986 resultados para Millet, Catherine


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Worldwide, about half the adult population is considered overweight as defined by a body mass index (BMI - calculated by body weight divided by height squared) ratio in excess of 25 kg.m-2. Of these individuals, half are clinically obese (with a BMI in excess of 30) and these numbers are still increasing, notably in developing countries such as those of the Middle East region. Obesity is a disorder characterised by increased mass of adipose tissue (excessive fat accumulation) that is the result of a systemic imbalance between food intake and energy expenditure. Although factors such as family history, sedentary lifestyle, urbanisation, income and family diet patterns determine obesity prevalence, the main underlying causes are poor knowledge about food choice and lack of physical activity3. Current obesity treatments include dietary restriction, pharmacological interventions and ultimately, bariatric surgery. The beneficial effects of physical activity on weight loss through increased energy expenditure and appetite modulation are also firmly established. Another viable option to induce a negative energy balance, is to incorporate hypoxia per se or combine it with exercise in an individual's daily schedule. This article will present recent evidence suggesting that combining hypoxic exposure and exercise training might provide a cost-effective strategy for reducing body weight and improving cardio-metabolic health in obese individuals. The efficacy of this approach is further reinforced by epidemiological studies using large-scale databases, which evidence a negative relationship between altitude of habitation and obesity. In the United States, for instance, obesity prevalence is inversely associated with altitude of residence and urbanisation, after adjusting for temperature, diet, physical activity, smoking and demographic factors.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: To assess the circadian variations in salivary immunoglobin A (sIgA) and alpha-amylase activity (sAA), biomarkers of mucosal immune function, together with mood during 2 weeks of repeated sprint training in hypoxia (RSH) and normoxia (RSN). METHODS: Over a 2-week period, 17 competitive cross-country skiers performed six training sessions, each consisting of four sets of five 10-s bouts of all-out double-poling under either normobaric hypoxia (FiO2: 13.8 %, 3000 m) or normoxia. The levels of sIgA and sAA activity and mood were determined five times during each of the first (T1) and sixth (T6) days of training, as well as during days preceding (baseline) and after the training intervention (follow-up). RESULTS: With RSH, sIgA was higher on T6 than T1 (P = 0.049), and sAA was increased on days T1, T6, and during the follow-up (P < 0.01). With RSN, sIgA remained unchanged and sAA was elevated on day T1 only (P = 0.04). Similarly, the RSH group demonstrated reduced mood on days T1, T6, and during the follow-up, while mood was lowered only on T1 with RSN (P < 0.01). CONCLUSIONS: The circadian variation of sIgA and sAA activity, biomarkers of mucosal immune function, as well as mood were similar on the first day of training when repeated double-poling sprints were performed with or without hypoxia. Only with RSH did the levels of sIgA and sAA activity rise with time, becoming maximal after six training sessions, when mood was still lowered. Therefore, six sessions of RSH reduced mood, but did not impair mucosal immune function.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Le but de cette étude est de mesurer ainsi que de qualifier l'impact de l'implication des proches aidants de patients hospitalisés dans des unités de soins psychiatriques aigus sur eux-mêmes. Le cadre conceptuel utilisé est celui du fardeau des familles de Schene (1990). Il différencie les parties objectives et subjectives du fardeau familial. La récolte de données a été réalisée à l'aide de l'Involvement Evaluation Questionnaire (IEQ). Les résultats de cette étude montrent que les proches aidants souffrent d'un niveau d'inquiétude élevé, 3.8 sur une échelle de Likert à 5 questions, ainsi que d'un niveau de tension à 2.44 sur une échelle de Likert à 5 questions. Des associations ont été trouvées. L'augmentation de la durée du trouble diminue l'inquiétude, avec une valeur ρ de 0.048. Le fait d'être habitué à la situation a également un impact en diminuant la tension, avec une valeur ρ de 0.002. Plus on est « habitué à la situation », avec une valeur ρ de -0.021, moins le proche est inquiet par rapport à la situation du patient. Ainsi que, plus le patient est jeune, plus le proche aidant ressent de tension, avec une valeur ρ de 0.008. Ces résultats, peu généralisables au vu du petit échantillon (n=24), pourraient toutefois impliquer une réflexion approfondie sur l'accueil, la place et le soutien des proches aidants de patients souffrants de troubles psychiatriques hospitalisés dans une unité de soins aigus de la part des infirmières.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Guex, KJ, Lugrin, V, Borloz, S, and Millet, GP. Influence on strength and flexibility of a swing phase-specific hamstring eccentric program in sprinters' general preparation. J Strength Cond Res 30(2): 525-532, 2016-Hamstring injuries are common in sprinters and mainly occur during the terminal swing phase. Eccentric training has been shown to reduce hamstring injury rate by improving several risk factors. The aim of this study was to test the hypothesis that an additional swing phase-specific hamstring eccentric training in well-trained sprinters performed at the commencement of the winter preparation is more efficient to improve strength, ratio, optimum angle, and flexibility than a similar program without hamstring eccentric exercises. Twenty sprinters were randomly allocated to an eccentric (n = 10) or a control group (n = 10). Both groups performed their usual track and field training throughout the study period. Sprinters in the eccentric group performed an additional 6-week hamstring eccentric program, which was specific to the swing phase of the running cycle (eccentric high-load open-chain kinetic movements covering the whole hamstring length-tension relationship preformed at slow to moderate velocity). Isokinetic and flexibility measurements were performed before and after the intervention. The eccentric group increased hamstring peak torques in concentric at 60 degrees .s by 16% (p < 0.001) and at 240 degrees .s by 10% (p < 0.01), in eccentric at 30 degrees .s by 20% (p < 0.001) and at 120 degrees .s by 22% (p < 0.001), conventional and functional ratios by 12% (p < 0.001), and flexibility by 4 degrees (p < 0.01), whereas the control group increased hamstring peak torques only in eccentric at 30 degrees .s by 6% (p </= 0.05) and at 120 degrees .s by 6% (p < 0.01). It was concluded that an additional swing phase-specific hamstring eccentric training in sprinters seems to be crucial to address different risk factors for hamstring strain injuries, such as eccentric and concentric strength, hamstring-to-quadriceps ratio ratio, and flexibility.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Long recognized as the standard general reference in the field, this completely revised edition of Grainger and Allison's Diagnostic Radiology provides all the information that a trainee needs to master to successfully take their professional certification examinations as well as providing the practicing radiologist with a refresher on topics that may have been forgotten. Organized along an organ and systems basis, this resource covers all diagnostic imaging modalities in an integrated, correlative fashion and focuses on those topics that really matter to a trainee radiologist in the initial years of training

Relevância:

10.00% 10.00%

Publicador:

Resumo:

De la sociologie de l'immigration vers les études transnationales? Les multiples approches de la sociologie des migrations en France.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Inferior vena cava anomalies are rare, occurring in up to 8.7% of the population, as left renal vein anomalies are considered. The inferior vena cava develops from the sixth to the eighth gestational weeks, originating from three paired embryonic veins, namely the subcardinal, supracardinal and postcardinal veins. This complex ontogenesis of the inferior vena cava, with multiple anastomoses between the pairs of embryonic veins, leads to a number of anatomic variations in the venous return from the abdomen and lower limbs. Some of such variations have significant clinical and surgical implications related to other cardiovascular anomalies and in some cases associated with venous thrombosis of lower limbs, particularly in young adults. The authors reviewed images of ten patients with inferior vena cava anomalies, three of them with deep venous thrombosis. The authors highlight the major findings of inferior vena cava anomalies at multidetector computed tomography and magnetic resonance imaging, correlating them the embryonic development and demonstrating the main alternative pathways for venous drainage. The knowledge on the inferior vena cava anomalies is critical in the assessment of abdominal images to avoid misdiagnosis and to indicate the possibility of associated anomalies, besides clinical and surgical implications.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s "all-out" sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; "fast" instruction) and maximal (~5 s; "hard" instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, -50, -100, and -200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (-8 ± 4% and 178 ± 11 m) but not in LA (-7 ± 3% and 181 ± 10 m) compared to NM (-5 ± 2% and 183 ± 9 m). Compared to NM (-9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (-14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (-6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (-8 ± 11%; P = 0.07) and RF (-14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0-100 (-8 ± 9%) and 0-200 ms (-10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values. Additionally, the EMG rise for VL muscle was similar (P > 0.05), whereas it increased (P < 0.05) for RF muscle during all epochs post-exercise, independently of the conditions. In summary, alteration in repeated-sprint ability and post-exercise MVC decrease were greater at high altitude than in normoxia or at low altitude. However, the post-exercise alterations in RTD were similar between normoxia and low-to-high hypoxia.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We determined if performance and mechanical running alterations during repeated treadmill sprinting differ between severely hot and hypoxic environments. Six male recreational sportsmen (team- and racket-sport background) performed five 5-s sprints with 25-s recovery on an instrumented treadmill, allowing the continuous (step-by-step) measurement of running kinetics/kinematics and spring-mass characteristics. These were randomly conducted in control (CON; 25°C/45% RH, inspired fraction of oxygen = 20.9%), hot (HOT; 38°C/21% RH, inspired fraction of oxygen = 20.9%; end-exercise core temperature: ~38.6°C) and normobaric hypoxic (HYP, 25°C/45% RH, inspired fraction of oxygen = 13.3%/simulated altitude of ~3600 m; end-exercise pulse oxygen saturation: ~84%) environments. Running distance was lower (P < 0.05) in HOT compared to CON and HYP for the first sprint but larger (P < 0.05) sprint decrement score occurred in HYP versus HOT and CON. Compared to CON, the cumulated distance covered over the five sprints was lower (P < 0.01) in HYP but not in HOT. Irrespective of the environmental condition, significant changes occurred from the first to the fifth sprint repetitions (all three conditions compounded) in selected running kinetics (mean horizontal forces, P < 0.01) or kinematics (contact and swing times, both P < 0.001; step frequency, P < 0.001) and spring-mass characteristics (vertical stiffness, P < 0.001; leg stiffness, P < 0.01). No significant interaction between sprint number and condition was found for any mechanical data. Preliminary evidence indicates that repeated-sprint ability is more impaired in hypoxia than in a hot environment, when compared to a control condition. However, as sprints are repeated, mechanical alterations appear not to be exacerbated in severe (heat, hypoxia) environmental conditions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: Slight physiological differences between acute exposure in normobaric hypoxia (NH) and hypobaric hypoxia (HH) have been reported. Taken together, these differences suggest different physiological responses to hypoxic exposure to a simulated altitude (NH) versus a terrestrial altitude (HH). For this purpose, in the present study, we aimed to directly compare the time-trial performance after acute hypoxia exposure (26 h, 3450 min) by the same subjects under three different conditions: NH, HH, and normobaric normoxia (NN). Based on all of the preceding studies examining the differences among these hypoxic conditions, we hypothesized greater performance impairment in HH than in NH. METHODS: The experimental design consisted of three sessions: NN (Sion: FiO2, 20.93), NH (Sion, hypoxic room: FiO2, 13.6%; barometric pressure, 716 mm Hg), and HH (Jungfraujoch: FiO2, 20.93; barometric pressure, 481 mm Hg). The performance was evaluated at the end of each session with a cycle time trial of 250 kJ. RESULTS: The mean time trial duration in NN was significantly shorter than under the two hypoxic conditions (P < 0.001). In addition, the mean duration in NH was significantly shorter than that in HH (P < 0.01). The mean pulse oxygen saturation during the time trial was significantly lower for HH than for NH (P < 0.05), and it was significantly higher in NN than for the two other sessions (P < 0.001). CONCLUSION: As previously suggested, HH seems to be a more stressful stimulus, and NH and HH should not be used interchangeability when endurance performance is the main objective. The principal factor in this performance difference between hypoxic conditions seemed to be the lower peripheral oxygen saturation in HH at rest, as well as during exercise.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: We aimed to a) introduce a new Test to Exhaustion Specific to Tennis (TEST) and compare performance (test duration) and physiological responses to those obtained during the 20-m multistage shuttle test (MSST), and b) determine to which extent those variables correlate with performance level (tennis competitive ranking) for both test procedures. METHODS: Twenty-seven junior players (8 males, 19 females) members of the national teams of the French Tennis Federation completed MSST and TEST, including elements of the game (ball hitting, intermittent activity, lateral displacement), in a randomized order. Cardiorespiratory responses were compared at submaximal (respiratory compensation point) and maximal loads between the two tests. RESULTS: At the respiratory compensation point oxygen uptake (50.1 +/- 4.7 vs. 47.5 +/- 4.3 mL.min-1.kg-1, p = 0.02), but not minute ventilation and heart rate, was higher for TEST compared to MSST. However, load increment and physiological responses at exhaustion did not differ between the two tests. Players' ranking correlated negatively with oxygen uptake measured at submaximal and maximal loads for both TEST (r = -0.41; p = 0.01 and -0.55; p = 0.004) and MSST (r = -0.38; P = 0.05 and -0.51; p = 0.1). CONCLUSION: Using TEST provides a tennis-specific assessment of aerobic fitness and may be used to prescribe aerobic exercise in a context more appropriate to the game than MSST. Results also indicate that VO2 values both at submaximal and maximal load reached during TEST and MSST are moderate predictors of players competitive ranking.