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The development of personalised training programmes is crucial in the management of obesity. We evaluated the ability of 2 heart rate variability analyses to determine ventilatory thresholds (VT) in obese adolescents. 20 adolescents (mean age 14.3 ± 1.6 years and body mass index z-score 4.2 ± 0.1) performed an incremental test to exhaustion before and after a 9-month multidisciplinary management programme. The first (VT1 ) and second (VT2 ) ventilatory thresholds were identified by the reference method (gas exchanges). We recorded RR intervals to estimate VT1 and VT2 from heart rate variability using time-domain analysis and time-varying spectral-domain analysis. The coefficient correlations between thresholds were higher with spectral- domain analysis compared to time-domain analysis: Heart rate at VT1 : r = 0.91 vs. = 0.66 and VT2 : r = 0.91 vs. = 0.66; power at VT1 : r = 0.91 vs. = 0.74 and VT2 : r = 0.93 vs. = 0.78; spectral-domain vs. time-domain analysis respectively). No systematic bias in heart rate at VT1 and VT2 with standard deviations < 6 bpm were found, confirming that spectral-domain analysis could replace the reference method for the detection of ventilatory thresholds. Furthermore, this technique is sensitive to rehabilitation and re-training, which underlines its utility in clinical practice. This inexpensive and non-invasive tool is promising for prescribing physical activity programs in obese adolescents. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to evaluate whether endurance exercise in middle-aged men induces changes in plasma total homocysteine (tHcy) and total cysteine (tCys), and whether these changes depend on the diet especially on vitamin B6, folic acid and vitamin B12 intakes. Methods: Twelve trained subjects (52.33 ± 2.4 years) and twelve untrained subjects (56.23 ± 0.9 years) volunteered for the present study. tHcy and tCys were measured with high-pressure liquid chromatography at rest in both groups and during an incremental exercise performed on a cycle ergometer until exhaustion in the trained subjects. Results: At baseline homocysteinemia and cysteinemia were lower in trained subjects (7.48 ± 0.4 and 183.45 ± 13.6 μmol/l) compared with untrained subjects (9.79 ± 0.4 μmol/l, p < 0.001; 229.01 ±14.7 μmol/l, p < 0.05, respectively). Incremental exercise also induced a decrease in tHcy and tCys concentrations. Moreover, tHcy concentration was negatively related to the folic acid and B12 intakes in untrained (r = –0.589, p < 0.05; r = –0.580, p < 0.05, respectively) as well as in trained groups (r = –0.709, p < 0.01; r = –0.731, p < 0.01, respectively) whereas no correlation between tCys and vitamin in the diet was observed. Conclusion: This study demonstrates that the combined effects of a chronic physical exercise and a high folate and vitamin B12 intake could be responsible for the reduction of plasma tHcy and tCys concentrations that might be a key for the prevention of many diseases. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Allergic rhinitis often occur at the same time with many upper and lower airway diseases in which there is asthma. Many patients without clinical asthma may have an asymptomatic bronchial hyperreactivity and an allergic rhinitis at the same time. An overview of these actual knowledges is done including clinical, respiratory functional explorations, therapeutic studies, as well as those observed in chronic nasal dysfunctions (allergic or non allergic eosinophilic rhinitis, nasal polyposis, chronic rhinitis).Objectives. – The aim of this study is to determine bronchial hyperresponsiveness of a chronic nasal dysfunction population having allergic or non allergic rhinitis.Material and methods. – Retrospective study of respiratory functional explorations (using a methacholine provocation test) among non asthmatic patients consulting for rhinology-allergy diseases but with broncho-pulmonary symptomatology.Results. – It has been observed an allergic rhinitis population without upper bronchial hyperreactivity but with a small airway obstruction revealed or worsened during the methacholine bronchoprovocation test.Conclusion. – Chronic nasal dysfunction and small airway obstruction are correlated. This association shows an airway inflammation from the nose through the small bronchi. As upper bronchial hyperreactivity can precede asthma, a small airway obstruction could precede a bronchial hyperreactivity. Nasal chronic dysfunction treatment could act upon small airway obstruction, or central bronchial hyperreactivity or asthma appearance. [Copyright &y& Elsevier]

The aim of this study was to determine the hormonal responses, which are dependent on the sleep wake cycle, to strenuous physical exercise. Exercise was performed after different nocturnal regimens: (i) a baseline night preceded by a habituation night; (ii) two nights of partial sleep deprivation caused by a delayed bedtime or by an early awakening; and (iii) two nights of sleep after administration of either a hypnotic compound (10 mg zolpidem) or a placebo. Eight well-trained male endurance athletes with a maximal oxygen uptake of 63.5 +/- 3.8 ml x kg(-1) x min(-1) (mean value +/- s(x)) were selected on the basis of their sleeping habits and their physical training. Polygraphic recordings of EEG showed that both nights with partial sleep loss led to a decrease (P< 0.01) in stage 2 and rapid eye movement sleep. A delayed bedtime also led to a decrease (P < 0.05) in stage 1 sleep. Zolpidem had no effect on the different stages of sleep. During the afternoon after an experimental night, exercise was performed on a cycle ergometer. After a 10-min warm-up, the participants performed 30 min steady-state cycling at 75% VO(2-max) followed by a progressively increased workload until exhaustion. The recovery period lasted 30 min. Plasma growth hormone, prolactin, cortisol, catecholamine and lactate concentrations were measured at rest, during exercise and after recovery. The concentration of plasma growth hormone and catecholamine were not affected by partial sleep deprivation, whereas that of plasma prolactin was higher (P < 0.05) during the trial after an early awakening. Plasma cortisol was lower (P < 0.05) during recovery after both sleep deprivation conditions. Blood lactate was higher (P < 0.05) during submaximal exercise performed after both a delayed bedtime and an early awakening. Zolpidem-induced sleep did not affect the hormonal and metabolic responses to subsequent exercise. Our results demonstrate only minor alterations in the hormonal responses to exercise after partial sleep deprivation.

Immersion is considered to facilitate exercise-based rehabilitation. However, the drag effect of moving limbs in water, likely to increase the respiratory requirements at exercise, is not mentioned in many reports. The energetic and ventilatory requirements of 30 min steady state cycling exercise performed by healthy male subjects in air and during immersion up to the xiphoid in 33 degrees C water were compared. In the first experimental series nine subjects exercised at the same 60% maximal oxygen consumption (V'O2,max) in air and water. In the two ambient conditions, ventilatory variables had similar values, but the ergometric setting had to be reduced during water immersion so that the workload rated only 69+/-20 W (mean+/-SD) in water versus 121+/-32 W (p<0.001) in air. In the second experimental series, the same ergometric work load (122 W) was achieved by nine subjects with an average V'O2 of 2,210+/-300 mL x min(-1) in air versus 2,868+/-268 mL x min(-1) in water (p<0.001). Resting water immersion caused a marked trend for decreasing vital capacity (p=0.06), but no modification of other ventilatory variables. During exercise at similar V'O2, the average values of minute ventilation (V'E), tidal volume (VT), respiratory frequency (fR), tidal inspiratory time (VT/tI) were not different between water and air. However, at similar ergometric workload, V'E, VT, fR, VT/tI and plasma lactate levels were significantly higher in water than in air. Such consequences of the drag effect of water upon limb movements have not been reported in previous studies relying on shorter exercise bouts. Thus, maintaining steady exercise levels in water either led to a decrease in the workload or required a 25% higher oxygen consumption than in air. These findings may be relevant to the prescription of water immersion rehabilitation programmes.

Since 15 years, the ASMT (Association for the promotion of sports in enterprises) has been trying to demonstrate that physical activities is a health factor for workers and their enterprises. Few studies (1980-1990) in individual enterprises (Alsthom, IBM, Aérospatiale, Peugeot...), and a national one (1985, 1,600 sportsmen) have shown the relationship between exercise and a lower absenteeism. These results were confirmed by a randomized national controlled study in 1990-1991. With the assistance of 115 work-doctors, the ASMT included more than 22,000 workers: 38% of them had physical activities (ASMT 1: 1 hour a week, ASMT 2: 3 hours a week, ASMT 3: competitors), and 62% had none. Exercisers have less industrial injuries than sedentary people (3.78% vs 4.52%. p. < 0.001) and less absences for illness (26.4% vs 30.8%. p. < 0.001). The duration of their absences are shorter for industrial injuries (sedentary people: 27.9 days, ASMT 1: 27.1 days, ASMT 2: 25.5 days, ASMT 3: 24.6 days) and for illness (sedentary people: 23.6 days, ASMT 1: 19.1 days, ASMT 2: 17.4 days, ASMT 3: 15.3 days).

The aim of this study was to examine the influence of water immersion to the chest on cardio-vascular adaptation to exercise. Upright or sitting immersion causes an increase in central blood volume, but it remains controversial whether central blood volume remains elevated during dynamic exercise in water and facilitates cardiac adaptation, depending particularly on the intensity of exercise which can be matched for O2 consumption (metabolic range) or for mechanical intensity (work load). We have compared hemodynamic variables measured during two cycling exercises at the same mechanical intensity, performed both in ambiant air and during immersion up to the chest.

The aim of the present study was to investigate the effects of a delayed bedtime (3 a.m.), an advanced rising (3 a.m.), a sleep under placebo and under a hypnotic compound, i.e. 10 mg of zolpidem (Stilnox) on sleep structure and on the adaptations to a subsequent exercise in 8 male athletes. The chronology of these nights was randomized and each treatment administered in a double blind fashion. During each experimental night, subjects were monitored with conventional EEG/EOG/EMG polygraphic recordings. The next day, athletic performance was tested using a bicycle ergometer. A codified exercise was performed and consisted to a 10 min warm up followed by a 30 min steady state cycling corresponding to 75% of predetermined VO2 max. Then the work load increased progressively by steps of 10 W every minute until exhaustion. The recovery lasted 30 min. Heart rate, ventilation, VO2, ERO2 were monitored during all exercise and recovery. Plasma lactates and catecholamines were also measured at the same time. The data concerning sleep recordings showed that both nights with partial sleep deprivation resulted in a drop of time spent in slow wave sleep II (decrease of 55%) and in rapid eye movement sleep (decrease of 45%) while the amount of slow wave sleep III and IV were identical to that observed after the reference night. The sleep onset latency and the amount of sleep in stage I was reduced only after the delayed bedtime. Sleep data under zolpidem did not show any significantly difference in the amount of different sleep stages.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to estimate the preoperative evaluation of the respiratory risk, a well adapted clinical examination associated with a routine pulmonary function test (VC, FEV1) can be sufficient. Although some patients with cardiopulmonary disorders or candidates to lung resection need more complex assessments: the flow-volume loop to detect small airways obstruction (MEF 50%, MEF 25%), measure of bronchial hyperreactivity to predict bronchospasm during anaesthesia, residual volume for the diagnosis of emphysema, diffusing capacity (DCO) to discover lung fibrosis: these parameters disruption always make the pronostic worse. It is also useful to couple together preoperative function test and pulmonary scintigraphy to predict post-operative values after lung resection. But, these criteria for operability are not always a good indicator of post-operative complications. So it is possible to use in addition the results of exercise testing to determine cardio-respiratory performances and maximal oxygen consumption (VO2MAX) which seem better correlated with mortality and post-operative lung surgical complications. Preliminary results of our study concerning thirty patients hospitalized in Besancon-St-Jacques Hospital, agree with the hypothesis that exercise testing is an important criterion in the pre-operative evaluation and to predict post-operative mortality and morbidity of patients candidates to thoracic surgery.

The changes in cardiac and ventilatory responses were measured in 7 endurance athletes during physical exercise on a bicycle ergometer, taking place after a control night and after a night with partial sleep deprivation in the middle of the night. The results show that, despite the maximal work load was not modified with control, heart rate, ventilation and VE/VO2 ratio (ERO2) were greater at the submaximal (75% of the VO2 max) and maximal work load and oxygen consumption decreased at maximal work, after the night of partial sleep deprivation as compared to the control. These findings suggest that acute sleep loss may contribute to alter the endurance performance by impairment of aerobic pathways.

Being little myelotoxic, Bleomycin (BLM) is more and more used in association with other anti-neoplastic drugs; its pulmonary toxicity is not to be overlooked and here is a recall of the risks of pulmonary fibrosis during treatment by BLM. This review is based on a personal experience of 45 cases, of which 6 were cases of respiratory insufficiency. It derived also from a study of the literature which expressed the frequency of respiratory accidents in figures varying from 2 to 94% according to the criteria of tolerance used by the authors. BLM toxicity for the pulmonary tract being important some precautions should be taken in its use: specially supervising aged patients or those with a pastpathological respiratory story; it should particularly concern the functional side, using CO ductance to trace the first signs of toxicity A total dose of 450 mg should not be exceeded.