Paraplegics have low aerobic capacity because of the spinal cord injury. Their functional muscle mass is reduced and usually untrained. They have to use upperbody muscles for displacements and daily activities. Sympathic nervous system injury is responsible of vasomotricity disturbances in leg vessels and possible abdominal vessels, proportionally to level injury. If cord injury level is higher than T5, then sympathic cardiac efferences may be damaged. Underbody muscles atrophy and vasomotricity disturbances contribute to phlebostasis. This stasis may decrease venous return, preload and stroke volume (Starling). To maintain appropriate cardiac output, tachycardia is necessary, especially during exercise. Low stroke volume, all the more since it is associated with cardio-acceleration disturbances, may reduce cardiac output reserve, and so constitutes a limiting factor for adaptation to exercise. The aim of this study was to verify if use of an underlesional pressure suit may increase cardiac output reserve because of lower venous stasis, and increase performance. We studied 10 able-bodied and 14 traumatic paraplegic subjects. Able-bodied subjects were 37 +/- 6 years old, wellbeing, not especially trained with upperbody muscles: there were 2 women and 8 men. Paraplegics were 27 +/- 7 years old, wellbeing except paraplegia, five of them practiced sport regularly (athletism or basket for disabled), and the others just daily propelled their wheelchair; there were 5 women and 9 men. For 8 of them, cord injury levels were located below T7, between T1 and T6 for the others. The age disability varied from 6 months to 2 years for 9 of them, it was approximately five years for 4 of them, and 20 years for one. We used a maximal triangular arm crank exercise with an electro-magnetic ergocycle Gauthier frame. After five minutes warm up, it was proceeded in one minute successive stages until maximal oxygen consumption is raised. VO2, VCO2, RER were measured by direct method with an Ergostar analyser every 30 seconds. Heart rate was registered continuously using a cardio-frequence-meter Baumann, and ECG was observed on a Cardiovit electro-cardiograph. Each subject reached maximal exercises on different days: one without any contention, and the other one with abdomen and legs contention using an antigravity suit, inflated to 45-50 mm Hg for legs and 30-40 mm Hg for abdomen. The able-bodied subjects VO2 peak was 24 +/- 5.8 mL min-1 kg-1, without any change on peak VO2 and on cardiac frequency when pressure suit was used. Results were different for paraplegics: peak VO2 was significantly higher (21.5 +/- 6.5 mL min-1 kg-1 without contention and 23.8 +/- 6.3 mL min-1 kg-1 with contention), heart rate was significantly lower at all stages of exercise with antigravity suit and comfort was better during exercise and rest. In our study, contention contributed to increase paraplegics's performances, but responses depend also on spinal cord level, injury age, spasticity. Therefore, testing paraplegics using an antigravity suit may be useful to determine if neurovegetative disturbances significantly modify their cardiac adaptation and capability. If gravity suit is efficient, contention tights might be prescribed, with respect to subject's legs measurements. But, because these tights are very difficult to put on, their efficiency has to be proved before, the motivation of the subject is essential too.
Une enquête épidémiologique et thérapeutique de 18 mois a été effectuée sur 889 sportifs examinés au Centre régional de médecine du sport de Limoges (Haute-Vienne). Ce travail avait pour but d'évaluer l'importance des affections fongiques cutanées en milieu sportif, afin de définir un ensemble de mesures préventives. Une étude biologique a permis d'identifier les espèces fongiques responsables des mycoses. Globalement, 559 sportifs sur 889 observés sont porteurs de mycoses cutanées, soit 62,8%. Ces résultats correspondent sensiblement à ceux de la littérature. Quatre espèces fongiques ont été isolées: Trichophyton rubrum, Trichophyton interdigitale, Epidermophyton floccosum, Scopulariopsis brevicaulis. Elles figurent parmi les agents anthropophiles les plus fréquemment pathogènes pour l'homme. Les relations qui existent entre la nature du sport pratiqué et la localisation anatomique des lésions ne sont pas simples: les sports collectifs, où les individus échangent facilement leurs vêtements, et ceux où les causes de macération sont fréquentes, constituent les foyers principaux de mycoses cutanées. Il apparaît indispensable de dépister systématiquement les affections fongiques cutanées, de manière à les traiter efficacement et d'y associer un traitement antifongique des sols des locaux sportifs. Seul un schéma préventif intégré peut faire diminuer significativement l'incidence des mycoses cutanées.
Cet article fait un tour d'horizon des questionnaires d'activité physique les plus utilisés dans la littérature anglo-saxonne. Parmi les nombreuses méthodes de mesure et d'évaluation de l'activité physique, le questionnaire est la plus pratique et la plus utilisée dans le cadre des études épidémiologiques portant sur de vastes échantillons de population. Aux fins de la présente étude, les questionnaires se subdivisent en quatre grandes catégories: le journal, le rappel d'activités physiques à court terme, les antécédents d'activités et le questionnaire d'ordre général. Chacun de ces questionnaires étant en quelque sorte spécialisé, le chercheur peut donc choisir celui qui, parmi un large éventail, sera le mieux adapté à la composante d'activité physique à évaluer (dépense énergétique, niveau global d'activité, activités durant les loisirs ou au travail, activités physiques intenses), ou au degré de précision recherché. Dans l'ensemble, plus les questionnaires sont précis, moins ils sont pratiques en terme de coût et de durée d'administration. Même si la validité et la fidélité de ces questionnaires sont relativement fiables, ces indices de précision sont parfois incomplets, inadéquats ou indéterminés. Malgré les lacunes des questionnaires, leur utilisation a permis d'établir plusieurs relations entre l'activité physique et certains problèmes de santé. L'amélioration de la précision des questionnaires et de leur validation pour divers groupes de subjets devrait permettre d'identifier des relations encore plus significatives entre l'activité physique et divers facteurs associés à la santé.
Objectives – Operation Everest III (Comex'97) was performed to evaluate the physiological, psychological and pathological mechanisms induced by a prolonged exposure to extreme altitude, up to 8,848 m (altitude of Mount Everest).Methods – Eight male subjects (23 to 37 years old) have been studied in normoxia, then, after 6 d of acclimatization at 4350 m, in a hypobaric chamber (Comex SA, Marseille) where they stayed 31 d, from 5000 m to 8848 m of simulated altitude. Eighteen protocols, from 14 scientific teams, have explored various aspects of acclimatization to extreme altitude.Results – The decrease in plasma volume is one of the factors involved in the reduction of physical performance, as witnessed by the 9% increase in VO2max at 6000 m under infusion of 300 ml hydroxyethylamidon. Ventilatory and cardiac responses to hypoxia at exercise have an opposite trend, with an increase in ventilatory and a decrease in cardiac response. Autoregulation of cerebral circulation is altered above 7000 m. Left ventricular function is maintained up to 8000 m, in spite of an important increase in pulmonary artery pressure. Ventricular relaxation is altered, probably because of altered ventricular filling. The decrease in food intake contributes to the loss of body weight (mean of 5.4 kg). Nutritional habits are modified, with shorter and more frequent meals and a decreased interest for food. Lipolysis in fat tissue is blunted, suggesting, like for cardiac adrenergic receptors, a desensitization linked to a change in G proteins. Few psychological alterations were observed below 6500 m. However, changes in mood state and a high level of anxiety have been noticed and correlated to other physiological or psychometric parameters.Conclusion – Human body is able to develop adequate responsive mechanisms to oppose the severe hypoxia (mean arterial PO2 of 30.6 mmHg at 8,848 m). Mental capacities are also slightly diminished, but only above 6500 m.
Objectives. – To present the eccentric contraction-induced protective effect, as well as the different kind of adaptations possibly involved in this phenomenon.Topics. – The effects of an eccentric exercise session on the neuromuscular system depend on the contraction type performed previously. A repeated eccentric exercise does not induce the same negative effects on force production capacity than a first bout. Indeed, strength recovery is improved and eccentric exercise-induced ultrastructural damages are less pronounced after a second exercise bout performed 5 days to 6 months after the first one.Conclusion. – The protective effect seems to be mainly related to contractile adaptations to eccentric muscular solicitation. Strength training and rehabilitation programs could be improved by taking into account this protective effect.
IntroductionThe aim of the study is to assess the psychological effects of a short-term therapeutical prednisolone intake.SynthesisWe studied, according to a double-blind, randomized cross-over protocol, the effects of a seven day prednisolone intake (60 mg/day) in 10 healthy male subjects on global health and mood state. No significant change was found between the treatments (prednisolone/placebo) in the 15 variables investigated. However, tendencies appeared revealing an increase of self-esteem, personal accomplishment and athletic identification, as well as a decrease in negative affect for the subjects under treatment.Conclusion
These results could reveal a psychological impact of glucocorticoid intake and should be confirmed by a further study with athletes submitted to a more intense physical activity.
Objectives. - Spinning (R) cycle indoor has become a popular cardiovascular activity for group exercise classes. The purposes of this study were to measure the heart rate (HR) response of novice subjects performing 45-min Spinning (R) cycle indoor, and to determine the criterion-related validity of ratings of perceived exertion (RPE) as measure of exercise intensity in novice subjects. Methods. - Fifty-nine subjects ranging from 18 to 38 years (mean +/- SD, age: 32.1 +/- 10.2 years), were recruited from a private fitness club. HR and overall RPE were measured during the session. The Spinning (R) session comprised a warm-up (10 min), and a 25-min trial (cardiovascular phase) of flat, run, seated climb, and standing climb activities followed by a cool down (10 min). Results. - The mean values of the percentage of heart rate reserve (%HRR) and overall RPE in cardiovascular phase were 71.1 +/- 13.7% and 14.2 +/- 1.8 points, respectively. The correlation value between overall RPE and %HRR was moderate to weak, but significant (r=0.41, p < 0.05). Conclusions. - The intensity during indoor cycling class in novice adults ranged from moderate-to-hard values. These data suggest that indoor cycling must be considered a high-intensity exercise mode for novice subjects. The reduced validity obtained for the overall RPE suggests that more studies must be performed before using this scale to regulate exercise intensity in novice adults during indoor cycling class.
This study was designed to specify whether in elderly subjects an individualized training program at the ventilatory threshold gives better results than the standardized training program performed at 50% of heart rate reserve. Sixteen subjects participated in the study. Maximal exercise tests were performed on a treadmill before and after the training program. After the first test the subjects were randomized into two groups (n = 8) and the training heart rate (HRT) was determined. The standardized training group (STG) trained at the standard level of 50% heart rate reserve. The individualized training group (ITG) trained at the heart rate corresponding to the ventilatory threshold. The 3-month training program consisted of 60-min interval walking sessions on a running track twice a week. During the sessions HRT was continuously monitored by means of a cardiofrequency meter. The mean HRT was 129 ± 5 bpm and 115 ± 2.8 bpm in ITG and STG, respectively. The VO2 max was significantly higher in ITG (P intergroup < 0.04): it was increased by 20% in ITG and by 6% in STG. In addition, we observed in the ITG a significant decrease in submaximal ventilation and heart rate. The better results observed in ITG are essentially due to the higher and more individualized heart rate (ITG: 108 – 146 bpm vs STG: 99 – 125 bpm). We conclude that in the elderly, an individualized training program at the level of ventilatory threshold is significantly more efficient, in terms of VO2 max and submaximal cardiorespiratory parameters, than a standardized program at the level of 50% of heart rate reserve.
Purpose – The aim of the study was to assess the improvement in Maximal Anaerobic Power (PMAna) from two tests in soccer players during growth.Methods – The experiment was carried out in 328 players, 11–18 years old, during their stay at the Clairefontaine National Soccer Center. PMAna was measured from the last 10 meters of the a 40 m-sprint test (ST) and a jump test (JT). The skeletal age (AO) is used as reference, and not the chronological one.Results – The results of the two tests are highly correlated (r= 0.8–0.9), PMAna values being always higher in the ST than in the JT.The most significant increase in PMAna occurs between 13 and 14 years AO (+47% for the ST, +27% for the JT), remains still significant up to 16 AO (respectively +38% and +24% between 14 and 16 AO), but the maximum value is reached at 17 AO. Between 12 and 16 AO, the PMAna value is multiplied by 2.29 for the ST and 1.81 for the JT.Conclusions – Sprint and jump tests seem well adapted to estimate PMAna in soccer players. The measure of the skeletal age during growth is needed for a better interpretation of the results. In addition, results obtained during growth allow a reliable estimation of PMAna in adulthood.
L'analyse des différents modèles explicatifs de l'évolution de la performance cognitive lors de la réalisation d'un effort physique indiquent que les résultats inconsistants relevés dans l'approche expérimentale sont liés àdes ≪ effets pluriels et contradictoires ≫. Ces influences diverses sont déterminées, en partie, par les caractéristiques objectives des tâches mais aussi par les représentations des sujets. Il est donc important, à ce niveau, de proposer à chaque sujet un protocole standardisé. Dans ce cadre expérimental, aucune des hypothèses ne peut être a priori rejetée, et la prévision des performances dans la tâche cognitive reste délicate car elle dépend étroitement de facteurs individuels qui interviennent dans l'activité du sujet. La première hypothèse suggère un effet de l'activation sur la performance cognitive médié par l'exercice physique. Celui-ci semble être complexe. D'une part il est difficile d'établir une relation linéaire entre activation et effort physique, d'autre part, les modèles multidimensionnels de l'activation intègrent dans la relation entre exercice et processus cognitifs les effets indirects des traits de personnalité, ou encore de l'investissement des sujets. La seconde hypothèse est issue du paradigme de la double tâche. Dans une situation où le sujet réalise deux tâches en même temps, une tâche de pédalage et une tâche cognitive, les modèles expérimentaux suggèrent une dégradation de la performance en fonction de la priorité accordée à l'une où l'autre des tâches. Enfin l'effet de l'exercice peut également se traduire par l'adoption par les sujets de stratégies à risque privilégiant la vitesse de réponse au détriment de la justesse. Aussi, pour clarifier la diversité des résultats expérimentaux, les futures recherches menées dans ce cadre devront considérer a priori les multiples biais méthodologiques qui pourraient induire des interférences entre les différents modèles théoriques sous-jacents.
AimsThis review focuses first of all on the effects of the cold and/or contrast water immersion techniques on muscular recovery to determine practical implications for athletes. Then, the present review summarizes the effects of whole-body cryotherapy and its potential benefits.ActualitiesThe multitude of protocols concerning the cold water immersion technique and the contrast water technique explains the large variety of the results reported in the literature on this topic. This recovery strategy seems mainly recommended after strength training and anaerobic solicitations, when it is planed during the 20 min following the fatiguing task. Immersion in warm water is not supported by the literature; only the depth of the immersion looks essential, an immersion to the neck is associated with positive effects. Concerning the whole-body cryotherapy, few data are available about its benefits on recovery after exercise. Nevertheless, the literature reports interesting results on its positive impact relating to inflammatory factors, antioxidant status, mood and syndromes of depression.Perspectives and prospectsFurther studies are needed to investigate the potential positive effects of whole-body cryotherapy on recovery by athletes.
Objective. – The aim of this study is to determine if the diminished aerobic capacity of coronary artery disease patients is accompanied by a impaired peripheral skeletal muscle function compared to healthy control subjects.Methods. – Thirteen coronary patients and 9 healthy control subjects (57 ± 7 vs 55 ± 8 years) have realised both a maximal laboratory exercise testing and an assessment of the peripheral skeletal muscle function on a isokinetic apparatus (Cybex Norm II). The cardiorespiratory and mechanical parameters (VO2 uptake, VE, HR and Power output) were measured at ventilatory threshold and maximal effort during a cycloergometer testing. The peripheral skeletal muscle function of the quadriceps was assessed from the maximal voluntary isometric force (MVIF) and from static endurance time (SET) at an intensity of 50% of the MVIF.Results. – Coronary patients showed a diminished aerobic capacity at maximal effort (VO2max: 23.56 ± 8.1 vs 42.43 ± 9.74 ml min–1 kg–1, p < 0.0001; VEmax: 67.07 ± 16.85 vs 90.15 ± 20.76 l min–1, p < 0.01; HRmax: 110 ± 17 vs 153 ± 20 beats min–1, p < 0.0001; Pmax: 133 ± 40 vs 233 ± 39 W, p < 0,001) but also at ventilatory threshold (VO2: 15.81 ± 5.7 vs 29.61 ± 7.8 ml min–1 kg–1, p < 0.001; HR: 92±11 vs 135±21 beats.min–1, p < 0.0001, P: 88 ± 32 vs 153 ± 39 W, p < 0.001) except for VE (VE: 38.98 ± 9.91 vs 46.68 ± 7.03 l min–1, NS). No difference was found between the MVIF (MVIF: 230 ± 46 vs 228 ± 21 N m–1, NS) between coronary patients and control subjects whereas the SET is lower in coronary patients (65 ± 19 vs 88 ± 9 s, p < 0.003).Conclusion. – Coronary artery disease patients have a lower aerobic capacity accompanied by a impaired peripheral skeletal muscle function.
Aim. - To assess the injury profile in young mate and female karate athletes. Patients and methods. - Subjects (218 boys and 84 girls, 7-15 years) were competing at an Open Dutch Karate Championship. Data were collected with simple check-off forms that described the athlete and nature, site, circumstances and severity of the injury. Injury rates were calculated per 1000 athletes-exposures (AE). Relative risk (RR) was calculated as well, as the 95%CI around the injury rates. Results. - There was no difference in injury rate between boys and girls: 99.74 per 1000 AE (95%CI: 77.32-122.16) versus 115.11 per 1000AE (95%CI: 75.23-154.99). The girls were also not at a higher risk of incurring an injury (RR=1.093, 95%CI: 0.788-1.516, p=0.596). In the boys, the head and neck were more likely to get injured compared to the upper extremities: RR=2.65 (95%CI: 1.39-5.03, p=0.003). In the girls, although there was no significant difference between the injury rates of the head and neck and the upper extremities, the head and neck were at a higher risk to sustain an injury: RR=3.50 (95%CI: 1.29-9.49,p=0.014). In the boys,the mechanism of injury tended to involve a punch compared to a kick: RR = 1.41 (95%CI: 1.00-2.00, p = 0.053). Conclusion. - The head and neck were at higher risk to sustain an injury, while punches were the main injury mechanism.
Introduction – The aim of this study was to investigate the relationship between velocity and accuracy in standing shooting in eight biathletes of national level.Facts – Shooting accuracy was measured under exercise condition during eight shooting trials, which duration was progressively reduiced.Conclusion – The results showed a significant 2nd order polynomial relationship (p < 0.05; r2 = 0.24) between shooting accuracy and velocity. This relationship suggests that there is an optimal shooting period estimated between 15 and 20 s. This optimal shooting period may result from visual adjustments and cardio-ventilatory responses produced by the exercise intensity preceeding biathlon standing shooting.
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.
Topics - The number of people reaching advanced adult age in many countries of the world has increased dramatically in the last century, The main problem associated with aging is the loss of functional capacity and independence. An important contributor to this problem is the age-related decline in muscle mass (sarcopenia) and strength seen in both men and women. Longitudinal studies show a loss of approximately 1-2% per year in isokinetic strength of the knee. Changes in the elbow flexors and extensors were less dramatic and more significant in men than women. Although muscle atrophy is a significant contributor to the weakness seen in the elderly, single fiber studies have demonstrated a loss of muscle fiber quality (specific force). This may be due to alterations in the myosin molecule. Perspectives - Strength training has been shown to partially reverse age-related losses in muscle function, Progressive resistance training results in dramatic increases in muscle strength, significant hypertrophy (although to a lesser degree), an increase in protein synthesis, an increase in muscle fiber specific force, and changes in functional tests such as walking speed and stair-climbing power. It remains to be seen whether the myosin molecule is altered with strength training. (C) 2002 Editions scientifiques et m6dicales Elsevier SAS.
Aims of the study. - The aim of this study is to investigate the behavior of the physiological, biochemical and psychological parameters in Brazilian soccer players during a training program. Materials. - Fifteen athletes were evaluated at the beginning (T1), in the middle (T2) and at the end (T3) of the training program. On the first day, at 7:30 am, before the blood collecting at rest for the determination of serum creatine kinase (CK), serum creatinine and serum urea, the athletes had their psychological parameters assessed by the profile of mood state questionnaire (POMS). After 90 min, they performed a 250-m sprint. On the second day at 8:30 am, the athletes had their alactic anaerobic performance measured and, after 40 min, they completed the aerobic test. Friedman test was used to verify the behavior of overtraining markers. Results. - There was a decrease in vigor score in T3 (p=0.01) compared with T1 and T2. In T3 (p=0.01), the athletes also showed an increase in serum creatinine levels compared to T1. Furthermore, in the same period, we verified a diminishing in the team performance. Conclusion. - The training program developed between T2 and T3 led to the fall of the vigor score, the increase in serum creatinine concentrations and the diminishing in team performance. (c) 2007 Elsevier Masson SAS. All rights reserved.
Introduction.— Adaptative changes following muscular electrostimulation were investigated in the horse.Method.— A 3-week period of electrical stimulation with 13 sessions of 25 minutes have been realized tor ten horses. The sessions are composed of the alternation of 4 second-tetanic contractions with a 70 Hz frequency current and 12 second-rest periods with a 5 Hz frequency current. On all the animals, the shoulder's and thigh's muscles have been symetrically stimulated.Results.— Any significative difference have been shown after electrostimulation on the thickness of shoulder's muscles. Blood lactate concentrations'analyses before and after a same exercise-test has shown a significant decrease after electrical stimulation (P < 0,001). Blood aspartate aminotransferase's concentrations have significantly increased at rest (P < 0,05) and half an hour after the exercise (P < 0,01) whereas the rise in blood creatine phosphokinase's concentrations are not significative.Conclusion.— All of these results in the horse suggest, like in other species, a better strain resistance of muscular fibers after electrical stimulation. A longer study and/or a protocol with more sessions would be necessary to precise the electrostimulation's effects on the muscular development in the horse.
Objectives.To consider the various heart murmurs possibly detectable at the time of examination before approving the practise of sports in the child, the means necessary for the diagnosis and the management concerning the athletic activities.Background.Usually the murmur is harmless (or anorganic) and, according to the site, four types can be described in children. Generally the auscultation allows the diagnosis and the complementary investigations are unnecessary, especially the echocardiogram. The organic murmurs undiagnosed before the examination are very uncommon and lead to evoke: at the endapex an interventricular muscular septal defect or an hypertrophic cardiomyopathy; at the left sternal border an atrial septal defect; at the basis of the heart a minor aortic valve stenosis. The echocardiogram is then necessary for diagnosis confirmation and to precisely evaluate the cardiopathy. In the majority of the cases the athletic activities will be approved, eventually after exercise test or/and Holter registration.Conclusion.The clinical data alone should allow the assertion of the murmur's mechanism and the always costly complementary investigations are unnecessary in the majority of the cases.
Aim. – The goal of this study was to clarify the precise role of carnitine in the normal function of muscle cell and to determine the rational for carnitine suplementation in improving physical performance.Recent data. – Recently, new data have been reported concerning the biosynthetic pathway for carnitine as well as its intracellular transport across plasmic membranes. Molecular basis for carnitine deficiency has also been described allowing a better understanding of biochemical mechanisms involved in carnitine utilization by muscle cell. A exhaustive analysis has been conducted to determine the role of carnitine in muscle physiology. Taken together, the available data show that a carnitine deficiency in muscle cell is responsible of a major dysfunction in this tissue characterized by a myopathy usually associated with neurological disorders. On the other hand, supplementation of healthy people does not improve their athletic performances and does not markedly change biochemical muscle parameters.Perspectives. – In conclusion, carnitine is an essential element in the oxidative pathway and its absence causes serious muscle disorders but supplementation has no major effect on muscle function.
Aim. - This study aimed to examine the association between active vs. inactive lifestyle and cellular and humoral immune system in the elderly. Methods. - Eleven elderly male athletes (mean age +/- S.D.: 67.1 +/- 6.0 year) performing regular aerobic exercise for about 38.8 +/- 18.5 yeasr (4.4 +/- 1.4 d week(-1); 10.0 +/- 8.1 h week(-1)) and eleven male individuals at similar ages (mean age S.D.: 64.9 +/- 4.6 year) leading a sedentary life were taken as control group. Immunological assessments were total leukocyte count, lymphocyte subpopulation, natural killer percentages, and IgA, IgG, and IgM concentrations. Results. - Baseline NK cell percentage, and serum IgA and IgM concentrations of master athletes were significantly higher than those of control group (29.3 +/- 12.8% vs. 20.0 +/- 7.5%; 2.4 +/- 0.66 g/l vs. 1.6 +/- 0.63 g/l; 1.0 +/- 0.47 g/l vs. 0.58 +/- 0.31 g/l, respectively; P < 0.05). No statistical differences were obtained in the total leukocyte counts and neutrophils, eosinophils, lymphocytes, monocytes, and the percentages of total T cells, B cells and T cell subsets (CD4+ T cells, CD8+ T cells), and IgG levels of the two groups. Conclusion. - Habitual exercise training may cause a slow down in the age-related decline in NK cell percentages and serum IgA and IgM levels of the elderly.
Objective. – To evaluate the impact of a rugby match in term of energetic demand and the post-match recovery during the days following a rugby match in national level referees.Results and discussion. – A rugby match corresponds to an intense aerobic activity, with a total distance covered of 7,532 ±1,081 km and a mean heart rate 160 ±11 in 35 ±4 years aged referees. During the match, the salivary cortisol level rises to 3 fold pre match level, showing a high physiological constraint. During the five following days, awakening cortisol levels were similar to basal one, meaning that this activity does not induce recovery difficulties in the subjects of this study.
The aim of this study was to establish heart-rate and systolic blood pressure during exercise-tests in healthy children. Protocols used included treadmill (Bruce protocol) and bicycle (30 or 20 watts/3 minutes). Paediatric population was divided according to age, weight and body surface area. Correlations between working capacities and anthropometric characteristics (weight or body surface area) were not better than with age of the subjects (0.75–0.77). Variability of the time of exercise was greater on bicycle than on treadmill. Heart-rate decrease with age at rest, was quite similar at peak exercise, and return to baseline value quicker in younger subjects. Systolic blood pressure increased with age at rest and peak-exercise, whatever sex or protocol used.
Objective. – Energy solicitation during a judo match and the kinetics of recovery were assessed by measuring the metabolites of oxypurine cascade level and the glycolytic pathway.Methods. – Venous blood samples were taken from sixteen national judo athletes (aged 18.4 ± 1.6 years), before (T1) and at 3 minutes (T2), 1 hour (T3) and 24 hours (T4) post-match. A 7-day diet record was used to evaluate the values for nutrient intakes.Results. – Nutrient analysis indicated that these athletes followed a low carbohydrate diet. Plasma lactate concentration rose to 12.3 ± 1.8 mmol l–1 at the end of the match. An increase in extracellular markers of muscle adenine nucleotide catabolism, urea and creatinine levels was observed at T2 while uric acid levels remained unchanged. Persistent high concentrations of urea were observed during the post-training recovery period for 24 h. Ammonia, hypoxanthine, xanthine and creatinine values returned to their control levels within 12 h of recovery. Uric acid concentrations rose from T3 and did not return to baseline 24 h after the match.Conclusions. – These results showed that a judo match induces mobilisation of protein metabolism.
IntroductionIron overload may be primitive or secondary. Recently dysmetabolic hepatosiderosis syndrom has been demonstrated in secondary etiologies.SynthesisHigh uptake of iron by sport people is very frequent. Secondary iron overload and associated metabolic disorders are increased by erythropoietin use. In three observations, we found fast progressive high levels of ferritin in relation with the recent use of injectable iron and erythropoietin.Conclusion
We think that similar biological presentation allows the development of iatrogenic secondary dysmetabolic hepatosiderosis in this situation. Consequently, we observe iron overload as well as enzymatic and metabolic disturbances in relation with iron and erythropoïetin abuse.
Soccer is the most popular sport in the world. Over the last 20 years, there has been an explosion in women's soccer. Women make up 22% of the world's soccer players, and in the US, women represent 43% of all soccer players. This activity presents an aerobic impact which is not to be neglected (max VO2 between 47 and 56 mL/mm/kg), even though these results are lower than those found in male soccer players. The same types of traumatic soccer injuries are found between female and male players, but there are, however, notable differences. Ankle sprains are found with the same frequency in female and male soccer players. In contrast, knee injuries are found more often in female players, especially anterior cruciate ligament tears. The reasons for these differences are certainly multifactorial, although there is a clear relationship between soccer injuries and both the level of fitness (which is lower for females than for males) and the differences in the maximal hamstring torque and recruitment of that torque. In contrast, it does not appear that hyperlaxity, which is more common in females, is in itself a risk factor. Finally, as for female athletes who specialize in long distance running, one finds certain characteristics common to both groups, such as more frequent episodes of amenorrhoea, the loss of bone mineral density, and a higher risk of stress fractures. Furthermore, the risk of traumatic injury appears to increase during the premenstrual phase, although it appears to be lower in women using contraceptive pills. As for male soccer players however, there is a development of preventative programs that will allow a reduction in the number of traumatic muscle injuries.
Acute exposure to altitude may induce signs of altitude illness, such as pulmonary edema. This edema seems to be linked with hypoxic vasoconstriction and increased pulmonary pressures due to hypoxia. During strenuous exercise in normoxia, highly trained athletes also showed increased pulmonary pressures as well. We may thus raise questions about the role of pulmonary edema in the exercise-induced hypoxemia exhibited by highly trained endurance athletes, as well as the acclimatization of this population to altitude.
Objective. - The aim of this Study was to design a high intensity swimming training and two-kidney, one-clip (2K1C) hypertension protocol in Sprague-Dawley (SD) rats and to use current echocardiography techniques to examine the differential diagnosis between physiological and pathological left ventricular hypertrophy. Methods. - One group of SD rats performed swimming training at high intensive swimming training (HIGH) for eight weeks. In animals of the other arm of the study, a 2K1C hypertension was created and maintained for eight weeks. Results. - After eight weeks, all rats were studied by standard and tissue Doppler echocardiography. The heart weight/body weight ratio (HW/BW) of 2K1C and HIGH rats increased by 16% and 42%, respectively. Echocardiography showed increased septal and posterior wall thickness in both the 2K1C and HIGH rats. Left ventricular increased by 35 and 41 % respectively. Left ventricular diameters, stroke volumes, cardiac output, and ejection fractions were unchanged in either group. Mitral inflow showed it decrease in late-wave velocity, thus increasing the E/A ratio in HIGH rats. However, mitral inflow showed an increase in late-wave velocity, thus decreasing the E/A ratio in 2K1C rats. There was a significant increase in Ea and early diastolic (Em)/late diastolic (Am) in HIGH rats in basal septum and lateral mitral valve annulus. And there was a significant increase in Am, which led to a significant decrease of Em/Am in 2K1C rats. No significant change occurred in pulmonary vein systolic velocity and diastolic velocity, in either of the three animal groups. However, there was significant increase in atrial reversal velocity in HIGH rats. Conclusions. - Doppler echocardiographic parameters of LV diastolic function can be of diagnostic importance for discrimination between pathologic and physiologic LV hypertrophy.
A review of various literature results on recent aspects of protein metabolism during muscle exercise provides the necessary information to define protein nutritional requirements of athletes, and to specify the role of hormones. Protein synthesis is decreased and structure protein catabolism is increased after prolonged physical exercise. These processes yield free amino-acids which become available for energetic metabolism. Branched amino-acid oxydation increases in muscle, and amino-acids move to the liver where they are incorporated into neoglucogenesis. These metabolic phenomena induce an integration of amino-acids into the tricarboxylic cycle and speed the combustion of glucose and fatty acids, increase the production of sus-hepatic glucose and yield substrates which can be metabolized to permit muscle contraction. The results is an increase in protein needs during regular physical training. Endurance activities require the highest protein intakes. A safety intake for a very intense sports activity can be approximately 2 g/kg/day. The role of hormones in protein metabolism changes induced by physical exercise is considered based upon knowledge acquired in fundamental physiology of the trophic role of hormones on muscle tissue. This suggests an anabolic and trophic role of insulin, testosterone, growth hormone, thyroid hormones and catecholamines at physiological concentrations and a catabolic role of glucocorticoids. However, each one of these hormonal axes acts separately on contractile or non contractile proteins. It is therefore difficult to establish a systematic relationship between a hormonal effect, the gain in lean mass and the performance. The functional relationship between the hormonal response and the protein intakes evidences the role of a well balanced protein supply for optimal muscle development. However, many areas remain to be explored regarding the qualitative nature of protein intakes during physical training.
AimPerformances in Olympic triathlon Age Groups World Championships were analysed to evaluate the decline in maximal performance with increasing age in male and female triathletes.Method
Mean performance of top ten performers were analysed for each group of age during the last Age Groups World Championships events using the exponential model proposed by Baker et al. [Exp Aging Res 29 (2003) 47–65]. Constants of the exponential model were compared between men and women.Results and discussionThe decline in triathlon performance follows the exponential model. The statistical analysis shows a significant gender effect on the period of decrease in performance. In male subjects, performance loss does not appears before 45 years, whereas in female, it appears earlier (40 years). In both populations, significant decrease is observed after 50 years.Conclusion
Our study during a multimodal mode of locomotion activity is in agreement with previous results reported during an unimodal activity. However, triathlon performance decline appears later suggesting an effect of locomotion mode. In this study, gender effect is similar with those reported previously. Further explicative studies are necessary to analyse these observations.
Objectives. – The aim of this symposium entitled “Muscle plasticity and regeneration” was devoted to put in touch several international scientists on issues that concern skeletal and cardiac muscle, their adaptive responses to physical training, and characteristics of their recovery.Topics. – Professor James Skinner is involved in an extensive study whose objective is to examine the role played by the genetic basis of responses to physical training and of concomitant changes in risk factors for cardiovascular and metabolic diseases (HERITAGE study). During this study, he showed that expected changes in the maximal oxygen uptake (a marker of the positive responses to training) depended neither on gender, race, age, nor on initial physical fitness. Therefore, all these results clearly suggest that the “high-responder to training” phenotype vary according to the interaction between many genes and between these genes and environment. The gene encoding for the angiotensin converting enzyme was one of the potential genes able to account for the high, early and complete response to physical training. Results of the Heritage Family Study were not in accordance with this hypothesis and nothing clearly suggests that the I variant of the human ACE gene was involved in the extent of adaptive responses to repeated exercise.Many studies have been published during these last years, with the purpose to examine the molecular mechanisms that explain, at least partly, the adaptive muscles responses to physical training. Marked and significant advances have been done to explain the molecular and cellular events involved in the training-induced increase in mitochondrial density within skeletal muscle; alteration in the balance of the intracellular energy status is one of the major events involved in the AMP-activated protein kinase (AMPkinase activation). AMPkinase activation increases the expression of a transcription factor (PGC-1α PPAR-γ coactivator-1α) that coordinately controls the expression of both nuclear and mitochondrial genomes. Endurance training also induces an increase in the muscle capillary bed. This increase is mainly related to an enhanced vascular endothelial growth factor expression (VEGF). Exercise-induced intracellular hypoxia is one major event of VEGF gene expression during exercise. The effects of strength training on skeletal muscle result mainly on changes in muscle mass. Considerable advances have been done to understand the molecular mechanisms and interaction involved in the signalling pathways activated by insulin-like growth factor-1 (IGF-1). On the other hand, inhibition of the ubiquitin–proteasome pathway could be important to increase muscle size during strength training; a particular attention has been paid on the activation of two enzymes, namely muscle ring finger 1 (Murf1) and muscle atrophy F-box, ou Atrogin-1 (MAFbx) which are required for ubiquitin–ligase activity.Interleukin-6 (IL-6) plays a special and specific physiological-role on the training-induced muscle responses. Prolonged exercise is associated with an increase in plasma IL-6, which results from an enhanced production by skeletal muscle. Production of IL-6 in contracting skeletal muscles can account for the exercise-induced increase in plasma IL-6. An inverse relationship was shown between muscle cytokine production and muscle glycogen availability; muscle-derived IL-6 is released into the circulation during exercise and is likely to exert an effect on the liver and adipose tissue, thereby contributing to the maintenance of glucose homeostasis during exercise and mediating exercise-induced lipolysis. These results indicate that IL-6 may represent an important link between contracting skeletal muscles and exercise-related metabolic changes, and should be viewed as an important biochemical factor to account for the exercise-related metabolic and immune changes, and recovery.Future prospects. – Taken together, these results clearly have a major impact in exercise physiology and muscle biology. They contribute to improve our knowledge on the acute and adaptive muscle responses to changes in workload, and on muscle recovery. Moreover, these researches have a potential impact in the medium term to develop pharmacological treatments and strategies devoted to avoid muscle inactivity.
Reasons for recommending regular physical activity to the older individual include the potential for both a prolongation of working career and an avoidance of partial or total dependency in the final years of life. In both the workplace and the activities of daily living, the performance of elderly subjects is enhanced by training-induced increases of aerobic power and muscle strength. The effects of a well-designed training programme can offer the equivalent of a 20-year reduction in biological age. During the retirement years, valuable functional gains are also realized through improved reaction speed, enhanced flexibility, stronger bones, and improved metabolism. A reduced risk of conditions such as atherosclerosis, diabetes and osteoporosis eliminates much chronic disability and can extend overall lifespan by 1-2 years. More importantly, the improved functional ability curtails the 8-10 years of terminal disability seen in a typical sedentary person. An exercise regimen may thus extend the quality-adjusted life-expectancy by several additional years. The physiological mechanisms underlying the deterioration in physical performance are briefly reviewed. In most instances, the functional disturbances can be at least partially reversed by exercise, although the inherent rate of aging is not greatly changed. Trainingresponses occur somewhat more slowly than in a younger person, but the physiological mechanisms of benefit are generally similar in young and older individuals.
Aim. - Analyze the effects of exercise training on cardiac sarco endoplasmic reticulum calcium ATPase (SERCA) 2 gene expression of genetically obese Zucker rats, an animal model of non-insulin dependent diabetes mellitus (NIDDM). Methods. - Twenty male and 20 female Zucker fatty rats ran 30-50 min/d at 35-40% VO2max, 6 d/week for 13 weeks. Semi-quantitative RT-PCR associated with specific restriction fragment analysis was used to detect and quantify the relative expression of SERCA mRNA isoforms. Results. - Fatty rats had an enhanced expression of SERCA2 and phospholamban (PLB) mRNA levels in ventricles. Moreover, fatty rats exposed to a moderate treadmill running exercise for 13 weeks exhibited a significant increase in ventricles SERCA2 mRNA levels, whereas, no change occurred in control lean rats. Exercise training produced a significant induction of a-myosin heavy chain mRNA levels only in fatty rats. Conclusion. - We hypothesize that exercise training may improve the cardiac function in diabetic rats by increasing the mRNA expression of SERCA2 since it is known that NIDDM rats have a reduced left ventricular diastolic compliance, and that exercise training improves the ventricular function in diabetic rats.
Objective. - Wrist problems are common in grip sports. To better understand the entrapment symptomatology of the different neurovascular passages of the wrist, an anatomical revision seems necessary because confusion and error has increased lately. This study will focus on the ulnar canal. Comparison of the original description of the canal with definitions emanating from scientific papers, anatomical handbooks and Internet websites reveal various differences, which may create clinical confusion. Design. - With the original paper of Guyon as a reference, comparison was made (i) with 37 cadavers (74 wrists); (ii) with an Internet search and; (iii) with a bibliographic survey. The dissections allowed for the verification of Guyon's description and were used to illustrate the findings. Results. - Dissection of 74 wrists confirmed Guyon's original description. Out of the 2559 Internet hits, papers in English, French, German and Dutch were considered, only. The Internet websites and the published material presented an erroneous images and/or explanations. Conclusion. - Dissection and bibliometry suggest that the canal has received multiple denominations including a confusion with the "canalis pisohamatum". This confusion is situated on Internet sites, in scientific/clinical papers and in "classical anatomy literature". A better understanding of this region will undoubtedly enhance our knowledge of entrapment pathologies. (c) 2007 Elsevier Masson SAS. All rights reserved.
Introduction – The aim of this study was to determine the effects of a fast walking training program on maximal oxigen uptake and perceptive motor skills in healthy active elderly subjects.Methods – Nine subjects, 63 to 69 years old, had a twelve week walking training (one-day bouts of exercice, five times a week), with an average intensity at the anaerobic thresehold level. Direct measurements of oxigen uptake on treadmill and perceptive motors skills (reaction time, postural regulation, motor dexterity) were performed before and immediately after the training program. Before training program, we found a good level of aerobic physical fitness in this elderly population for their age. After the training period, we found a significant increase in maximal oxigen consumption (p<0.01), but there were no significant change for motor skills.Conclusion – So, even if motor skills seemed not to be influenced by aerobic training program, however this program remains of interest on a metabolic point of view.
Aim. - This study aimed to test if investigate whether the anaerobic work capacity is replenished while exercising at critical power intensity. Then, a known exercise duration, which demands high anaerobic energy contribution, was compared to intermittent exercise duration with passive and active (cycling at critical power intensity) rest periods. Methods. - Nine participants performed five sessions of testing. From the 1st to the 3rd sessions, individuals cycled continuously at different workloads (P-high, P-intermediate and P-low) in order to estimate the critical power and the anaerobic work capacity. The 4th and 5th sessions were performed in order to determine the influence of anaerobic work capacity replenishment oil exercise duration. They consisted of manipulating the resting type (passive or active) between two cycling efforts. The total exercise duration was determined by the sum of the two cycling efforts duration. Results. - The exercise duration under passive resting condition (408.0 +/- 42.0 s) was longer (p<0.05) than known exercise duration at P-intermediate (T-intermediate = 305.8 +/- 30.5 s) and than exercise duration performed under active resting conditions (T-active = 304.4 +/- 30.7s). However, there was no significant difference between T-intermediate and T-active. Conclusion. - These results demonstrated indirect evidence that the anaerobic work capacity is not replenished while exercising at critical power intensity.
The aim of the study was to examine cardiac solicitation induced by the 5-minutes running field test (5RFT) for maximal aerobic velocity measurement. The study was carried on 48 males of varied physical fitness, with VO2max ranging from 33 and 71 mL O2·min−1·kg−1. Heart rate (Hr) was recorded all along the tests every 5 seconds. Hrmax measured at the end of an aerobic test is a criterion of the maximal quality of this test; generally a 90% theoretical Hrmax is required. Our subjects reached 93% of their reference Hrmax (192.0 ± 7.5 bpm) from the first minute of the trial. They performed the whole test at an intensity close to Hrmax and reached it at the end of the 5RFT. Hr values obtained during the test allow to conclude that 5RFT is conform to the rank required for a Vamax test measurement.
L'objectif de ce travail était de valider le test navette de 20 m et le test de piste pour l'estimation de la consommation maximale d'oxygène V̇O2 max) chez le sportif. Vingt-six sujets sportifs des deux sexes, âgés de 18 à 30 ans, ont participé à cette étude. La V̇O2 max a été déterminée en laboratoire par la méthode à charge croissante en circuit ouvert sur ergocycle. Sur le terrain, elle a été estimée à l'aide du test navette avec paliers de 1 min et du test de piste avec paliers de 2 min. Les résultats montrent que les valeurs de la V̇O2 max ne diffèrent pas significativement quelle que soit la technique utilisée pour sa détermination (F = 1,9; P = 0,15). La V̇O2 max déterminée par le test navette et par le test de piste est supérieure à celle déterminée au laboratoire de 3% et de 7% respectivement, mais ces écarts ne sont pas significatifs. Le coefficient de corrélation obtenu entre la mesure directe et le test navette (r = 0,87; P < 0,001) est meilleur que celui obtenu avec le test de piste (r = 0,64; P < 0,01). Quand on compare les résultats des tests de terrain entre eux, les valeurs de V̇O2 max déterminées par le test de piste sont supérieures. Toutefois, on se demande si les valeurs du test navette ne sont pas limitées par sa technique elle-même, la capacité anaérobie lactique et/ou cardiovasculaire. En conclusion, cette étude a montré que le test navette avec paliers de 1 min et le test de piste avec paliers de 2 min évaluent de façon satisfaisante la consommation maximale d'oxygène chez le sportif.
AimsTo develop a faster segment length measurement method than the classical one proposed by the ISAK without modifying the nature and accuracy of the measurements.Methods
Nine segment lengths were chosen and evaluated in 12 subjects with the ISAK method as the “gold standard”. The method proposed herein included the marking of anatomical landmarks on the skin and the scanning of these landmarks with a digitizing arm used in computer aided design of mechanical parts. In order to obtain acceptable data, the subject had to stand in a stabilizing device conceived exclusively for this purpose.ResultsPaired T-tests between data collected from both methods indicates that a significant difference exists only for the forearm measurement (P = 0.009). The new method is therefore adequate for all segment lengths except at the forearm, where prosupination must be standardized.Conclusion
The time saved with this new method, which is its main advantage, was estimated at 42% in these settings and increases with the number of length measurements on each subject. The proposed method is thus well suited for large measurement volumes or if the time spent with the subjects implies significant costs.