Is the Most Commonly Used Strategy for the First 1,500 m of a 2,000 m Rowing Ergometer Race the Most Appropriate?

International audienceThis study investigated time-courses of physiological and psychological parameters of rowers during the first 1,500 m of a simulated race on a rowing ergometer using different pacing strategies. This provided a picture of the physiological and psychological state of the rowers at the start of the last 500 m of their race. Investigated strategies corresponded either to a degressive ( degr ), a progressive ( prog ), or a stable ( stab ) power output over the traveled distance. Thirteen French rowers (4 oarswomen and 9 oarsmen) of national and ex-international levels volunteered to participate. Handle force and velocity, oxygen uptake, heart rate, blood lactate concentration, and peripheral oxygen saturation were measured during the trials. Power output, generated energy [by O 2 consumption ( E oxi ) and blood lactate accumulation ( E non − oxi )] and efficiency were computed. Rowers also rated their perceived exertion ( RPE ) and protocol preference. In the explored strategies, no significant differences were found for E oxi . Final blood lactate concentration ([ La ] blood ) and RPE were similar for all strategies. However, the increase in [ La ] blood and RPE occurred sooner for degr than for stab and prog . Therefore, the time spent at higher [ La ] blood and RPE was longer for degr than for stab and prog . According to the questionnaire, degr was the least preferred protocol. While during 2000 m races, the first 1500 m are usually and empirically often conducted in a degr way, the present results indicate that this strategy was the least preferred by the rowers and led to a higher time spent at high [ La ] blood and RPE

Activités physiques et maintien des fonctions cognitives

International audienceA l’heure où le vieillissement de la population devient une préoccupation grandissante, avec ses enjeux économiques, sociétaux, et de politique de santé, les recherches portant sur les possibles facteurs de protection tel que l’activité physique (AP) s’intensifient. Objectifs : La présente étude examine l’impact de la pratique d’une AP au cours de la vie sur les performances cognitives. Plus spécifiquement, il s’agit d’évaluer dans quelle mesure l’effet de l’AP régulière change selon l’âge au cours du vieillissement et diffère selon le type de fonction cognitive considérée. Méthodologie : Plus de 120 participants en bonne santé habituelle âgés de 18 à 82 ans ont participé à l’étude. Ils ont complétés des questionnaires sur leur pratique de l’AP et ont été catégorisés en sédentaires ou actifs selon leur niveau d’activité physique récente (6 derniers mois) et antérieure (tout au long de la vie). Ils ont réalisés diverses tâches cognitives notamment exécutives évaluant l’inhibition, la mise à jour et la flexibilité mentale. Résultats : Les résultats met en évidence un effet positif de l’AP récente sur la cognition. Cependant, cet effet n’est pas le même selon l’âge et le sexe des participants. Cet effet est spécifique au type de processus exécutif impliqué dans les tâches. Enfin, l’activité antérieure ne semble pas influencer les résultats. Conclusion : Cette étude révèle l’importante hétérogénéité qui semble apporter un éclairage nouveau quant à la réflexion sur le rôle d’une AP adaptée dans la prévention des troubles cognitifs

ILC Reference Design Report Volume 1 - Executive Summary

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization

ILC Reference Design Report Volume 4 - Detectors

This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics.This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics

ILC Reference Design Report Volume 3 - Accelerator

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC

International Linear Collider Reference Design Report Volume 2: PHYSICS AT THE ILC

This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described.This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described