Frédéric Lemaître

Frédéric Lemaître
Université de Rouen | UR · UFR Sciences du Sport et Éducation Physique

PhD, HDR

About

107
Publications
49,890
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1,188
Citations
Additional affiliations
September 2002 - September 2014
Université de Rouen
Position
  • Professor (Assistant)
September 1998 - June 2001
Université Clermont Auvergne
Position
  • Lecturer

Publications

Publications (107)
Article
Full-text available
Repeated apneas are associated with severe hypoxemia that may ultimately lead to loss of consciousness in some breath-hold divers. Despite increasing number of practitioners, the relationship between apnea-induced hypoxia and neurocognitive functions is still poorly understood in the sport of free diving. To shed light onto this phenomenon, we exam...
Article
Full-text available
PurposeThe study aims to investigate the effects of moderate intermittent hypoxia (IH) on key cardio-metabolic risk factors in overweight and obese subjects. Methods Six subjects were exposed to 10 sessions of moderate IH over 2 weeks (based on \( \overline{SpO_2}=80\% \); ~70 min per session). Measures were made of blood glucose (GLU) and lactate...
Article
Full-text available
The trigeminocardiac reflex (TCR) has previously been described in the literature as a reflexive response of bradycardia, hypotension, and gastric hypermotility seen upon mechanical stimulation in the distribution of the trigeminal nerve. The diving reflex (DR) in humans is characterized by breath-holding, slowing of the heart rate, reduction of li...
Article
Full-text available
Although it has been demonstrated that the exponential decay model fits the heart rate (HR) kinetics in short static breath holding (BH), this model might be inaccurate when BH is maintained for several minutes. The aim of this study was to build a new meaningful model to quantify HR kinetics during prolonged static BH. Nonlinear regression analysi...
Article
Full-text available
Nitrogen (N 2 ) accumulation in the blood and tissues can occur due to breath-hold (BH) diving. Post-dive venous gas emboli have been documented in commercial BH divers (Ama) after repetitive dives with short surface intervals. Hence, BH diving can theoretically cause decompression illness (DCI). “Taravana,” the diving syndrome described in Polynes...
Article
Full-text available
Breath-hold diving involves environmental challenges, such as water immersion, hydrostatic pressure, and asphyxia, that put the respiratory system under stress. While training and inherent individual factors may increase tolerance to these challenges, the limits of human respiratory physiology will be reached quickly during deep breath-hold dives....
Article
Full-text available
Decompression illness (DCI) is well known in compressed-air diving but has been considered anecdotal in breath-hold divers. Nonetheless, reported cases and field studies of the Japanese Ama, commercial or professional breath-hold divers, support DCI as a clinical entity. Clinical characteristics of DCI in Ama divers mainly suggest neurological invo...
Article
Full-text available
The trigeminocardiac reflex (TCR) is a well-recognized brainstem reflex that represents a unique interaction between the brain and the heart through the Vth and Xth cranial nerves and brainstem nuclei. The TCR has mainly been reported as an intraoperative phenomenon causing cardiovascular changes during skull-base surgeries. However, it is now appr...
Article
The aim of this study was to investigate the impact of breath-hold diving strategies regarding loss of consciousness (LOC). Three international competitions were examined through video in constant weight diving with (CWT) or without (CNF) fins. We analysed three breath-hold parameters (time, speed, and movements count) for the following phases: act...
Article
Eight well-trained male cyclists participated in two testing sessions each including two sets of 10 cycle exercise bouts at 150% of maximal aerobic power. In the first session, subjects performed the exercise bouts with end-expiratory breath holding (EEBH) of maximal duration. Each exercise bout started at the onset of EEBH and ended at its release...
Article
Diving accident in breath-hold (BH) divers (Ama) is a stroke-like neurological condition involving the brain. Ama divers are at a risk of ischemic brain injuries which are situated in watershed or terminal zones of cerebral arteries, and/or corticomedullary junctional area of cerebral arteries. The underlying mechanisms of brain damage in BH diving...
Article
Full-text available
This study investigated the impact of repeated-sprint (RS) training with voluntary hypoventilation at low lung volume (VHL) on RS ability (RSA) and on performance in a 30-15 intermittent fitness test (30-15IFT). Over 4 weeks, 17 basketball players included eight sessions of straight-line running RS and RS with changes of direction into their usual...
Article
Breath-hold divers are known to develop cardiac autonomic changes and brady-arrthymias during prolonged breath-holding (BH). The effects of BH-induced hypoxemia were investigated upon both cardiac autonomic status and arrhythmogenesis by comparing breath-hold divers (BHDs) to non-divers (NDs). Eighteen participants (9 BHDs, 9 NDs) performed a maxim...
Book
Full-text available
This book covers the historical, physiological, pathological, psychological and practical aspects of apnea. Freediving. From theory to practice is therefore intended for all those interested in this field: experienced freedivers or beginners looking for documentation, future apnea or spearfishing instructors, coaches and doctors in charge of sports...
Article
Full-text available
This short review focuses on pulmonary injury in breath-hold (BH) divers. When practicing their extreme leisure sport, they are exposed to increased pressure on pulmonary gas volumes, hypoxia, and increased partial gas pressures. Increasing ambient pressures do present a serious problem to BH deep divers, because the semi-rigid thorax prevents the...
Article
Full-text available
PurposeThe aim of this pilot study was to assess the impact of a physical activity program of walking 10,000 steps per day along with monthly dietary counseling on the body composition, biological parameters, resting energy expenditure (REE) and health-related quality of life (HRQoL) of obese individuals. Methods Thirty-five obese adults (26 women;...
Article
We investigated the oxygen-conserving potential of the human diving response by comparing trained breath-hold divers (BHDs) to non-divers (NDs) during simulated dynamic breath-holding (BH). Changes in haemodynamics [heart rate (HR), stroke volume (SV), cardiac output (CO)] and peripheral muscle oxygenation [oxyhaemoglobin ([HbO2]), deoxyhaemoglobin...
Article
Introduction: The South Pacific has a high prevalence of obesity and super-obesity. We reviewed our experience with laparoscopic sleeve gastrectomy (LSG) to evaluate its efficacy and safety. Methods: A retrospective review of a prospectively collected database of LSGs carried out by one surgeon in one center. The percentage of excess weight loss...
Chapter
Full-text available
The trigeminocardiac reflex (TCR) has been described in the literature as a reflexive response of bradycardia, hypotension, and gastric hypermotility seen upon predominantly mechanical, but also thermic stimulation in the distribution of the trigeminal nerve. The diving reflex (DR) in humans is initiated upon holding the breath (breath holding) and...
Article
Full-text available
Purpose: The aims were to: (1) compare peak oxygen uptake ([Formula: see text]peak) predicted from four standard equations to actual [Formula: see text]peak measured from a cardiopulmonary exercise test (CPET) in obese patients with metabolic syndrome (MetS), and (2) develop a new equation to accurately estimate [Formula: see text]peak in obese wo...
Research
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Interview pour un article paru dans la revue Science et vie Junior en 2013
Research
Full-text available
Article traduit de Wilderness Environ Med 2014; 25: 258-262 en Japonais
Conference Paper
Full-text available
Article
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Ischaemia-modified albumin (IMA) is a marker of the release of reactive oxygen species (ROS) during hypoxaemia. In elite divers, breath-hold induces ROS production. Our aim was to evaluate the kinetics of IMA serum levels during apnea. Twenty breath-hold divers were instructed to perform a submaximal static breath-hold. Twenty non-diver subjects se...
Article
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Article
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Abstract The aims of this study were to test the reproducibility of the 6-minute stepper test (6MST), and evaluate its accuracy in detecting improved functional capacity after pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD). Thirty-five COPD outpatients performed two 6MSTs in the same session, before (6MS...
Article
Full-text available
Purpose We assessed the validity of predicting peak oxygen uptake (\( {\dot{V}} \)O2 peak) from the relationship between oxygen uptake (\( {\dot{V}} \)O2) and overall ratings of perceived exertion (RPE) obtained during the initial stages of a cardiopulmonary exercise test (CPET). Method Fifteen healthy participants and 18 patients with chronic o...
Article
Full-text available
Background Acute decompression illness (DCI) involving the brain (Cerebral DCI) is one of the most serious forms of diving-related injuries which may leave residual brain damage. Cerebral DCI occurs in compressed air and in breath-hold divers, likewise. We conducted this study to investigate whether long-term breath-hold divers who may be exposed t...
Article
Full-text available
Objective: Symptoms consistent with neurological decompression sickness (DCS) in commercial breath-hold (Ama) divers has been reported from a few districts of Japan. The aim of this study was to detect circulating intravascular bubbles after repetitive breath-hold diving in a local area where DCS has been reported in Ama divers. Methods: The par...
Data
Full-text available
tTrained breath-hold divers (BHDs) are exposed to repeated bouts of intermittent hypoxia and hyper-capnia during prolonged breath-holding. It has thus been hypothesized that their specific training maydevelop enhanced chemo-responsiveness to hypoxia associated with reduced ventilatory response tohypercapnia.Hypercapnic ventilatory responses (HCVR)...
Article
Full-text available
Background: Morbid obesity prevalence is rapidly increasing among adolescents worldwide. Evidence is mounting that bariatric surgery is the only reliable method for substantial and sustainable weight loss; however, the debate continues with regard to the optimal surgical procedure for adolescents and to the age limit when bariatric surgery should...
Article
Trained breath-hold divers (BHDs) are exposed to repeated bouts of intermittent hypoxia and hypercapnia during prolonged breath-holding. It has thus been hypothesized that their specific training may develop enhanced chemo-responsiveness to hypoxia associated with reduced ventilatory response to hypercapnia. Hypercapnic ventilatory responses (HCVR)...
Article
Full-text available
While some studies have demonstrated that respiratory muscle endurance training (RMET) improves performances during various exercise modalities, controversy continues about the transfer of RMET effects to swimming performance. The objective of this study was to analyze the added effects of respiratory muscle endurance training (RMET; normocapnic hy...
Article
Full-text available
Voluntary breath-holding (BH) elicits several hemodynamic changes, but little is known about maximal static immersed-body BH. We hypothesized that the diving reflex would be strengthened with body immersion and would spare more oxygen than maximal dry static BH, resulting in a longer BH duration. Eleven trained breath-hold divers (BHDs) performed a...
Article
Full-text available
The cardiac diving response, 12-lead electrocardiogram (ECG) and the prevalence, time of onset, and possible associations of cardiac arrhythmias were examined during deep breath-hold (BH) dives. Nine elite BH divers (33.2 +/- 3.6 years; mean +/- SD) performed one constant-weight dive of at least 75% of their best personal performance (70 +/- 7 mete...
Article
The graded exercise test (GXT) is used to measure the exercise capacity of patients with chronic obstructive pulmonary disease (COPD). To do this GXT must be maximal (exhaustive). However, the value of the blood lactate at the GXT endpoint [La(-)max] or after a recovery period of three minutes [La(-)recovery], to confirm that the GXT is maximal, re...
Article
Introduction The graded exercise test (GXT) is used to measure the exercise capacity of patients with chronic obstructive pulmonary disease (COPD). To do this GXT must be maximal (exhaustive). However, the value of the blood lactate at the GXT endpoint [La−max] or after a recovery period of three minutes [La−recovery], to confirm that the GXT is ma...
Article
Full-text available
The ability to predict performance is of great interest for athletes and coaches. It is helpful for the selection of athletes to a team, the prescription of individualized training and the determination of the optimal pacing strategy. However, it is often difficult to judge the time to exhaustion without maximal exercise testing, which is often dif...
Article
The most common tool used for measuring effort perception is the rating scale of perceived exertion (RPE) developed by Borg. This scale is also used for various outcomes in the general population. The validity and reliability of this scale have already been reported in obese patients. However, the relevance of measuring perceived exertion in obese...
Article
Full-text available
The ability to predict performance is of great interest for athletes and coaches. It is helpful for the selection of athletes to a team, the prescription of individualized training and the determination of the optimal pacing strategy. However, it is often difficult to judge the time to exhaustion without maximal exercise testing, which is often dif...
Article
Full-text available
Habituellement, il est recommandé de prescrire une intensité d’exercice initiale comprise entre 40 et 60 % de la consommation pic d’oxygène (VO2pic) chez les sujets ayant une faible condition physique. D’un point de vue pratique, d’autres auteurs préfèrent utiliser un pourcentage de la fréquence cardiaque de réserve (FCréserve), ou une valeur de pe...
Article
Il est habituellement admis que la perception de l’effort (RPE) peut être utilisée en association à des variables physiologiques pour affirmer la maximalité d’une épreuve d’effort. Certains auteurs considèrent qu’une valeur de RPE = 18 est un critère subjectif de maximalité. L’objectif de cette étude est donc d’examiner si les valeurs de RPE peuven...
Article
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L’activité physique (AP) a des effets bénéfiques sur l’obésité. Pourtant, les patients obèses adhèrent peu aux programmes d’AP en partie à cause de la monotonie des exercices continus (EC) proposés. Pour pallier cela, des exercices intermittents (EI) peuvent être prescrits. L’objectif de cette étude est de déterminer l’exercice (EC vs EI) le mieux...
Article
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Les exercices intermittents (EI), ont des effets bénéfiques sur l’obésité. D’un autre côté, il est reconnu que plus un patient obèse a un indice de masse corporelle (IMC) élevé, plus sa condition physique est faible. L’objectif de cette étude est donc d’examiner la possible influence du degré d’obésité (obésité modérée : 30 = IMC < 35 kg/m2, sévère...
Article
Full-text available
Le but de cette étude est d’analyser, chez des sujets obèses, l’effet d’un suivi diététique associé à la réalisation de 10 000 pas par jour sur la qualité de vie, les paramètres anthropométriques et la dépense énergétique de repos.Patients et méthodesSoixante neuf sédentaires obèses ont suivi pendant 6 mois un programme combinant un suivi diététiqu...
Article
Full-text available
This study examined the effects of an exercise training program on ventilatory function at rest and the exercise cardiorespiratory pattern in relation to body composition in obese individuals (53.4±7.6 years; 158.6±6.7 cm). After initial tests (exercise testing and anthropometric assessment), ten women participated in a 12-week training program com...