Un test de terrain simple pour la détermination du seuil anaérobie

Aim – Validate a simple and indirect methodology which supplies a reliable estimate of the run velocity correspondent to the anaerobic threshold.Materials and methods – Twelve subjects took part to this study and each subject was asked to perform a maximum test on 1000, 1500, 2000 and 3000 m. For each athlete was calculate the straight line which joins the values of run tests on 1000 and 1500 and the values on the run tests on 2000 and 3000 m, moreover, the linear regression line interpolating the run values of the 4 tests was calculated. The value of the equation coefficient b of the 2 straight lines and of the regression line was considered the value correspondent to the velocity of the anaerobic threshold. Then each athlete was asked to perform 20 min of continuous run at the 3 various run velocities previously calculated. During the tests previously mentioned the production of haematic lactate was analysed.Results – The 2000 and 3000 m distances are the most suitable to determine the velocity of the anaerobic threshold.     

Augmentation du transport de l’oxygène par le sang : méthodes et stratégies de détection

Aims. – Draw up the inventory of various methods able to increase the oxygen transport by the blood and present methods and strategy of detection.Current knowledge. – Maximal oxygen uptake is the major performance limiting factor in endurance sports. Sophisticated training methods have been developed to increase this variable. On the other hand, attempts have been made to improve maximal oxygen uptake by artificial means: blood doping, administration of human recombinant erythropoietin (rhu-Epo) and, probably, by the use of a new class of therapeutic agents: the artificial oxygen carriers. All these substances and methods are prohibited by the International Olympic Committee. But, until now, the detection of the misuse of these compounds is a problem: there is no detection method for blood doping, the current test method for rhu-Epo can do false negative cases and no screening methods are performed for oxygen carriers.Points of views and plans. – Despite the emergence of the oxygen carriers, in fact easy to detect, the use of r-HuEpo seems the most efficient practice. Today there is a test to detect abuse of r-HuEpo, that’s why the cheats should have recourse to red blood cells transfusion. However concomitant injections of r-HuEpo and GH or IL-3 should use least doses and so to make the detection more difficult. Although indirect methods will be refined, this approach will likely insufficient by itself. A careful definition of an individual’s hematologic profile, the so-called “hematologic passport”, should form the basis for a more successful application of any indirect method and should disturb recourse to doping.     

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.     

Comparaison de deux méthodes d’analyse des variables maximales de vitesse,force et puissance dans l’évaluation fonctionnelle en karaté

Purpose. – The aim of this study was to compare the mechanical variables from 2 different analysis methods during a sprint exercise on cycle ergometer.Methods. – Twenty-two karate practitioners (international and national level) performed 6 sprints of 8 s (friction loads of 0.4; 0.5; 0.6; 0.7; 0.8 and 0.9 N kg^–1). The maximal theoretical values of pedalling velocity and force, the maximal power output and the optimal pedalling velocity were determined from 2 different methods. The friction load method plotted the relationship between the braking force applied on the flywheel and the peak velocity. The SRM method established the relationship between the pedalling velocity and the force applied on the crank — gear from all the 6 friction loads data.Results. – The maximal power output determined from the SRM method was significantly, i) lower (5.2%) compared to the friction load method, ii) higher (16.4%) in the international group compared to the national group. Whatever the method used i) there was no significant difference between groups for the maximal theoretical force ii) the international group showed significantly higher values of maximal theoretical and optimal pedalling velocity.Conclusions. – The results showed no significant effect of the method on the maximal theoretical values of velocity. The SRM method was more sensitive for the measurements of the maximal power output.     

Analyse critique des matériels et des méthodes d’évaluation de l’aptitude physique chez le blessé médullaire en fauteuil roulant

Aims – The aim during rehabilitation of wheelchair users people is to improve their physical capacity that can be quantified in laboratory using specific ergometers and protocols. The propulsion during these tests must be to the nearest of the one daily practice by the subject. Thus, the goal of this brief review is:

• 1.to analyse laboratory device and protocols' characteristics;to define ergometers' and protocols' characteristics the best adapted to an assessment of the physical capacity of this particular population.

Current knowledge – Most existing ergometers and protocols present characteristics and limits that injure the relation between laboratory and field. We looked for wheelchair ergometers’ prerequisite in order to simulate the field to the nearest and that associated tests allows to respect the internal logic of the practice.Points of view and plans – Ergometers’ and protocols’ limits as a whole suggest the development of a new ergometer generation that would allow relations with field. They would be most adapted to wheelchair users’ physical, biomechanical and physiological specificities.     

Effets de l'entraı̂nement sur les potentiels aérobie et anaérobie de jeunes nageurs. Exercice réalisé avec les bras

Aims – Investigate the influence of exercise training on the aerobic and anaerobic capacities of young swimmers.Methods – Ten male swimmers aged 15.2 ± 3.8 years participated: five sprint specialists and five middle-distance specialists. Each subject performed, an arm ergocycle, two laboratory tests, a maximal incremental exercise test and a force–velocity test, once in February (T1) and then again in June (T2).Results – For all subjects combined (n=10), the results showed a significant increase in maximal anaerobic power (p < 0.01) between T1 and T2. Aerobic capacity did not change significantly between the two tests in either group.Conclusion – This study demonstrates the interest of evaluating aerobic and anaerobic capacity in young swimmers during arm exercise. The change in results over the 5-month period between the two tests indicates the importance of scheduling exercise tests during the course of athletic training programs.     

Répercussion de l’asthme induit par l’exercice sur la performance aérobie de l’enfant

Introduction. – Exercise-induced asthma is a clinical syndrome leading to a transient narrowing of the airways after the end of the exercise.Synthesis of results. – In order to observe its effect on aerobic performance 60 prepubescent children including 36 asthmatics have achieved a maximal increased exercise and a 8min constant exercise. The maximal expiratory flow-volume significantly decreased after the 2nd exercise in the exercise-induced asthma children. This means that airways were narrowing with exercise intensity. These narrowing did not seem to have any effect on the aerobic parameters measured in our study.Conclusion. – We conclude that controlled asthma does not limit the aerobic performance in prepubescent children.