Évaluation de l'état de stress oxydatif chez des footballeurs et des basketteurs professionnels

Aim – Evaluation of oxidative stress status.Methods and results – Mean values in antioxidant vitamins, sulphydryl proteins and selenium were found to be in a normal range in the blood of top soccer (n=21) and basketball (n=9) players at the end of half a season of regular training and competititon. Glutathion peroxidase levels were higher than the mean superior value in fourteen players, suggesting a possible adaptation to oxidative stress induced by physical exercise.Conclusion – Despite an apparent normal antioxidant status, the presence of such an oxidative stress is confirmed in half of the players as evidenced by elevated levels in autoantibodies against oxidized lipoproteins.     

Étude des modifications de la balance ortho–parasympathique à l’issue de vols acrobatiques chez des pilotes de voltige aérienne

Objectives – Study was the ortho-parasympathetic balance changes assessment after an aerobatics flight (called push-pull).Conclusion – Post flight fatigue of the autonomic nervous system involved by the “push-pull” accelerations was expressed by changes of the resting ortho-parasympathetic balance.Protocol – Five pilots performed a training flight of 30 minutes with 5 series of 30 seconds of spirals down under negative acceleration (–3 Gz; –4 Gz) followed by 30 seconds of spirals down under positive acceleration (+3 Gz; +4 Gz). Between each series, pilots carried off a flat flight. A stand-test (10 minutes fall flat on the ground, 10 minutes stand up) was realised before flight, 5 minutes after landing, 1 et 2 hours after flight. Electrocardiogram was recorded during the stand-test with an analogical device). Blood pressure was recorded with an automatic monitor.Results – Spectral analysis of resting heart rate variability and blood pressure variability recorded during stand-tests revealed a continuous disturbance of the ortho-parasympathetic balance after flight probably related to the disturbance of the baroreflexe control. Indeed the compared evolutions of heart rate and blood pressure variability before versus after flight showed an increase in sympathetic tone just after flight and an increase in parasympathetic tone during 2 hours after flight.     

Variations des taux d’androgènes et de cortisol au cours de six saisons chez des footballeurs professionnels

Aim. – Compare adrenocortical and testicular functions in professional football players and sedentary age-matched controls using androgens and cortisol determinations.Material and methods. – Sixteen footballers from the Olympique Lyonnais Team and 11 sedentary controls were studied between June 1989 and June 1990. For each subject, eight blood samples were collected during this year for measurement of cortisol, dehydroepiandrosterone sulfate, delta-4-androstenedione and testosterone plasma levels. Furthermore, cortisol determinations were performed in the professional football players of Olympique Lyonnais during five more years, from 1995 to 2000.Results. – The plasma cortisol level was higher in the footballers compared to the controls. Cortisol circannual variations were noted and were the same in the two groups. In contrast, dehydroepiandrosterone sulfate, delta-4-androstenedione and testosterone levels were not statically different in football players and controls. These data indicate no appreciable change in the gonadotropic axis whereas the corticotropic axis was activated in professional footballers. The mechanisms underlying this activation of corticotropic axis were discussed.     

Variations du volume plasmatique induites par un exercice de sprint chez des sprinters,des endurants et des non entraînés de sexe masculin

Aim. – The aim of this study was to investigate the influence of training status (sprint or endurance training) on plasma volume variation (ΔPV) in response to the Wingate-test in male subjects.Method. – We compared the ΔPV between 7 male sprinters (S) (20.9 ± 0.6 years), 7 male untrained (NE) (21.4 ± 0.5 years) and 7 male endurance-trained (E) (20.9 ± 0.8 years) in response to a Wingate-test. Hematocrit and plasma lactate were determined at rest and after 5, 10, 20 and 30 min recovery. The ΔPV was determined by the variation of the hematocrit.Results. – As expected, during the Wingate-test, S developed significantly higher performances than E and NE in absolute and relative values (normalized for body mass or lean body mass). Maximal plasma lactate was significantly greater in S (18.1 ± 1.2 mmol l^–1) than in E (13.4 ± 0.9 mmol l^–1) and in NE (14.2 ± 1.1 mmol l^–1). The Wingate-test was associated with a significant decrease in plasma volume. The mean maximal decrease recorded at the end of the exercise was 18.3, 10.2 and 7.9% respectively in S, E, and NE. The ΔPV decrease was significantly higher in S than E and NE at the end of the exercise and after the fifth minute of recovery.Conclusion. – Thus, this study clearly demonstrated that a brief and supramaximal exercise induced a higher plasma volume decrease in sprinters than in endurance-trained or untrained subjects. The responsible factors of this result remained to be clarified.     

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.     

Évaluation des masses musculaires et des densités osseuses régionales chez des kayakistes de haut niveau

Aim. – To determine the body composition and bone densities in elite teenagers kayak paddlers.Materials and methods. – The population consisted of 14 boys (seven kayak paddlers and seven controls). The training frequency of kayak paddlers was 10 h/week when the control group had less than 4 h/week of physical activity. The body composition and bone density were measured by DXA.Conclusion. – The intensive kayak training seems to improve lean body mass and bone density at the specific sites involved in this activity (arms, trunk).     

Évolution de la lactatémie lors d'une séance de vitesse chez des sprinters de niveau national

Aim – We measured in this work the plasma lactate concentrations in male sprinters competing at national level after repetitions of 50 m sprint at maximal speed on the track.Results – Plasma lactate concentration increases significantly after the first repetition of sprint, from 3.9 ± 0.1 mmol.l⁻¹ before the first sprint to 14.0 ± 3.0 mmol.l⁻¹ observed after the 3th repetition.Discussion and conclusion – Our results confirmed that the activity of the lactic anaerobic metabolism reflected by plasma lactate concentration is very high during the first seconds of sprint exercises below seven seconds. Sprint coaches must take into account these data when they program sprint sessions.     

Effet de la castration sur le développement des muscles squelettiques

Introduction – Study the effects of the castration on skeletal muscle.Synthesis of facts – Physical and chemical muscle characteristics of 90 males, females and males rabbits castrated at three days were studied after slaughter when 14 weeks old. Longissimus dorsi muscle was analysed. LD chemical characteristics were insignificantly modified by castration. LD muscle was significantly more tender for females and castrated males than for entire males.Conclusion – The castration affects internal structure of skeletal muscle of rabbits slaughtered at 14 weeks of age.     

Analyse en laboratoire des performances de certains cardiofréquencemètres

Aim – Testing in precision, facing the same simulator of EKG and by comparison with the system of Holter two heart rate monitors of third generation and a device of the previous one.Methods and results – Two programs of simulation were used: a “steady state” one and an arrhythmic one. Heart rate monitors of third generation progressed distinctly in static precision and were comparable to the Holter in this register. In transient phase it exists always, for heart rate monitors, a smoothing, more marked to the deceleration than to the acceleration. Most, the brief and sudden arrhythmias are not detected or are rejected by the three heart rate monitors. Modifications of EKG tracing can mislead mistakes and a pause of 5 s can't even be discovered.Conclusion – Heart rate monitors are destined therefore to the follow-up of the healthy person, for the pathological ones the use of the Holter imposes itself.     

Prévalence de l'asthme chez l'athlète,influence de la discipline sportive et des conditions environnementales

Purpose – To assess the prevalence of asthma (PA) in competitive athletesMethods – PA was studied in 530 athletes of a regional to an international caliber (cross country-skiers, cyclists, alpine skiers and judokas) on the basis of a specific questionnaire and a reversible airway obstruction.Results – Classified from the lowest to the highest, the PA according to sport was the following : judo, cross-country skiing, alpine skiing, and cycling.Conclusion – These results confirmed the PA is low in athletes who hyperventilate moderatly and are usually sheltered from cold temperatures. Although the PA of skiers (16%) was similar to that reported by other studies the high proportion of allergic asthma (60–80%) suggests a profile different from that reported in this subpopulation by others i.e. non atopic “asthma skiers”. The greater duration of cold exposure in the alpine skier group despite lower ventilatory requirements may account for its greater PA compared to that of the cross-country skiers. Finally, the higher PA of the cyclist group may be explained by the conjunction between the hyperventilation, exposure to aerocontaminants and possibly to cold.