Effets d'une restriction hydrique et alimentaire prolongée (ramadan) sur la performance et les réponses cardiovasculaires au cours d'un exercice incrémental en milieu tropical chaud

Backgroung

Previous studies showed that maximal oxygen uptake and maximal heart rate were not different during prolonged fasting (ramadan) compared to normal feeding period. However, the effect of ramadan on the blood pressure response during incremental exercise has not been investigated.

Objective

This study aimed to evaluate the evolution of blood pressure during incremental trial in ramadan period.

Methods

Twelve young trained male aged 24 ± 4 yrs participated as voluntary subjects. Their anthropometric parameters, maximal aerobic power and maximal heart were measured in fasting and in normal feeding periods during incremental trial on cycle ergometer.

Results

No significant difference was observed in any anthropometric parameter. Maximal aerobic power of fasting period was significantly less (P < 0,05) compared to normal feeding. Heart rate at rest, at maximal exercise and during a 15 min period of recovery was not significantly affected. Systolic blood pressure of fasting period at maximal power was significantly lower than during the control period (P < 0,05).

Conclusion

Ramadan negatively influences the capacity of maximal power and cardiovascular response at maximal power.     

Analyse de l'électrocardiogramme et de l'échocardiographie de 181 footballeurs professionnels tunisiens

Objectives

The aim of our work was to determine the frequency of various cardiovascular abnormalities and atypical aspects observed in Tunisian competitive athletes.

Material and methods

Our population was constituted of 181 professional football players (average age 23.1 ± 3.9 years) consulted in “Centre National de la Médecine et des Sciences de Sport” of Tunis with to obtain medical certificate authorizing professional football practice.

Results

Electrocardiogram was strictly normal in 67 players (37%). Twenty-nine players had conduction abnormalities. Repolarisation abnormalities were noted in 20 players. Echocardiography was normal in 129 players (71.3%). Ten cases of valvular heart disease were found. The mean left ventricular end-diastolic diameter was 53 ± 4 mm and the mean left ventricular mass was 202.6 ± 42.7 g. The mean relative wall thickness was 0.380. The left ventricular hypertrophy was present in 42 players.

Conclusion

Cardiovascular abnormalities found in electrocardiogram and echocardiography in the Tunisian professional football players are comparable with those usually observed in elite athletes.     

Uchi-komi avec charge,une approche physiologique d'un nouveau test spécifique au judo

Objective

The aim of this study was to elaborate and validate a specific test to evaluate the physical condition of judo players.

Subjects and methods

Twenty-three volunteers, males, aged 22 ± 3.62 years old took part in our experiment. They did the progressive test of Leger et al. (1984), vertical Jump test (Sargent test), Australian shuttle run test and a specific judo test.

Results

The observed results showed significant correlations between muscular power and the number of Uchi-komi on the judo test reference scale (R = 0.52, P < 0.01). Furthermore, there were other correlations between the number of Uchi-komi at the two first sets of specific judo test and the anaerobic power represented by the distance covered in 30s at the Australian shuttle test (R = 0.86, P < 0.01), also between the anaerobic capacity represented by the whole distance covered and the total number of Uchi-komi achieved at the judo test (R = 0.88, P < 0.01).

Conclusion

The test reproduces the physiological characteristics of judo fight. It is a good indicator of the judoka's physical fitness and their cardiovascular adaptation in a physical effort.     

Évolution chez l'homme de l'Insulin-Like Growth Factor-I dans le liquide interstitiel musculaire suite à un exercice en résistance

Introduction

The impact of resistance exercise on the growth of the vastus lateralis was assessed through interstitial microdialysis measurement of free Insulin-like Growth Factor-I at +3 h30, +4 h50 and +6 h after exercise in 4 healthy subjects.

Results

We observed 3 h30 after exercise an interstitial increase in 3 over 4 subjects, and thereafter a progressive decrease. In the mean time, free or total plasma concentrations did not change.

Conclusion

Resistance exercise seemed to induce an early increase of muscle interstitial free Insulin-like Growth Factor-I in order to initiate muscle growth by an autocrine – paracrine way.     

Compression élastique externe et fonction musculaire chez l'homme

Aims

This article reviews the actual knowledge about the use of compression tights and stockings and their effects on muscle haemodynamics during exercise.

Current knowledge

Some questions are still remaining regarding repeated muscular exercise-induced deleterious effects on veins' shears and valves. These effects can be diminished with the use of compression tights or stockings, in order to enhance venous function and improve muscle haemodynamics.

Points of view and plans

The use of compression tights in running activity does not seem to directly enhance the performance per se, but has an effect on muscle function during and after an exercise. This could in part account for a possible decrease in recovery times. Further studies are needed to evaluate the positive effects of these tights during and after an exercise.

Conclusion

Regarding venous function and muscle haemodynamics the use of compression tights is beneficial. However, in order to avoid high pressure deleterious effects, healthy subjects' vascular physiology has to be taken into account when developing compression tights.     

Administration de courte durée de prednisolone et sécrétion d'érythropoïétine

Introduction

The aim of the study is to assess the effects of a short-term therapeutical prednisolone intake on erythropoietin (EPO) secretion.

Synthesis

We studied, according to a double-blind, randomized cross-over protocol, the effects of a 7 day prednisolone intake (60 mg/day) in 10 healthy male subjects on hematocrit, EPO and hemoglobin concentrations. No significant change was found between the treatments (prednisolone/placebo) in the parameters investigated.

Conclusion

In view of the results obtained, short-term therapeutic glucocorticoid intake did not induce any enhancement of erythropoiesis via EPO stimulation that can result in ergogenic advantage during submaximal exercise.     

Effet d'un entraînement en endurance sur les concentrations de l'IGF-1 plasmatique chez le rat

Introduction

The aim of this study was to determine the effects of endurance training on IGF-1, corticosterone and insulin levels in male sedentary and trained rats.

Facts

IGF-1 concentrations decrease after training (p < 0.05), those of corticosterone increase (p < 0.01) whereas insulin levels remain stable.

Conclusion

A short period of endurance training leads to catabolic state with a decrease in IGF-1 concentrations and increase in corticosterone levels.     

Puissance critique de l’enfant prépubère et de l’adulte

Aim

The aim of the study was to compare aerobic and anerobic abilities of prepubertal children and adults with the critical power concept.

Methods

Sixteen children (10.3 ± 0.9 years) and 15 adults (23.5 ± 3.6 years) performed five tests: a maximal-graded test and four constant load exercises until exhaustion. Critical power (CP) and anaerobic-work capacity (CTA) were determined from the power-1/time (P-t) linear relationship.

Results

Determination coefficients for P-t were 0.94 ± 0.05 in children and 0.96 ± 0.04 in adults. PC values were significantly (p < 0.01) lower in children (2.7 ± 0.4 W/kg) than in adults (3.1 ± 0.3 W/kg). CTA values were significantly (p < 0.001) lower in children (136.4 ± 50.8 J/kg) than in adults (247.1 ± 45.7 J/kg).

Conclusion

Satisfying determination coefficients for CP and CTA were found in children and adults. Children have a lower CP and CTA than adults. This result is in accordance with literature.     

Relation entre la puissance et la raideur musculotendineuse chez les sportifs de haut niveau

Goal

The aim of this study was to test the relation between the reactive power and the stiffness of the legs in high trained athletes (sprinters and skiing racers).

Method

A simple method to measure, in field conditions, the leg stiffness during maximal bouncing was used on twenty-eight sprinters, and twenty-nine skiing racers. In addition, the mechanical power called reactive power was calculated according to the method proposed by Bosco. The relationship between stiffness and power was observed in the different groups.

Results

The value of stiffness obtained was 29,866 ± 7372 N.m⁻¹. The power was equal to 52.33 ± 8,72 W.kg⁻¹. The main result of this study was that a relation between stiffness and power was obtained only in the sprinters (r² = 0,68, P < 0,001). This result stressed the influence of the sport speciality on the stiffness control.

Conclusion

The power measured during maximal bouncing, called reactive power is correlated with the leg's stiffness when subjects are trained to produce power in similar conditions. No correlation was obtained in skiing racers. The stiffness measurement was then a complementary test in the physical evaluation of the athletes.     

Reproductibilité test–retest des mesures stabilométriques après reconstruction du ligament croisé antérieur du genou chez le sujet sportif

Objective

To define the 3 day interval test-retest reproducibility of stabilometric measurements in two- and one legged stance in sport subjects recently operated from a knee anterior cruciate ligament reconstruction.

Méthode

Ten subjects aged between 16 to 33 years (23 year ± 5); carried out at 15 days after the knee surgery two sessions to measure steadiness in two legged stance with opened and closed eyes; in one legged stance with opened eyes, in healthy and operated leg, with full knee extension and with 20 degrees knee flexion. The reproducibility was determined using the intraclass correlation coefficient and the standard error of measurement was calculated.

Results

In two legged stance and in one legged stance, knee in 20 degrees flexion, the 95% sway area and the average antero-posterior excursion of the centre of pressure are reproducible (ICC > 0,75).The stabilometric parameters are not reproducible in one legged stance, knee in extension.

Conclusion

The reproducibility of stabilometric parameters is good, in two and in one legged stance knee flexed at 20 degrees, to evaluate the postural progress after anterior cruciate ligament reconstruction.     

Effets d’un exercice de type anaérobie sur le statut antioxydant enzymatique au cours de la récupération chez les judokas

Aim

To evaluate the effect of the anaerobic exercise on the enzymatic antioxidant statute in judokas’ regional level, because the effects of anaerobic exercise on the free radicals and antioxidants are relatively rare and have some divergences.

Materials and methods

We made this study on ten male judokas (age = 18.1 ± 1.6 years; weight = 77.2 ± 11.6 kg; height = 176.4 ± 4.6 cm), which carried out 30 seconds anaerobic capacity test (Wingate test). Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the Wingate test (P0) then five minutes later (P5), 10 minutes later (P10) then 20 minutes later (P20). The measured parameters are: the superoxide dismutase (SOD), the glutathion peroxidase (GPx) and the total antioxidant statute (SAT).

Results

The concentration of the SOD increases significantly (p < 0.05) at (P0); and regains the baseline values at (P20). The concentration of GPx increases significantly (p < 0.05) in (P0); in (P10) GPx reaches the baseline values. No significant effect of the anaerobic exercise was observed on the concentration of the SAT. Positive correlation was observed between the SOD and GPx to p < 0.05.

Conclusion

The anaerobic exercise modifies the activity of the antioxidant enzymes with different kinetics.     

Relation entre le five-jump test, l'épreuve de vitesse sur 30 m et la détente verticale

Aim

To study the relationship between the five-jump test (5JT) performance, 30 m sprint test and vertical jump performances.

Synthesis of facts

Thirteen male soccer players (15–16 years olds) performed the following tests: 5JT, 30 m sprint and 3 vertical jumps: SJ, CMJ and Free CMJ. The 5JT was strongly correlated with 30 m sprint (R = 0.83; P < 0.01), the SJ (R = 0.71; P < 0.01), the CMJ (R = 0.84; P < 0.01) and the free CMJ (R = 0.62; P < 0.05). The 5JT is also correlated with the index of explosiveness (R = 0.93; P < 0.01).

Conclusion

The 5JT can be used to evaluate muscular strength and explosivity of lower limbs in young soccer players.     

30-15 Intermittent Fitness Test et répétition de sprints

Introduction

The maximal running velocity (V_IFT) reached at the end of the 30-15 Intermittent Fitness Tests (30-15_IFT) is very well related to most physiologic determinants of team-sport performance: explosive power of lower limbs, speed, maximal aerobic power and the ability to recover between exercise bouts. Nevertheless, its relationship with repeated sprint ability (RSA) was unknown.

Synthesis of the facts

Present results in 84 team-sport athletes show that V_IFT is very well related to mean sprint time during a RSA test (p > 0.001).

Conclusion

We conclude that V_IFT is highly representative of most physiologic determinants of performance in team-sports, and could thus been used to monitor athletic performance of team-sport players.     

Contrairement à une idée reçue,les femmes n’oxydent pas plus de lipides à l’effort que les hommes,mais leur Lipoxmax survient à une puissance plus élevée

Aims

Several studies have shown that women, when they exercise at a given percentage of their aerobic capacity, oxidize more fat than men, thus saving their protein and glycogen stores. We wanted to characterize these differences in terms of levels of transition of balance of substrate oxidation and maximum lipid oxidation flow rate (MLOFR) during exercise.

Methods

Three groups (61 athletes, 196 sedentary and 47 type 2 diabetes mellitus [T2DM], in whom, men and women were matched for age, BMI and physical activity, performed a sub-maximal exercise test with four 6 min steady state steps for measurement of lipid and carbohydrate oxidation by indirect calorimetry. In all three groups MLOFRs are the same in both sexes (2 to 3 mg min⁻¹ kg⁻¹), but among athletes and sedentary women have a curve of oxidation of lipids shifted to the right, a crossover point of use of substrates (PCX, the power for which energy comes mainly from carbohydrates) occurring at a 10–15% higher percentage of VO_2max (p < 0.01). In DT2 this shift is no longer significant. The point of maximal lipid oxidation (Lipox_max) also occurs at a higher percentage of VO_2max (athletes: 44.27 ± 15.97% theoretical VO_2max versus 31.25 ± 15.66% in men, p < 0.001; sedentary: 50.29 ± 18.66% among women versus 36.75 ± 15.22% in men, p < 0.01; for T2DM these levels (42.8 ± 2.4 to 39.8 ± 3.7%) are not significantly different.

Conclusion

Gender-related differences are found on carefully matched subgroups, but are far to be major. They reflect a right shift by 10 to 15% of the curve of lipid oxidation as a function of VO_2max, while rates of oxidation at the Lipox_max do not differ between genders. In other words, women do not oxidize more lipids at exercise, but their ability to oxidize them reaches a maximum at a higher percentage of VO_2max. This discrepancy seems to disappear in T2DM.     

Técnicas de recanalización vertebrobasilar antes de la introducción de las endoprótesis recuperadoras: la reapertura no es sinónimo de buena evolución

Objectives

To evaluate the recanalization rate and clinical outcome three months after endovascular treatment for vertebrobasilar occlusion before the placement of stentrievers.

Material and methods

We reviewed all cases of basilar thrombosis treated with endovascular techniques at our center. We reviewed the clinical outcomes with the main objective of determining the recanalization rate and the secondary objective of evaluating the outcome using the modified Rankin scale (mRS) three months after treatment. We assessed clinical and angiographic variables and correlated them with outcome and complications.

Results

We reviewed a total of 27 consecutive patients (mean age, 58.1 ± 15.5 y; median National Institutes of Health Stroke Scale (NIHSS), 21, interquartile range, 18-29; median Glasgow coma score (GCS) 7, interquartile range, 4-9.5). The mean time between the onset of symptoms and endovascular treatment was 26.3 ± 41.7 hours. Complete or partial recanalization was achieved in 23 (85.1%) patients. Three months after treatment, 16 (59.2%) had died and 6 (22.2%) had good outcome (mRS ≤ 2).

Conclusion

Endovascular treatment achieved a high rate of recanalization of occlusions of the basilar artery. Nevertheless, a high percentage of the patients did not have a good outcome. New materials might improve the prognosis in these patients.     

Deux mythes concernant l’exercice chez le diabétique de type 1 : le seuil hyperglycémique de 2,5 g/l de contre-indication à l’effort et le glucose pulse

Aims

We addressed the relevance of two usual beliefs about blood glucose response to exercise in insulin-treated diabetic patients. First, that a pre-exercise blood glucose value exceeding 250 mg/dL means that exercise should be avoided because it will result in worsening of hyperglycemia; second, the prediction of carbohydrate oxidation according to the level of exercise “glucose pulse” may have some value to predict how blood glucose levels will respond to exercise.

Methods

Twenty-four type-1 diabetics (12 men and 12 women, age 19–71 years) treated with basal-bolus or continuous insulin delivery by portable pump performed a steady-state exercise on ergocycle at 50% of their predicted P_max (40–200 W) with measurement of blood glucose levels, blood lactate, and exercise calorimetry. This protocol lowers blood glucose (p < 0.05), with a variable magnitude (−4 to −178 mg/dL [mean: −51 ± 9 mg/dL]), i.e., blood glucose decreased in 21 subjects (87.5%). Carbohydrate oxidation rates do not, however, predict the evolution of blood glucose. Baseline blood glucose G₀ (ranging between 89 and 270 mg/dL, i.e., on average 179 ± 14 mg/dL) was in fact negatively correlated (and not positively) to the variation of blood glucose during exercise (r = −0.462; p < 0.05), so that the higher is G₀ the more blood glucose decreases. When G₀ is greater than 250 mg/dL blood glucose decreased on average by −97 ± 26 mg/dL (p < 0.05). During these steady state bouts of exercise, which clearly decrease blood glucose, oxidation of carbohydrates does not predict the decline in blood glucose (minimizing the interest of the concept of “glucose pulse”), and a value of G₀ greater than 250 mg/dL does not predict exercise hyperglycemia so that it is no longer logic to set this value as a threshold for counter indicating exercise.     

Propriétés psychométriques d'un questionnaire de mesure de l'activité physique chez l'enfant scolarisé âgé de six à dix ans : QAPE-semaine

Aims

To elaborate a physical activity questionnaire for school children aged between 6 and 10 years (QAPE-semaine) and to study the psychometric properties (face validity, acceptability, test-retest reproducibility, criterion validity).

Methods

The questionnaire measures physical activities at school, during leisure-time and other activities. Three scores are calculated: variety of physical activities, intensity and sedentary. The questionnaire was pre-tested to study the content validity, and was administered twice to 185 children from two elementary schools. The validity was studied by comparing the results of the questionnaire outcomes with a one day-recall (QAPE-hier) filled out in two occasions (to measure activities during a non school-day and a school-day). The statistic used was the intraclass correlation coefficient (ICC).

Results

The QAPE-semaine was acceptable. The ICC for the reproducibility of variety of physical activities, intensity and sedentary scores were 0.54, 0.47 and 0.68, respectively; and 0.54, 0.56 and 0.64 for the criterion validity of variety of physical activities, intensity and sedentary scores, respectively. All the ICC were significant (P < 0.0001).

Conclusion

The psychometric properties of the QAPE-semaine are satisfactory (moderate to good). Its administration in classes with school professor's help seems however essential.     

Can conventional magnetic resonance imaging predict survival in pediatric diffuse intrinsic pontine glioma? A single institution experience

Background

Pediatric diffuse intrinsic pontine glioma (DIPG) remains dismal regardless the new therapeutic and technical advances.

Objective

To investigate the value of magnetic resonance imaging (MRI) in predicting DIPG prognosis.

Patients and methods

Twenty-five DIPG patients with 95 (initial and post radiotherapy) MR examinations were studied. Hydrocephalus was detected in 6 cases (24%), basilar artery encasement in 20 (80%), ill defined border in 16 (64%), perilesional edema in 2 cases (8%) and none showed leptomeningeal spread. Conformal 3-dimensional radiotherapy (39 Gy/13 fractions or 54 Gy/30 fractions) was applied.

Results

The median overall survival (MOS) was 9.3 months (95% CI: 7.9–10.8) and the one year overall survival was 18 ± 8.9%. Post radiation MRI performed 3–6 months after treatment showed regression in 8 cases (32%), stationary course in 5 (20%) and progression in 12 cases (48%). The MOS was higher in children whose MRI showed regression (10.0, CI: 6.3–13.7) than those with radiological progression (8.0, CI: 5.9–10.1 months) or stationary course (7.0, CI: 4.9–9.1). However; these differences did not rank to the level of significance. There was no statistical association of tumor size (p = 0.907), presence of hemorrhage (p = 0.314), or surrounding edema (p = 0.263); entrapment of the basilar artery (p = 0.782); pattern of enhancement (p = 0.851); and hydrocephalus (p = 0.354) with the length of the overall survival.

Conclusions

Though MRI is the mainstay for the diagnosis of DIPG, yet its prognostic value is limited. New MR techniques as MR spectroscopy and diffusion tensor imaging should be evaluated as additional tools for prognostic evaluation of DIPG.     

Aspects biologiques des interactions de l’exercice et de la récupération

Subject

The use of Fourier transform infrared spectrometry technique (FT-IR) as a pitch technique of the biological control of short and intense exercises close to those of Rugby matches.

Material and method

In reference to 28 rugbymen of international level, the biological results of three short and intense exercises and two periods of recovery were analyzed by TF-IR. The exercises are: (1) sprints; (2) 12 × 20 m of swerve running; (3) 6 × 30 s of shuttle run.

Results

Lactate, glucose, urea, and to a lesser degree, triglycerides showed a significant evolution. If the evolution of the two first was in conformity with the literature, the increase of urea probably results from the activation of the purins–nucleotides cycle, whereas the evolution of triglycerides is explained by their probable muscular use during periods of active recovery. Among proteins related to the healthy sportsman, only haptoglobin presents a significant variation difficult to explain whereas CRP, orosomucoid and immunoglobulins A, G and M remain close to their rest values.

Conclusion

With the use of FT-IR technique, it is possible to intervene directly on the pitches of the sporting practice to control the biological incidences and to adjust the loads individually. It is also possible to detect inflammatory and immunological problems related to the biomechanical and physiological stresses.