Claude Robinet's research while affiliated with Aix-Marseille Université and other places

Publications (16)

Article
Full-text available
This experiment was designed to assess the effects of prolonged whole body immersion (WBI) in thermoneutral and cold conditions on plasma volume and hydromineral homeostasis.10 navy "combat swimmers" performed three static 6-h immersions at 34 degrees C (T34), 18 degrees C (T18) and 10 degrees C (T10). Rectal temperature, plasma volume (PV) changes...
Article
Full-text available
Thermoneutral water immersion increases cardiac preload and changes the neuroendocrine settings of blood volume regulation. The resulting marked diuresis may lead to significant haemodynamic changes after the end of a prolonged water immersion. Ten volunteers underwent 6 h of complete thermoneutral water immersion. Changes in cardiovascular status...
Article
Full-text available
We hypothesized that the changes in muscle temperature and interstitial pressure during thermoneutral immersion may affect the reflex adaptation of the motor drive during static contraction, assessed by the decrease in median frequency (MF) of electromyogram (EMG) power spectrum. Ten subjects were totally immersed for 6 h at 35 degrees C and repeat...
Article
The present study was designed to assess the cardiac changes induced by cold water immersion compared with dry conditions during a prolonged hyperbaric and hyperoxic exposure (ambient pressure between 1.6 and 3 ATA and PiO(2) between 1.2 and 2.8 ATA). Ten healthy volunteers were studied during a 6 h compression in a hyperbaric chamber with immersio...
Article
Full-text available
To evaluate the effects of a submaximal exercise performed 2 h before a simulated dive on bubble formation and to observe the haemodynamic changes and their influence on bubble formation. 16 trained divers were compressed in a hyperbaric chamber to 400 kPa for 30 min and decompressed at a rate of 100 kPa/min with a 9 min stop at 130 kPa (French Nav...
Article
The consequences of a prolonged total body immersion in cold water on the muscle function have not been documented yet, and they are the object of this French Navy research program. Ten elite divers were totally immerged and stayed immobile during 6 h in cold (18 and 10 degrees C) water. We measured the maximal voluntary leg extension (maximal volu...
Article
Full-text available
A single bout of aerobic exercise 24 h before a dive significantly reduces the formation of circulating venous gas emboli (VGE) on decompression. The purpose of this investigation was to determine the effect of aerobic exercise 2 h before a dive. There were 16 trained military divers who were compressed to 30 msw (400 kPa) for 30 min breathing air...
Article
Full-text available
In the present study, we observed the haemodynamic changes, using echocardiography and Doppler, in ten healthy volunteers during 6 h of compression in a hyperbaric chamber with a protocol designed to reproduce the conditions as near as possible to a real dive. Ambient pressure varied from 1.6 to 3 atm (1 atm=101.325 kPa) and partial pressure of ins...
Article
Full-text available
Many studies have described the physiology of water immersion (WI), whereas few have focused on post WI physiology, which faces the global water loss of the large WI diuresis. Therefore, we compared hemodynamics and vasomotor tone in 10 trained supine divers before and after two 6h sessions in dry (DY) and head out WI environments. During each expo...
Article
We compared the changes in compound muscle mass action potential (M-wave) recorded in vastus lateralis in response to hyperbaric hyperoxia (HBO) in nine combat divers who dived daily while breathing 100% O2 or O2-enriched mixture (O2 divers) to those measured in eight recreational divers who dived occasionally using compressed air/21% O2 (air diver...
Article
We studied surface electromyogram (SEMG) changes during 1-h endurance cycling in 12 healthy subjects of whom five were involved in mountain bike training programme. The work load was set at 50% of the predicted maximal heart rate. The surface EMG and the compound evoked muscle action potential (M-wave) from the vastus lateralis muscle were recorded...

Citations

... A negative inotropic effect of hyperoxia should also be considered. It has been demonstrated during exposure to normobaric hyperoxia [11,16,18,19]. However, the negative inotropic effect of oxygen generally does not persist during exposure to HH [20,21], as increased ambient pressure causes the elevation in cardiac contractility [8,22,23]. ...
... It is not true that after immersed cooling a subject is in a vasoplegic state. In fact the reduction in large cold-induced arterial and venous vasoconstrictive tone occurs over several hours (Robinet et al., 2006;Boussuges et al., 2009;Florian et al., 2013;Riera et al., 2014). Yes removing the squeezing effect of hydrostatic pressure precipitate rescue collapse (Lloyd, 1992). ...
... Heat treatment is usually illustrated by dilation effects and assistance of bloodstream outflow, although icy treatment is normally detailed by vasoconstriction and discomfort decrease consequences. [14] 2. Materials and Methods ...
... It is not true that after immersed cooling a subject is in a vasoplegic state. In fact the reduction in large cold-induced arterial and venous vasoconstrictive tone occurs over several hours (Robinet et al., 2006;Boussuges et al., 2009;Florian et al., 2013;Riera et al., 2014). Yes removing the squeezing effect of hydrostatic pressure precipitate rescue collapse (Lloyd, 1992). ...
... Nonetheless, the interindividual variations observed are not unique to these participants. Previous EMG studies have found large interindividual variations in the muscles activated within both groups of recreational cyclists (Jammes et al. 2001) and trained cyclists (Hug et al. 2008). Additionally, a recent study has shown that individuals can accurately be identified using a machine learning algorithm based on sEMG recordings of their lower limb muscles during pedalling (Hug et al. 2019). ...
... Studies involving objective conditions with no full text available and those with non-English literature and abstracts were excluded. Studies involving outcome measures for the nervous system were also excluded (Jammes et al., 2003). The primary outcome was between-group differences in the HBO 2 and NN groups or changes from baseline. ...
... Hyperoxic exposure has a major impact on cardiovascular function in healthy subjects. Numerous studies have shown that cardiovascular responses to acute hyperoxia include a decrease in cardiac output related to the simultaneous decreases in heart rate and stroke volume [41][42][43]. Increases in mean blood pressure and systemic vascular resistance, and a decrease in arterial compliance, have been documented in resting healthy volunteers breathing pure oxygen [41,44,45]. Such an effect of oxygen appears to be related to its vasoconstrictive action on the peripheral vascular system. ...
... However, depending on when venous blood samples are taken in relation to the WI, diver aldosterone levels may not change before and after single and consecutive dives, although increases in central SNS activity were seen with the increased LF/HF ratio (85,87,177). The changes in heart rate may affect regional and systematic blood flow. ...
... Likewise, several studies have demonstrated that physical activity or sauna exposure, some hours before the dive, could have a cardiovascular-mediated preventive effect on VGE formation [17][18][19][20]. An animal model with rats demonstrated that a single bout of exercise 20 h pre-dive reduces VGE post-dive and also DCS occurrence and related mortality [21]. ...
... O predomínio de estudos demonstrando a superioridade da CI em relação a outros métodos na recuperação muscular se deve a sua atuação de modo sistêmico com seus efeitos positivos se diferenciando conforme o órgão ou sistema sobre o qual atua e aspectos considerado, conforme descrito a seguir: 1) metabolismo tecidual: redução da demanda de energia por meio da redução estresse metabólico da fibra muscular (Hom et al., 2004;White e Wells, 2013); 2) fluxo sanguíneo: vasoconstrição reflexa (Peiffer et al., 2009) responsável pela redução da influência de componentes inflamatórios responsáveis por dano à fibra muscular e edema (Pournot et al., 2011); 3) desvio de fluxo sanguíneo e edema: em associação com o efeito descrito anteriormente, a CI demonstrou em vários estudos reduzir o fluxo sanguíneo para fibras musculares sob condição de estresse induzido pelo exercício, reduzindo o potencial existente para instalação de edema nas mesmas, esse aspecto é ainda reforçado pela pressão hidrostática exercida pela água na qual o segmento encontra-se imerso (Peiffer et al., 2009;White e Wells, 2013); 4) efeitos neuromusculares: a redução da temperatura do segmento em imersão atua também sobre o sistema nervoso, reduzindo a velocidade de condução neural (Coulange et al., 2006) e consequentemente o espasmo muscular e dor muscular tardia em resposta ao exercício (Goodall e Howatson, 2008); 5) efeitos cardiovasculares: a imersão em água gelada tanto parcial (membros inferiores) quanto total (até o pescoço) têm demonstrado alterar a atividade cardíaca, restaurar o volume sanguíneo em vasos centrais antes desviado para os segmentos sob estresse induzido pelo exercício e aumentar a pré-carga cardíaca (Peiffer et al., 2009;Herrera et al., 2010); 6) efeitos endócrinos: o exercício e o resfriamento são considerados agentes estressores para o corpo, os efeitos do repouso e da CI sobre a alteração dos hormônios circulantes e a recuperação muscular ainda são pouco estudados e seus efeitos sobre o desempenho ainda precisam ser conhecidos. Esses hormônios modulam, por exemplo, o fluxo sanguíneo, a frequência cardíaca e respiratória, podendo deste modo serem relevantes durante a recuperação pós-exercício (White e Wells, 2013). ...