increase in strength following resistance training in youths, especially in prepubertal children, is believed to be due mainly to neural adaptations and only minimally, if at all, to muscle hypertrophy. Few studies have examined the long-term effect of resistance training on growth. The few which have, found that, contrary to the common misconception that resistance training may retard growth. Scientific evidence indicates that resistance training results in increased serum IGF-I and that there is no detrimental effect on linear growth. Finally, numerous studies have demonstrated that with appropriate supervision and precautions, resistance training can be safe and effective for children and adolescents.

Adolescent↗
PubMed2002

Weight gain associated with increased food intake and low habitual activity levels in male adolescent schizophrenic inpatients treated with olanzapine.

OBJECTIVE: The authors studied weight gain mechanisms and energy balance in patients treated with olanzapine. METHOD: The body mass index of male schizophrenic adolescent inpatients treated with olanzapine (N=10) and of 10 matched patients treated with haloperidol (N=10) were measured at baseline and after 4 weeks of treatment. For the patients treated with olanzapine, caloric intake, resting energy expenditure, and physical activity (determined through accelerometry and heart rate monitoring) were assessed at baseline and after 4 weeks of treatment. RESULTS: Body mass index significantly increased in those treated with olanzapine but not in those given haloperidol. The increase in body mass index was due to an increase in caloric intake without change in diet composition. Olanzapine had no significant effect on resting energy expenditure. Daily energy expenditure was very low before and after treatment. CONCLUSIONS: Olanzapine-induced weight gain is associated with a general increase in caloric intake.

Adolescent↗