Variations de la lactatemie a l'effort et au cours de la recuperation chez des sportifs fumeurs

But : Evaluer l'influence du tabagisme et du niveau de dependance nicotinique sur la variation de la lactatemie pendant l'effort et apres la recuperation chez des sportifs. Materiel et methodes : 126 footballeurs (63 fumeurs et 63 non fumeurs) evoluant dans le championnat d'elite congolais ont ete soumis a un test d'effort rectangulaire et sous maximal; sur un cycloergometre. Des dosages repetes de lactates sanguins ont ete effectues et les variations de la lactatemie durant et apres l'effort ont ete comparees entre les deux groupes; en fonction de la dependance nicotinique. Resultats : nous avons observe une evolution de la lactatemie en deux phases dans les deux groupes ; une phase croissante et une decroissante. La lactatemie etait toutefois plus elevee lors de la phase croissante (p0;001); de meme que la vitesse d'elimination des lactates etait lus lente chez les fumeurs. Le taux des lactates etait directement proportionnel au degre de dependance nicotinique (p0;01). Conclusion : le tabac expose les footballeurs a une hyperlactatemie au cours de l'effort. Cette elevation est proportionnelle au degre de dependance nicotinique. Nos resultats renforcent l'interet des campagnes anti-tabac en milieu sportif dans le but d'ameliorer les performances des facteurs

Valeurs de reference de la puissance anaerobie alactique des bantous congolais de 8 a 20 ans

Evaluer les valeurs de reference de la force explosive et la puissance anaerobie alactique des melano-africains Bantous au cours de la croissance. Methodes : Sept cent quatre vingt (780) eleves negro-africains; bantous Congolais; ages de 8 a 20 ans; dont 390 garcons et 390 filles; ont ete soumis a deux tests de terrain d'evaluation de la force explosive et de la puissance anaerobie alactique des membres inferieurs ; il s'agissait des sauts; horizontal et vertical sans elan. Tous le sujets ne pratiquaient aucune activite physique et sportive de maniere reguliere; a l'exception des cours d'education physique. Pour apprecier le niveau de la croissance staturo-ponderale; les mesures anthropometriques prises. Les valeurs de la puissance anaerobie alactique ont ete exprimees en valeurs absolues (W); puis rapportees au poids corporel (W/kg). Resultats : Les valeurs moyennes de la puissance anaerobie alactique (PAmax) croissent en fonction de l'age civil; et elles sont toujours superieures chez les garcons par rapport aux filles; particulierement a partir de 14 ans (p0001). Par ailleurs la puissance musculaire anaerobie alactique (pAmax) varie en fonction de la longueur des segments corporels et du poids maigre. Nos resultats sont similaires a ceux des autres ethnies humaines. Les differences entre les sexes s'expliquent par la superiorite de la masse musculaire et de la longueur des segments corporels chez les garcons a la puberte; tandis que celles des differentes ethnies humaines sont d'ordre genetique. Conclusion : Nos resultats confirment que les sujets melanodermes ont des caracteristiques musculaires superieures aux autres ethnies humaines; notamment le metabolisme anaerobie alactique

[Recovery from exercise in trained smokers]. / Récupération post-exercice chez le sportif fumeur.

AIM: Assess the influence of tobacco on recovery after exercise in sportsmen. METHODS: Sixty-three smokers aged 18-33 years, practising soccer, participated in this study. These subjects belonged to second division congolese league clubs. Heart rate (HR) was studied during recovery of moderate exercise (Ruffer's test), but also recovery index and arterial pressure. Kinetics of the HR was studied for 7 min for recovery. A control group consisted of 50 non smokers, practising soccer at similar level. RESULTS: Smokers showed heart rate values significantly higher (P < 0.001). Non smokers presented a low recovery index. The recovery has generally two components: the first is slow in smokers, while the second is a fast one. However, recovery rate for the smokers was more rapid during the alactic phase. There exists also differences with regards to smoking tobacco dependence: when compared to great smokers, lower smokers exhibited a faster first phase and a slower second phase. These differences were significant. DISCUSSION AND CONCLUSION: The smokers and non smokers differences are discussed with reference to the effects of nicotinemia and carbon monoxide on sympathetic-parasympathetic balance. Cardiovascular changes during exercise have a twofold control: decrease a vagal tone and increase of sympathetic activity. The comparison of smokers and non smokers concerning recovery led to suppose that there exists a difference in regards of the catecholaminergic sensitivity. The problem of thermoregulation must not be neglected during recovery. As smokers are considered, cutaneous thermolysis is perhaps important when these subjects perform exercise in ambient hot air. Here against, it is known that thermolysis mechanisms are not similar in smokers and non smokers. In conclusion, this study showed that smoking tobacco induce a lower physical condition in sportmen. Recovery rate after exercise may function as a predictor of fitness in smokers.

[Effect of smoking on weight and cardiopulmonary capacities in young athletes]. / Effets du tabagisme sur le poids corporel et les capacités cardiorespiratoires de jeunes sportifs.

The aim of the study was to determine wether smokers practising sports have reduced weight, if recuperation time after moderate exercise and maximal aerobic power were lowered. Thousand young soldiers [50 smokers (S), 50 no smokers (NS)] averaging 24 years in age were studied. The subjects performed to exhaustion on Ruffier test, then a maximal exercise with Cooper test. Several biometrical and physiological parameters were evaluated: weight (W), percent of body fat (PBF), body mass index (BMI), maximal oxygen uptake (VO2 max) and recuperation index (RI). Kinetics of heart rate (HR) were studied for 7 min considering time constant (1 min) and delay for recovery. The smokers showed significant differences for W (p < 0.001), PBF (p < 0.05), VO2 max (p < 0.01) and recuperation index (p < 0.001). Maximal aerobic power were 45.8 +/- 2.7 and 50.3 +/- 3.2 ml/kg/min for S and NS, and RI were 7.5 +/- 0.9 (S) and 5.0 +/- 1 (NS). figure 1 shows that HR recovery of S has generally two components: the first was fast, the second was a slone none. The smokers who presented a great dependence to tobacco smoking had a significant lower RI (p < 0.001) as those subjects with little tobacco dependence (Table 5). The smokers had lower values of VO2 max, and there exists a tobacco dependence difference. Recuperation time for the aerobically well trained S subjects was more rapid during the lactic phase. Note that correlations obtained between the VO2 max and RI were significant (r = - 0.788; p < 0.05). The smokers and no smokers differences are discussed with reference to nicotinemia effects and the sympathetic-parasympathetic unbatance of influences. The comparison of smokers groups concerning cardiovascular data led to suppose that there exists a tobacco dependence difference in regards of the catecholaminergic sensitivity. In conclusion, this study showed that smoker practising a physical activity have a reduced weight, a higher recuperation time and an anaerobic limitation influenced by the state of tobacco dependence.