Training-induced changes in aerobic aptitudes of professional basketball players.

We investigated the effects of a training program on the aerobic aptitudes and the relevance of the instant of equality of pulmonary gas exchange (i. e., RER = 1.00) to assess these effects in professional basketball players. Eight athletes performed two incremental exercise tests on a cycloergometer separated by 4.7 +/- 0.7 months. Physiological variables recorded during these two tests (heart rate, oxygen uptake, carbon dioxide output, respiratory exchange ratio, power output) allowed to determine the first and second ventilatory thresholds and the instant of equality of pulmonary gas exchange. The training program induced significant variations of resting heart rate, oxygen uptake and power output measured for the instant of equality of pulmonary gas exchange. Moreover, the used fractions of heart rate, oxygen uptake and power reserves for the instant of equality of pulmonary gas exchange and the second ventilatory threshold increase significantly. Inversely, maximal oxygen uptake, maximal power reached and the used fractions of reserves for the first ventilatory threshold do not differ significantly. Professional basketball training is not focused on drills aiming to enhance both the aerobic power and aptitude, our results suggest that this training program induce the same physiological changes as a typical aerobic training. We also demonstrated that the instant of equality of pulmonary gas exchange is a powerful tool to quantify the changes in aerobic aptitudes during a sport season.

Reproducibility of the instant of equality of pulmonary gas exchange and its physiological significance.

AIM: The goal of this work was to highlight the effectiveness of a new submaximal exercise index of aerobic endurance using a single incremental test: the time at which oxygen uptake and carbon dioxide output are equal, i.e., when the respiratory exchange ratio (RER)=1.00. We studied 2 experimental sets, the 1(st) to assess the reproducibility and the variability of measured variables, the 2(nd) to assess the physiological significance of the instant RER=1.00. METHODS: The 1(st) group consisted of 8 subjects who performed 3 maximal ramp tests, the 2(nd) of 32 athletes. All subjects performed an incremental ramp test until exhaustion with determination of 1(st) and 2(nd) ventilatory and lactic thresholds (VT(1)-LT(1), VT(2)-LT(2)) and the RER=1.00 instant. RESULTS: There was no significant difference in the used fractions of reserves (UF r) for heart rate, oxygen uptake and power output for RER=1.00 between tests, the coefficients of variation being non-significant. In group 2, there were no significant difference of UF r between VT(1) and LT(1), VT(2) and RER=1.00, LT(2) and RER=1.00. In contrast, VT(2) differed significantly from LT(2). CONCLUSION: Measurement of the instant of equality of pulmonary gas exchange was therefore reproducible with a low intraindividual variability. Moreover, it exists a concordance of the apparitions of VT(1) and LT(1) and between these of RER=1.00 and VT(2) and LT(2). Thus, with the instant RER=1.00 provides the physiologist and the sports physician with an efficient submaximal tool to evaluate aerobic endurance of athletes using a single incremental exercise test.

Branched-chain aminoacids and retraining of patients with chronic obstructive lung disease.

BACKGROUND: The aim of this work was to improve the efficacy of rehabilitation by retraining, by oral supply in branched-chain aminoacids (BCAA). Patients with chronic respiratory insufficiency mainly suffer from obstructive bronchitis due to tobacco or asthma. Nutritional assessment is one of the components of respiratory rehabilitation, with retraining. Intense physical training for several days negativates the nitrogen balance, the beginning of a training programme for sedentary patients increases their need in proteins. An additional supply in branched-chain aminoacids increases proteic anabolism, by synthesis increase and catabolism slackening of proteins. Moreover it is known that exposure to high altitude reduces lean mass by inducing a muscular atrophy, which can be avoided by the BCAA provided. This leads to wonder if extra supply of BCAA could play similar role in muscular mass loss induced by pathological chronic hypoxia. METHODS: The prospective and comparative survey carried out in Toki-Eder (private hospital in Cambo) consisted in supplying (during five weeks or more) 30 retrained patients suffering from chronic obstructive bronchitis, and in matching them with 30 witnesses (obstructive patients retrained without additional supply in BCAA). Their mean hypoxemia amounted to 7 torr for age. RESULTS: Each of them improved their reached maximal power, and their VO2 SL, very highly significantly. Each of them developed a moderate metabolic acidosis (whose possible mechanisms are discussed) and slightly increased their ventilation at rest. On the other hand only the supplied patients improved their PaO2 at rest highly significantly, a result which poses the question of the responsible mechanism, most likely a decrease of pulmonary shunt effect. The hypotheses concerning the acid load due to BCAA ingestion are discussed. Only the supplied patients developed hypocapnia expressing a gaseous alkalosis which might be due to a direct effect of BCAA on the respiratory centers. CONCLUSIONS: This observation could have practical outcomes in the management of rehabilitation of chronic respiratory insufficiency: it should be useful to systematically supplement the patients with BCAA during their retraining in order to obtain a more effective improvement of their respiratory function.

Study of blood flow parameters measured in femoral artery after exercise: correlation with maximum oxygen uptake.

To study the recovery periods of blood flow parameters in muscles after anaerobic exercise, instantaneous and mean blood flow velocity curves were recorded in the femoral artery in 22 sportsmen at rest and during the first 4 min of recovery after exercise (Ruffier-Dickson test). A flat ultrasonic probe connected to a Doppler system (Flow-Tester) was fixed on the skin at the level of the common femoral artery. From Doppler recordings, we calculated periods of recovery (return to baseline) of femoral blood flow velocity (FBFV RP), heart rate (HR RP) and femoral stroke distance (FSD RP). Also, Ruffier-Dickson index (RDI), VO(2)max in mL/kg(-1)/min(-1) and number of training hours were determined. We observed a high correlation between FBFV RP and VO(2)max (p = 0. 0002), and significant correlation between FSD RP and VO(2)max (p = 0.0238) and RDI (p = 0.0451). In conclusion, there is a excellent correlation between blood flow velocity recovery period in femoral artery after moderate exercise and VO(2)max in high-level sportsmen. The method of testing is simple and based on conventional Doppler technique. It can be used for the follow-up of training levels in sportsmen.

[Assessment of physical and sports aptitudes, overtraining prevention, and prevention of doping]. / Evaluation de l'aptitude aux activités physiques et sportives, prévention du surentraînement et incitation à éviter le dopage.

Present levels of training loads--which can exceed thirty hours a week for high level sportsmen--expose to overwork then to overtraining syndrome and finally to temptation of doping. At the same time testing techniques improve, particularly exercise tests with a linearly increasing load, and the follow-up of training effects on physical fitness provides more accurate data. The specialized literature has developed the notions of cardiac frequency reserve and of oxygen intake reserve within the last ten years. These notions, as those of produced power reserve, were applied here to assess the ventilatory threshold of 104 sportsmen (51 cyclists with high endurance and 53 team sportsmen with lower endurance) and of 223 sedentary witnesses. They allow, when completed with absolute level of aerobic endurance, to appreciate physical fitness of sportsmen all along sports season, to predict their capabilities to progress by an increase of training load or to reinforce the hypothesis of an over-working onset.

[The rehabilitation of chronic respiratory insufficiency]. / La rééducation-rédaptation des insuffisants respiratoires chroniques.

Respiratory rehabilitation is defined as a medical practice including a multidisciplinary medical program fitting each individual. Personalized retraining by means of exercises, is the master part of it, its aim is to improve the physical fitness in specialised institution then to maintain it when he becomes an out patient. In both cases, this retraining complies with strict rules concerning the mode of exercises (imposed power--duration of sessions--weekly frequency--progressiveness of overloading ...). This codification rests mainly on the recommendations of the American College of Sports Medicine. The choice of intensity at the beginning of the stay will be determined either by the maximal reserve of cardiac frequency or by the ventilatory threshold. This training has to involve extensive muscular mass and must not neglect the upper limbs. Ventilatory physiotherapy also plays an important part. The other components of rehabilitation concern optimisation of bronchodilator treatment, cessation of smoking, health education, physical education and relaxation, appraisal of nutritional status, assessment of therapeutic programs, of the quality of life and a long-term program for reinforcement of acquisitions. The therapeutic programs improve ventilatory performance, maximal oxygen intake, maximal tolerated power and quality of life. An adaptation of the St. George's Respiratory Questionnaire to patients hosted at the TOKI EDER Medical Center points out that the quality of life of patients with chronic respiratory failure is improved very highly significantly by this rehabilitation.

Acoustic properties of the normal chest.

Laënnec invented the stethoscope in 1816 and published a treatise on auscultation in 1819. We then had to wait until the 1950s to observe development of modern devices and methods of recording and signal-processing, which allowed objective studies of lung sounds in time and frequency fields. Tracheobronchial sounds generated by ventilation originate in the upper airways, the frequency content of these sounds has led to extensive research. Consolidated lungs act as more efficient sound conductors to the chest wall (bronchial breathing murmur). Tracheobronchial sounds contain higher frequency components compared to vesicular lung sounds. The origin of vesicular lung sounds has been becoming progressively clear for about 10 yrs. It is at least partly produced locally, deep, and probably intralobular. Clearly, further studies need to be performed in order to elucidate the true mechanisms involved in generating vesicular lung sounds, the redistribution of intrapulmonary gas or vibrations caused by the stretching of lung tissue. The devices developed are already useful for monitoring the state of patients in intensive care. Sooner or later, real time analysis and automated diagnosis will become available.

[The value of respiratory function tests in the surveillance of asthmatic children]. / Intérêt de l'exploration fonctionnelle respiratoire dans la surveillance des enfants asthmatiques.

The purpose of pulmonary function testing in children with asthma is to search for obstructive airway disease. We examined the charts of 169 asthmatic children during intervals between acute exacerbations. The severity of asthma was determined according to VIALATTE classification, with the Tiffeneau ration FEV1/VC (1) and the MMFR/VC ratio serving as obstructive indices. According to these data, children were classified into three groups: normal children (normal FEV1/VC and MMFR/VC), children with probable obstruction of the distal airways (normal FEV1/VC and decreased MMFR/VC), and children with both proximal and distal airway obstruction (decreased FEV1/VC and MMFR/VC). Since suggested normal values vary in the literature, we compared FEV1 and MMFR to determine as accurately as possible the number of children with obstructive disease. The relationship between the degree of clinical involvement and pulmonary function testing results was studied. Clinically, asymptomatic children with suspected normal respiratory function had evidence of obstructive disease in two out of three cases, and would benefit from drug therapy.

[Characterization and quantification by impulse analysis of sugar regulation disorders in man]. / Caractérisation et quantification par analyse impulsionnelle des troubles de la glyco-régulation chez l'homme.

Proposed model offers three transfer functions answering to a second order hypothesis and allowing to study separately blood sugar evolution and insulin release or synthesis functions by cell B. The model separates subjects in several classes (normals, chemical diabetes and patent insulin-dependent or independent diabetes) and quantifies treatment efficiency by its effects on blood sugar regulation.

Kinematics of spontaneous breathing: the ventilatory system as a non-linear oscillator.

The kinematics of spontaneous breathing at rest and during moderate exercise is described exactly by a non-linear differential equation, the parameters of which are determined by observation with a pneumotachograph. Analogue circuits are used for the determination of the coefficients and for the comparison by superimposition of the actual spirogram with its simulation. The ventilatory system, taken as a whole and without any assumption concerning its structure, works as a non-linear oscillator. If the classical distinction between a passive and an active ventilatory system is accepted, the concept of a linear equivalent of a non-linear oscillator is valid for the description of the properties of the passive system. It affords some of the advantages of linear mechanics and indicates the restrictions put upon the use of a linear hypothesis. The role of the different terms in determining the pattern of breathing is displayed and the correlation of scale factors with body size is shown. The physiological meaning of the components of muscle action is discussed.