Cinétique de la consommation d’oxygène chez le cycliste amateur

Aims

Study was to analyze the relationship between oxygen uptake and power output in amateur cyclists before and after threshold corresponding to a blood lactate concentration of 4 mmol/l.

Methods

We evaluated 109 subjects and they were divided according to age, cycling speciality, level and period. Each subject performed an incremental exercise test (50 W per 3 min) until exhaustion on an electromagnetically braked cycloergometer. Gas exchange data were continuously analyzed and recorded using an automated breath by breath system. Mean values of oxygen uptake were taken during the last minute of each stage in order to build and calculate the regression equations.

Results

The total sample presents an oxygen–kinetic deflection after lactate threshold, with the slope before threshold significantly higher (P < 0.001) than the slope after threshold. This indicates an absence of linearity. Considering the level, the slope and intercept before threshold of the national group presented significantly lower values than regional cyclists. For speciality, the slope before threshold is significantly lower in mountain bike group compared to road. Slope's analyse before and after lactate threshold could present complementary criteria for a good discrimination in comparison with classic concepts used during an incremental exhaustive test.     

Effets d'une restriction hydrique et alimentaire prolongée (ramadan) sur la performance et les réponses cardiovasculaires au cours d'un exercice incrémental en milieu tropical chaud

Backgroung

Previous studies showed that maximal oxygen uptake and maximal heart rate were not different during prolonged fasting (ramadan) compared to normal feeding period. However, the effect of ramadan on the blood pressure response during incremental exercise has not been investigated.

Objective

This study aimed to evaluate the evolution of blood pressure during incremental trial in ramadan period.

Methods

Twelve young trained male aged 24 ± 4 yrs participated as voluntary subjects. Their anthropometric parameters, maximal aerobic power and maximal heart were measured in fasting and in normal feeding periods during incremental trial on cycle ergometer.

Results

No significant difference was observed in any anthropometric parameter. Maximal aerobic power of fasting period was significantly less (P < 0,05) compared to normal feeding. Heart rate at rest, at maximal exercise and during a 15 min period of recovery was not significantly affected. Systolic blood pressure of fasting period at maximal power was significantly lower than during the control period (P < 0,05).

Conclusion

Ramadan negatively influences the capacity of maximal power and cardiovascular response at maximal power.     

Effets d’un exercice de type anaérobie sur le statut antioxydant enzymatique au cours de la récupération chez les judokas

Aim

To evaluate the effect of the anaerobic exercise on the enzymatic antioxidant statute in judokas’ regional level, because the effects of anaerobic exercise on the free radicals and antioxidants are relatively rare and have some divergences.

Materials and methods

We made this study on ten male judokas (age = 18.1 ± 1.6 years; weight = 77.2 ± 11.6 kg; height = 176.4 ± 4.6 cm), which carried out 30 seconds anaerobic capacity test (Wingate test). Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the Wingate test (P0) then five minutes later (P5), 10 minutes later (P10) then 20 minutes later (P20). The measured parameters are: the superoxide dismutase (SOD), the glutathion peroxidase (GPx) and the total antioxidant statute (SAT).

Results

The concentration of the SOD increases significantly (p < 0.05) at (P0); and regains the baseline values at (P20). The concentration of GPx increases significantly (p < 0.05) in (P0); in (P10) GPx reaches the baseline values. No significant effect of the anaerobic exercise was observed on the concentration of the SAT. Positive correlation was observed between the SOD and GPx to p < 0.05.

Conclusion

The anaerobic exercise modifies the activity of the antioxidant enzymes with different kinetics.     

30-15 Intermittent Fitness Test et répétition de sprints

Introduction

The maximal running velocity (V_IFT) reached at the end of the 30-15 Intermittent Fitness Tests (30-15_IFT) is very well related to most physiologic determinants of team-sport performance: explosive power of lower limbs, speed, maximal aerobic power and the ability to recover between exercise bouts. Nevertheless, its relationship with repeated sprint ability (RSA) was unknown.

Synthesis of the facts

Present results in 84 team-sport athletes show that V_IFT is very well related to mean sprint time during a RSA test (p > 0.001).

Conclusion

We conclude that V_IFT is highly representative of most physiologic determinants of performance in team-sports, and could thus been used to monitor athletic performance of team-sport players.     

Relation entre la puissance et la raideur musculotendineuse chez les sportifs de haut niveau

Goal

The aim of this study was to test the relation between the reactive power and the stiffness of the legs in high trained athletes (sprinters and skiing racers).

Method

A simple method to measure, in field conditions, the leg stiffness during maximal bouncing was used on twenty-eight sprinters, and twenty-nine skiing racers. In addition, the mechanical power called reactive power was calculated according to the method proposed by Bosco. The relationship between stiffness and power was observed in the different groups.

Results

The value of stiffness obtained was 29,866 ± 7372 N.m⁻¹. The power was equal to 52.33 ± 8,72 W.kg⁻¹. The main result of this study was that a relation between stiffness and power was obtained only in the sprinters (r² = 0,68, P < 0,001). This result stressed the influence of the sport speciality on the stiffness control.

Conclusion

The power measured during maximal bouncing, called reactive power is correlated with the leg's stiffness when subjects are trained to produce power in similar conditions. No correlation was obtained in skiing racers. The stiffness measurement was then a complementary test in the physical evaluation of the athletes.     

Application du concept de puissance critique à différentes populations

Aim

The aim of this review was to state the use of critical power concept at different populations and to summarize studies reported data in order to highlight its interest for the aerobic abilities assessement.

Conclusion

The critical power determination is based on times to exhaustion at different exercise intensities. The synthesis of several studies showed that this concept allows to discriminate populations relatively to their aerobic abilities. This is confirmed by its correlation to maximal oxygen uptake and ventilatory threshold in age and fitness different populations.     

Présentation clinique,biologique et ergométrique de six cas d’overtraining syndrome

Introduction

This work aimed at describing clinical and laboratory characteristics of the overtraining syndrome in its chronic form (staleness).

Summary of facts

We present six cases of chronic overtraining syndrome that have undergone an in-depth survey. Response to the standardized questionnaire for overtraining of the SFMS appears remarkably monomorphic. Patients often exhibit low IGFBP-3 and lower maximal heart rate at exercise, as well as low value of the constant γ2 of postexercice lactate decrease and a lowered ability to oxidize fat during exercise.

Conclusion

Clinical and biological presentation of the overtraining syndrome is highly variable, but the SFMS questionnaire is actually the most relevant approach. Decreases in IGFBP-3 and maximal heart rate are found in agreement with previous literature. A lowered γ2 constant and a “glucodependance” at exercise calorimetry may represent new interesting markers.     

Puissance critique de l’enfant prépubère et de l’adulte

Aim

The aim of the study was to compare aerobic and anerobic abilities of prepubertal children and adults with the critical power concept.

Methods

Sixteen children (10.3 ± 0.9 years) and 15 adults (23.5 ± 3.6 years) performed five tests: a maximal-graded test and four constant load exercises until exhaustion. Critical power (CP) and anaerobic-work capacity (CTA) were determined from the power-1/time (P-t) linear relationship.

Results

Determination coefficients for P-t were 0.94 ± 0.05 in children and 0.96 ± 0.04 in adults. PC values were significantly (p < 0.01) lower in children (2.7 ± 0.4 W/kg) than in adults (3.1 ± 0.3 W/kg). CTA values were significantly (p < 0.001) lower in children (136.4 ± 50.8 J/kg) than in adults (247.1 ± 45.7 J/kg).

Conclusion

Satisfying determination coefficients for CP and CTA were found in children and adults. Children have a lower CP and CTA than adults. This result is in accordance with literature.     

Extension du modèle puissance–temps limite pour estimer la production d’énergie aérobie et anaérobie lors de l’exercice intense

Aim

Examine how the modelling of the relation between power and time to exhaustion can provide an estimation of the production of aerobic and anaerobic energy during intense exercise.

Current knowledge

The hyperbolic model made it possible to define the critical power corresponding to the maximal rate of energy renewed by aerobic metabolism. A new model distinguishing the critical power from the maximal aerobic power has been built to estimate more precisely the anaerobic contribution. Data from middle distance runners and subjects tested on cycle ergometer showed a relative contribution of anaerobic metabolism arising from critical power and increasing until around 10 % of total power when aerobic energy production reaches its maximum.

Prospects

Considering the slow component of oxygen uptake would provide a more precise analysis of energy production and transformation during exercise at high intensity.     

Short term salbutamol ingestion and supramaximal exercise in healthy women

Objective

To test the hypothesis that chronic salbutamol intake improves performance during supramaximal exercise and to estimate the effects of this treatment on body composition, bone mass, and metabolic indices in healthy women.

Methods

Fourteen female volunteers (seven sedentary and seven recreationally trained) performed a 30 second Wingate test with and without salbutamol ingestion (12 mg/day for four weeks) in a random, double blind, crossover design. Blood samples were collected at rest, at the end of the test, and during passive recovery for lactate measurement. Body composition and bone mass were determined by dual energy x ray absorptiometry.

Results

Peak power appeared significantly earlier and was significantly (p<0.05) increased after salbutamol intake in all subjects. There was no difference in total work performed and fatigue indices with salbutamol compared with placebo. No significant alterations in lean or fat body mass and bone variables were observed with salbutamol treatment in either trained or untrained subjects during the trial. In contrast, blood lactate was significantly (p<0.05) increased during the recovery period after salbutamol ingestion compared with placebo.

Conclusion

As in men, chronic administration of therapeutic concentrations of salbutamol did not induce an anabolic effect in women but increased maximal anaerobic power. Further studies are necessary to clarify the mechanisms involved.     

Évolution des paramètres physique et anthropométrique de jeunes rugbymen de haut niveau sur une saison sportive

Introduction

The objective of the study is to measure the evolution of the anthropometric and physical parameters in young elite rugby players during one rugby league season.

Results

This study shows an enhancement of the aerobic and lactic anaerobic performances in the first six months of the preparation. Therefore, these aptitudes decrease in April. There is no modification of the lactic anaerobic performance during the season.

Conclusion

This study shows the difficulty to organise the training planification during the winter period for the elite players. The reason for the rugby league season fatigue has yet to be defined and will be the purpose of a future study.     

Clasificación y características del cáncer de intervalo en el programa de detección precoz de cáncer de mama en el Principado de Asturias

Objective

To review and classify the interval cancers found in the Principality of Asturias's Breast Cancer Screening Program (PDPCM). A secondary objective was to determine the histological characteristics, size, and stage of the interval cancers at the time of diagnosis.

Material and methods

We included the interval cancers in the PDPCM in the period 2003-2007. Interval cancers were classified according to the breast cancer screening program protocol, with double reading without consensus, without blinding, with arbitration. Mammograms were interpreted by 10 radiologists in the PDPCM.

Results

A total of 33.7% of the interval cancers could not be classified; of the interval cancers that could be classified, 40.67% were labeled true interval cancers, 31.4% were labeled false negatives on screening, 23.7% had minimal signs, and 4.23% were considered occult. A total of 70% of the interval cancers were diagnosed in the year of the period between screening examinations and 71.7% were diagnosed after subsequent screening. A total of 76.9% were invasive ductal carcinomas, 61.1% were stage II when detected, and 78.7% were larger than 10 mm when detected.

Conclusions

The rate of interval cancers and the rate of false negatives in the PDPCM are higher than those recommended in the European guidelines. Interval cancers are diagnosed later than the tumors detected at screening. Studying interval cancers provides significant training for the radiologists in the PDPCM.     

Prenatal MR imaging of Dandy-Walker complex: midline sagittal area analysis

Objective

To measure the mid-sagittal areas of vermis (VA) and of posterior fossa (PFA) and determine their differences among fetuses with various Dandy-Walker (DW) entities and control subjects.

Methods

We reviewed data in 25 fetal patients with a MR diagnosis of DW complex including hypoplastic vermis (HV), HV with rotation (HVR), and mega cistern magna (MCM), and in 85 fetal controls with normal CNS. PFA and VA of each subject were manually traced on mid-sagittal MR images. Regarding each of VA and PFA, after age correction, we determined statistically significant differences among HVR, HV, MCM, and control groups.

Results

The mean VA residue of MCM was greater than that of the control, which was in turn greater than those of HVR and HV. The mean PF residue of the control was smaller than all other groups.

Conclusion

Fetuses with HVR or HV had smaller VA than fetuses with MCM or control subjects. Fetuses with MCM, HVR, or HV had larger PFA than control subjects. These results may be an early step leading to better understanding of the confusion about the PF anomalies in future.     

Analyse de variables permettant la détermination du niveau d'un cycliste

Aims

We aimed to define a mathematical model allowing to foresee the level of a cyclist.

Methods

One hundred (and) six cyclists were classified according to their level and some of their physiological characteristics were measured with the threshold (4 mmol of lactate) and with the maximum values of their oxygen flow.

Results

To the threshold, power, lactatemy, age and size allow to foresee the level with an error rate of 27% ; to the maximum values, the criteria are development, flow in oxygen, lactatemy and age (error rate of 31%).

Conclusion

These results indicate that our mathematical model allows to envisage the level.     

Contribution à l’étude des effets d’un programme de réentraînement à l’effort sur les aptitudes physiques de patients atteints de bronchopneumopathie chronique obstructive

Aims

The purpose of this study was to evaluate the effect of a three-months’ training rehabilitation on the physical capacity of patients suffering from chronic obstructive pulmonary disease (COPD).

Methods

The aerobic and anaereobic capacity was evaluated in 36 patients (Stage 2) before and after a training rehabilitation period: (duration: three months, frequency: two sessions per week, intensity: 65% of aerobic threshold for 25 min, type: regular exercise on a bicycle).

Results

Training rehabilitation caused a statistically significant specific improvement of submaximal aerobic capacity and an increase of quadriceps and flexor of the fingers’ strength.     

Comparaison des paramètres de la relation puissance–temps limite obtenus par différents modèles de la puissance critique

Introduction

The aim of this study was to determine how the choice of the model would affect the estimation of the parameters of the relation between power and limit time.

Synthesis of facts

Twelve volunteers have done five or six time trials on cycle ergometer making it possible to test six models: two linear forms (Lin-W et Lin-P) and one non-linear form (Nlin-2) of the simple hyperbolic model, two models with a finite limit for maximal power (Nlin-3 et EXP) and one model which distinguished the critical power and the maximal aerobic power (Mod-α). Lin-P and EXP have given the highest estimates for the critical power and Nlin-3 the lowest. No statistical difference was observed between the estimates from Lin-W, Nlin-2 and Mod-α.

Conclusion

Although Nlin-2 was better on the statistical ground and Mod-α could give more information on the anaerobic contribution according to the total power, Lin-W would be a robust method to estimate the critical power.     

Técnicas de recanalización vertebrobasilar antes de la introducción de las endoprótesis recuperadoras: la reapertura no es sinónimo de buena evolución

Objectives

To evaluate the recanalization rate and clinical outcome three months after endovascular treatment for vertebrobasilar occlusion before the placement of stentrievers.

Material and methods

We reviewed all cases of basilar thrombosis treated with endovascular techniques at our center. We reviewed the clinical outcomes with the main objective of determining the recanalization rate and the secondary objective of evaluating the outcome using the modified Rankin scale (mRS) three months after treatment. We assessed clinical and angiographic variables and correlated them with outcome and complications.

Results

We reviewed a total of 27 consecutive patients (mean age, 58.1 ± 15.5 y; median National Institutes of Health Stroke Scale (NIHSS), 21, interquartile range, 18-29; median Glasgow coma score (GCS) 7, interquartile range, 4-9.5). The mean time between the onset of symptoms and endovascular treatment was 26.3 ± 41.7 hours. Complete or partial recanalization was achieved in 23 (85.1%) patients. Three months after treatment, 16 (59.2%) had died and 6 (22.2%) had good outcome (mRS ≤ 2).

Conclusion

Endovascular treatment achieved a high rate of recanalization of occlusions of the basilar artery. Nevertheless, a high percentage of the patients did not have a good outcome. New materials might improve the prognosis in these patients.     

Effet du port d'une combinaison intégrale et d'une trifonction sur la vitesse de nage et l'amplitude du cycle de bras en triathlon

Introduction

The purpose of this study was to compare the influence of complete wetsuit and tri-function on the swimming speed and arm stroke characteristics in crawl by triathletes.

Synthesis

Seven triathletes have executed three randomised trials of 400 m front crawl at maximal intensity: without wetsuit, complete wetsuit and tri-function.

Conclusion

Results pointed out that the complete suit allows a significant improvement of the performance and of the distance per cycle by report the swimming with a tri-function.