Elio Volta

Specifically designed physical exercise programs improve children's motor abilities

Physical activity in schools is declining in many countries and inactivity in childhood has become a recognized risk factor. Data from a program of professionally guided physical exercise in primary school children were collected before and after the academic year of training. Four thousand five hundred children (6–10 years) were enrolled, and conditional and coordinative motor abilities (speed, trunk flexibility, long jumping, somersault, Harre circuit test) were measured. Anthropometric measurements were focused on body mass index (BMI), weight and height. Females never showed a significant variation of BMI, whereas males in the first and fourth grades showed significant differences. On the contrary, when considering the motor abilities studied, all the comparisons were highly significant. At the end of training, both males and females did better than at the beginning, and males were constantly faster than females. Our data, generated on a large number of children, show that professionally guided programs of physical education in the primary school lead to significant progresses in the development of conditional and coordinative abilities, without altering BMI values, thus not interfering with the balanced progression of body weight and height.

Naloxone decreases the inhibitory effect of alprazolam on the release of adrenocorticotropin/cortisol induced by physical exercise in man

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Alprazolam (ALP), a benzodiazepine activating GABAergic receptors, is involved in ACTH secretion. WHAT THIS STUDY ADDS • This study demonstrates a partial opioid influence in the inhibitory effect of ALP on the release of ACTH/cortisol during physical exercise. AIMS To establish the possible involvement of alprazolam (ALP) and/or opiates in the mechanism underlying the ACTH/cortisol response to physical exercise. METHODS Tests were carried out under basal conditions (exercise control test), exercise plus ALP (50 µg at time -90 min), naloxone (10 mg at time 0) or ALP plus naloxone. Plasma ACTH and serum cortisol concentrations were evaluated in blood samples taken before, during and after the bicycle ergometer tests. RESULTS ACTH and cortisol concentrations rose significantly after physical exercise. Maximum peak at time 15 min (P ≤ 0.01 vs. baseline) for ACTH and at time 30 min (P ≤ 0.01 vs. baseline) for cortisol. In the presence of naloxone, the ACTH and cortisol responses were significantly increased (maximum peak at time 20 min, P ≤ 0.02 vs. control test for ACTH, and at time 30 min (P ≤ 0.01 vs. baseline) for cortisol) whereas they were abolished by ALP. When ALP and naloxone were given together, the inhibitory effect of ALP was partial. CONCLUSIONS These data demonstrate an inhibitory effect of ALP in the regulation of the ACTH/cortisol response to physical exercise in man and suggest that GABAergic receptor activating benzodiazepines and opioids interact in the neuroendocrine secretion of ACTH/cortisol.

Effect of physical training on age-related reduction of GH secretion during exercise in normally cycling women

OBJECTIVE To evaluate whether prolonged physical activity (25 km/week running for 8 years) modifies GH decline. DESIGN The GH response to maximal exercise on bicycle-ergometer was tested in younger (26-30 years) and older (42-46 years) healthy women. Each age group included 2 subgroups of 10 sedentary and 10 runners, which were compared. The workload was increased at 3 min intervals from time 0 until exhaustion. Subjects with a low maximal capacity (as established in a preliminary test) pedalled for 3-4 min against no workload at the beginning of the test, so that exercises lasted about 15 min in all individuals. RESULTS At exhaustion, heart rate and systolic pressure were significantly higher in sedentary than in trained subjects, whereas V(O(2)max), blood glucose and plasma lactate levels were similar in all groups. Exercise induced similar GH responses in younger sedentary and exercise-trained subjects and in older exercise-trained subjects, with mean peak levels 7.5 times higher than baseline. In contrast, in older sedentary women peak GH level was only 4.4 times higher than baseline and was significantly lower than in the other groups. CONCLUSION These data suggest that in women prolonged physical training exerts protective effects against age-dependent decline in GH secretion.

Effect of serotonergic system on AVP secretion induced by physical exercise

The present study was undertaken in order to establish the possible involvement of serotonergic receptors in the control of physical exercise-stimulated vasopressin secretion. Twenty-one healthy men (divided in three groups of seven) underwent bicycle-ergometer tests until exhaustion: exercise control test (n=21), exercise plus ondansetron, selective 5-HT3 antagonist (n=7), exercise plus buspirone, selective 5-HT1A receptor agonist (n=7), exercise plus sumatriptan, selective 5-HT1D receptor agonist (n=7). AVP levels, physiological and biochemical variables were measured and compared during tests. Results showed that exercise-induced AVP rise did not change after the administration of buspirone and sumatriptan. In contrast, the administration of ondansetron significantly reduced physical exercise-induced AVP rise. Mean peak levels during physical exercise were 4.9 times higher than basal values in the control test and 2.6 times higher than basal values in the ondansetron plus exercise test. These data demonstrate that 5-HT3 serotonergic receptors at least partially mediate the AVP response to physical exercise. On the other hand, 5-HT1A and 5-HT1D serotonergic receptors do not appear to be involved in the control of AVP secretion during exercise.

Effect of naloxone on somatostatin inhibition of arginine vasopressin response to physical exercise in normal men

To establish whether somatostatin (SRIH) and/or endogenous opioids play a role in the control of arginine–vasopressin (AVP) response to physical exercise, eight healthy men underwent four bicycle–ergometer tests until exhaustion: exercise control test; exercise plus SRIH, naloxone or SRIH plus naloxone. Serum AVP levels, physiological and biochemical variables were measured during tests. Physiological and biochemical variables were similar in all tests. During control test exercise significantly increased serum AVP levels, with a peak value 4.1 times higher than baseline. The AVP response to exercise was similar in the presence of naloxone, whereas it was significantly reduced by SRIH (AVP peak was only 2.8 times higher than baseline). When SRIH and naloxone were given together, the exercise-induced AVP rise was comparable to that observed in the control test. Results indicate a somatostatinergic involvement in the regulation of the AVP response to physical exercise. Furthermore, naloxone-sensitive endogenous opioids appear to play a role in the mechanism underlying SRIH inhibitory action, but not in mediation of the AVP response to physical exercise.

Weight Status Is Related with Gender and Sleep Duration but Not with Dietary Habits and Physical Activity in Primary School Italian Children

The prevalence of overweight and obesity in children has risen greatly worldwide. Diet and poor physical activity are the two risk factors usually examined, but epidemiological evidence exists suggesting a link between sleep duration and overweight/obesity in children. The aim of this study was to describe the relationship among body mass index (BMI), diet quality, physical activity level, and sleep duration in 690 children attending the 5th grade in primary schools (9–11 years old) in the city of Parma (Italy) involved in the Giocampus educational program. This was achieved through (i) measuring anthropometric data to compute body mass index; (ii) administering a food questionnaire to evaluate adherence to the Mediterranean Diet (KIDMED score); and (iii) administering a lifestyle questionnaire to classify children physical activity level (PAL), sleep duration, and school achievement. A highly significant negative association was found between BMI and sleep hours. Moreover, there was a significant positive association between PAL and KIDMED scores. No evidence was found of association between BMI and PAL, nor between BMI and KIDMED score. Data from this study established that BMI is correlated to gender and sleep duration, defining sleep habits as one of the factors linked to overweight and obesity.

Effect of naloxone on the inhibitory effect of melatonin on the release of arginine-vasopressin induced by physical exercise in man.

This study was performed in order to establish whether endogenous opioids play a role in the inhibitory effect of melatonin on arginine-vasopressin (AVP) response to physical exercise. Seven healthy men underwent four bicycle ergometer tests until exhaustion [exercise control test, exercise plus naloxone (2mg injected plus 5mg infused intravenously), exercise plus melatonin (6mg), exercise plus melatonin plus naloxone]. Plasma AVP concentrations, non endocrine physiological parameters (NEPP) and biochemical parameters were evaluated during all tests. NEPP and biochemical values had a similar pattern during all tests. Physical exercise significantly increased the AVP levels. The pre-treatment with melatonin inhibited the AVP response to physical exercise. In contrast, naloxone had no effect on AVP rise during exercise, when given alone, whereas it abolished the negative effect of melatonin on AVP response to physical exercise. Our data indicate that naloxone-sensitive endogenous opiates mediate the inhibitory modulation exerted by melatonin on the AVP response to physical exercise.

Anthropometric outcomes associated with a primary school-based health promotion programme in the Italian city of Parma

The City Council of Parma and allied partners launched a programme based on professionally guided physical exercise and nutritional education in all primary schools of the metropolitan area, with a total of 7,000 children involved, ranging from 6 to 10 years of age. One scientific end-point of the programme was the definition of the parameter(s) most associated with increased physical activity and potential modification of eating habits. To this purpose we studied in a cohort of 2,151 9-year-old children the associations among BMI, fat mass (FM), breakfast eating and the amount of physical activity, the most relevant variables that characterize lifestyle. There was a consistent significant inverse correlation between FM and physical activity and a significant correlation between FM and breakfast skipping. When sorted by BMI, an inverse significant correlation was found between FM and physical activity in boys, except in those underweight. In girls, a significant correlation was found in those of normal weight, but not in those overweight or obese. The number of sports practised was related to FM only in overweight and obese boys. Breakfast skipping was significantly correlated with FM only in underweight girls. Taken together, our data show that FM can be used to accurately evaluate physical activity and eating habits in children, and suggest that, in preventive health programmes, the fundamental parameter to pay attention to is the amount rather than the type of physical activity.

Inhibitory Effect of Dexamethasone on Arginine-Vasopressin Release Induced by Physical Exercise in Man

To establish whether glucocorticoids inhibit the arginine-vasopressin (AVP) response to physical exercise, 10 healthy men underwent bicycle ergometer tests until exhaustion (exercise control test, exercise plus dexamethasone [2 or 4 mg in an intravenous bolus]). Physiological and biochemical variables were similar in all tests. Pretreatment with dexamethasone (2 or 4 mg) partially but significantly decreased the AVP response induced by physical exercise. Our results demonstrate a partial inhibition induced by glucocorticoids of AVP neurosecretion during cycle ergometer tests.

Joint mobility/muscular chain elasticity and motor coordination in a cohort of 9-11 years school children exposed to specifically designed and professionally guided training

Beside the positive role that an active lifestyle plays in the physical and emotional well-being of a child, physically active children have lower risks to encounter injury as adults. However, many groups have reported that only a small population of children in western countries are sufficiently active (1, 2). The aim of this study was to investigate whether joint mobility/muscular elasticity and coordination were related to a merely active lifestyle or could be significantly improved in the presence of a collective, easy-to-perform, but specifically-designed and professionally-guided school program. Specific functional and anthropometric parameters were single-blind tested on 277 children (aged 9-11 years). 148 were randomly assigned to a school-based physical education program specifically designed to increase coordination and elasticity and supervised by professionals, while 129 (control group) continued their usual physical activity at school, with no specific program. The specific program generated a significant improvement of joint mobility and coordination abilities as compared to non-specific physical activity. As a secondary end-point, gender and BMI-related differences emerged during the study, showing that females respond better to a low intensity program, while males benefit of a higher intensity (or a differently designed) program, particularly when belonging to overweight/ obese BMI classes. These results, building up on those from our and other groups, should orient decision-makers in the area of physical exercise for primary school children in favour of specifically designed programs based on demographic and anthropometric data.