Estimation de la contribution énergétique d'origine aérobie et anaérobie et de sa répartition au cours d'un 800 m couru sur le mode compétition

Aim – Determine the part of each energetic system at different times of 800m competition. Oxygen uptake and speed were recorded continuously.Materials and methods – Five athletes performed on an outdoor track a test to determine the maximal oxygen uptake and the maximal aerobic speed and a supramaximal exercise of 800m.Results – The overall energetic expenditure as well as the oxygen deficit assessed at 31.9% were almost identical at those obtained during an 800m race running on a treadmill. Only the repartition of the oxygen deficit notably differed during the race. This suggered that the kinetic of the speed had a determining incidence on the anaerobic contribution as well as aerobic contribution when there were changes in running velocity.     

Médicaments et performance de la fonction d'équilibration

Introduction – Balance control in some sports discipline can be the aim of the action, and its breaking off can expose to severe trauma.Synthesis of facts – Some drugs' adverse effects can induce lower equilibrium performance, in relation for example with vigilance drop or vestibular ototoxicity. The drug effect site can concern one or more links in the chain (peripheral or central impact). Individual sensitivity is variable, as well as speed of reversibility.Conclusion – Symptoms induced by pathology for which therapy is prescribed are sometimes difficult to distinguish from those induced by therapy itself.     

Overtraining syndrome : la piste de la suractivité ?

Introduction

Overtraining is clearly a multifactorial disturbance. We aimed at evaluating the relative importance of overactivity and nutritional imbalances.

Methods

A comparison of 17 footballers with seven subjects with a diagnosis of overtraining evidenced that the two groups differ by energy expenditure resulting from physical activity (1573 ± 378.6 kcal/d from 804.7 ± 184.7 kcal/d) while food intake does not exhibit significant differences.

Conclusion

In this sample of subjects, inadequate food intake is found in both groups, so that overtraining appears rather characterized by a higher level of physical activity. Therefore, a relative energy deficit resulting from overactivity rather than dietary mistakes appears to explain the syndrome in these athletes, who are thus truly “overtrained”.     

Les bases génétiques et moléculaires de la performance et de l'adaptation à l'exercice physique

Objectives – This paper reviews the state of our knowledge on the genetic and molecular bases of performance and the response to exercise training, the theme of the inaugural conference of the XIXth annual meeting of the Société Française de Médecine du Sport held in Rennes in October 1999.Topics – The studies on the genetic bases of performance performed over the past 20 years suggest that 25 to 50% of interindividual differences observed in maximal and sub-maximal oxygen consumption as well as in other indicators of aerobic performance could be explained by genetic factors. For metabolic and histochemical properties of skeletal muscle, heritabilities ranging from 40 to 70% have been reported. Considerable interindividual differences are also observed in the cardiorespiratory, metabolic and morphologic adaptations to exercise training and results from twin and family studies suggest that these differences are also determined by genetic factors. Unlike many other complex traits such as hypertension or obesity, the search for candidate genes of performance is in its infancy. Only a few studies with candidate genes such as the angiotensin converting enzyme (ACE), the muscle specific creatine kinase (CKMM) or genes of mitochondrial DNA have reported positive results with indicators of aerobic performance.Conclusion – More studies are needed before any conclusion could be made about the role of these genes in performance and adaptation to exercise training. Although the molecular dissection of performance and adaptation to regular exercise is a complex task, considerable progress will probably be achieved in the next decade in our understanding of the molecular basis of these complex phenotypes.     

Dopage et sport : connaissances et attitudes des pharmaciens de la ville de Yaoundé

Introduction – Fourty-one retail pharmacists (23 females and 18 males) out of 70 that Yaoundé town counts, participated to this study aimed at determining their attitudes towards and knowledge in doping. They answered a questionnaire concerning their knowledge of doping agents, how they face doping and the role of pharmacists in doping prevention.Synthesis – Results suggest that pharmacists (54%) have been confronted to doping, less than once a month for 27% of them and at least once a month for the rest. Six pharmacists (15%) have been offered to provide doping agents to sport men. 51% (mainly females) consider that the use of food supplements could induce consumption of forbidden drugs. The majority (83%) of pharmacists (mainly females) consider that doping is a public health problem. They agree (88%) that pharmacists have a part to play in doping prevention but also agree (58%; mainly females) that they are poorly or very poorly informed to that effect.Conclusion – The requests made to pharmacists suggest the consumption of doping agents by sport men in our region. It is therefore necessary to carry out an epidemiologic study on prevalence and consumption patterns.     

Dynamique de la locomotion en fauteuil roulant manuel : influences de la masse totale et de sa répartition antéropostérieure sur la résultante des forces de freinage

Purpose. – This study presents a new method for determining the resultant braking force during wheelchair displacement and investigates the respective effects of the level and the distribution of the system’s mass.Method and results. – A three-dimensional accelerometer was fixed directly under the seat of wheelchair and was used to measure the deceleration of the mass-and-wheelchair’s system. Three masses (50, 70 and 90 kg) were laid on a support in 3 positions corresponding to three distributions (10, 40 and 70%) of the system’s total mass upon the front casters. A series of 15 deceleration trials was performed for each of the 9 combinations. Statistical results showed that the system’s deceleration was mainly explained by the mass distribution upon the front casters (92%) and in the least by the system’s total mass (8%).Conclusion. – Considering the fore-and-aft movements of the subject’s centre of mass during wheelchair locomotion, the results of this study let us assume that the resultant braking force does not remain constant along the propulsion cycle. Moreover, the present method could be used to investigate the influence of wheelchair’s adjustments and floor’s characteristics on the resultant braking force.     

Réponses du cortisol et de la testostérone salivaires au cours de la récupération post-compétitive en rugby

Aim. – In order to evaluate the biological repercussions of the post-competitive tiredness state, we measured the progress of the salivary cortisol and testosterone levels in the players of a rugby-team during the week following an international match.Results. – The results reveal a fall of the cortisol levels during the first 4 days following the competition, compared to the values measured at the same hour of a resting day. Conversely, the testosterone levels present an increase during the same period. Consequently, 5 days of recovery are needed for these two biological variables chosen as tiredness markers to return to their basic values.     

Pharmaciens d'officine et dopage sportif : enquête sur les connaissances et les attitudes au niveau de la région de Dakar au Sénégal

Aim. – Evaluate the knowledge of retail pharmacists of doping in sport and to describe their attitude in front to this phenomenon.Methods. – We proceeded by a prospective self-reported survey by postal mail with 105 retail pharmacists in Dakar which contains 299 pharmacies.Results. – We have received 68 answers. Only 10% of pharmacists know doping definition. They are 66% who think that senegalese sportsmen use doping products. They feel concerned with the problem of doping (81%) and 19% of them said having been contacted during these last 12 months for advice on doping products. They consider that doping is a kind of drug addiction and a public health problem. They estimated to 95% that the most effectiveness means of prevention would be to talk about side effects of doping products with the support of doctors.Conclusion. – This study which has to be extended must bring us to do big preventing actions.     

Effet de la course d’endurance et/ou des isoflavones sur la masse osseuse de la rate castrée

Aim – To study the effects of endurance running (15 m/min during 20 min/day to 28 m/min during 1 h/d, 6 days/week during 12 weeks, corresponding to 62% of the VO₂ max of the animals) or of a treatment by isoflavones (Soylife 100 : 400 μg j^–1 g^–1 of body weight during 12 weeks), either only or cumulated with running, on the osteopenia induced by castration in adult female rat.Results and discussion – Each one of these two treatment has a protective effect of the bone mineral density at the femoral total, diaphysaire and metaphysaire level. But contrary to what had been reported on the cumulated effects of long term endurance running and of a 17β-estradiol treatment 〚3〛, we did not note any additive effect of these two treatments.     

Imagerie de la trachée de l'adulte

Imaging of normal and pathologic trachea at the thoracic and cervical levels is described extensively. Beside congenital abnormalities discovered in adulthood, acquired tracheal abnormalities are artificially divided in two subgroups. One group consists of diffuse abnormalities, with all but one diseases associated with a diffuse narrowing of the tracheal lumen. The other group comprises focal abnormalities that lead to tracheal stenoses of various lengths, with a postintubation stenosis as probably the most frequent cause, followed by tumours. The main modality for tracheal imaging is now multidetector-row spiral CT. This technique allows for faster volume coverage and higher spatial and temporal resolution. The improved spatial resolution impacts on both axial images and all reconstructions techniques that have become indispensable for interpretation of a vertical structure such as the trachea. Chest X-ray is no longer the frontline imaging technique. MRI has not yet reached all its potential as compared to CT.