126 research outputs found

    Variability in energy cost of running at the end of a triathlon and a marathon

    Get PDF
    International audienceThe aim of this study was to investigate the increase in energy cost of running occurring at the end of a triathlon and a marathon event and to link them to the metabolic and hormonal changes, as well as to variations in stride length. Seven subjects took part in 3 experimental situations: a 2 h 15 min triathlon (30 min swimming, 60 min cycling and 45 min running), a 2 h 15 min marathon (MR) were the fast 45 min were run at the same speed as the triathlon run (TR), and a 45 min isolated run (IR) done at triathlon speed. The results show that energy cost during MR was higher than during TR (p < 0.01) (+ 8.9 %). Similar observations were made for pulmonary ventilation (+ 7.9 %) and heart rate (+ 6.3 %). Moreover, the values were significantly greater than the values obtained during the IR. TR and MR lead to greater weight loss (p < 0.01) (2.4±0.3 kg) than IR (1 ± 0.2 kg). The triathlon and the marathon produced a large decrease in plasma volume (respectively 19.6 ± 1.4 % and 12.9 ± 1.1 %) compared to IR (2 ± 0.4 %). Plasma renin activity was higher for the triathlon and the marathon than for the IR (p < 0.01). MR produces a significantly greater increase in plasma free fatty acids (F.F.A.) than TR (p < 0.05) and IR (p < 0.01). In addition, the F.F.A. at the end of TR were significantly higher than IR (p < 0.05). At the end of the trial the mean stride lengths for TR and IR were greater (+ 15 %) (p <0.01) than for MR. This study, carried out with subjects running overground, confirms the decrease in running efficiency previously shown at the end of a laboratory triathlon, and demonstrates that this decrease is lower than that occurring during a marathon

    The Cosmed K4 telemetry system as an accurate device for oxygen uptake measurements during exercise

    Get PDF
    International audienceThe purpose of this study was to test the accuracy of oxygen uptake (VO2) measurements using the Cosmed K4 portable telemetry system. This system of higher technology than the original Cosmed K2 device, contains a CO2 electrode allowing measurements alternatively by either the Cosmed K4 system (K4) or the CPX Medical Graphics (CPX) during a maximum oxygen uptake (VO 2 max) ergocycle test, at rest and during several submaximal exercices (25, 50 and 75% of maximal work rate) in seven subjects. Heart rate values were comparable for exercise at the same work stage during gas collection using the two systems, indicating that the physiological stresses were similar. The VO 2 values did not significantly differ at rest (4.40 ± 0.83 vs 4.16 ± 0.58 ml • min-1 kg-1), at 25% Wmax (20.97 ± 1.31 vs 21.32 ± 2.54 ml • min-1 • kg-1), at 50% Wmax (33.32 ± 3.92 vs 33.50 ± 3.51 ml • min-1. kg-1), at 75% Wmax (47.01 ± 7.51 vs 47.49 ± 7.11 ml • min-1. kg-') and at maximal intensities (62.07 ± 8.48 vs 62.84 ± 11.31 ml • min-1. kg-1) using K4 and CPX devices, respectively. The results of this study indicated that the K4 system was accurate for all oxygen uptake measurements from rest to maximum exercise levels

    Preparticipation medical evaluation for elite athletes : EFSMA recommendations on standardised preparticipation evaluation form in European countries

    Get PDF
    Publisher Copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Sports medicine is a medical specialty that supports the performance of professional and amateur athletes while maintaining their health. Sports medicine professionals need to ensure the safe participation of athletes in sports activities achieved through a periodical preparticipation evaluation (PPE) and a regular medical monitoring of the athletes' health in accordance with the latest recommendations regarding health condition and medical history, physical working capacity, training period and programme, recovery, nutrition, use of supplements, injuries prevention and safe return to play. In order to harmonise these national variations in the content and application of the PPE, the EFSMA Scientific and Educational Commission proposes a € gold standard' for elite athletes across Europe. Important objectives of PPE are early detection and prevention of severe complications during sports activities both in leisure time and competitive sports. The PPE should entail the following diagnostic components: health status, anthropometry, functional and exercise capacity. It is of utmost importance to develop and implement preventive strategies such as the PPE. Besides monitoring the health status of athletes, the PPE plays an important role in the selection process, bringing valuable information for coaches and supporting a personalised treatment approach. Screening of athletes through a standardised digital PPE could be beneficial for a better understanding of the impact of long-term physical activity. Furthermore, PPE leads the scientific community to a way of working closer together in the interest of the athletes.Peer reviewe

    Methods for epidemiological studies in competitive cycling:an extension of the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sport 2020

    Get PDF
    In 2020, the IOC released a consensus statement that provides overall guidelines for the recording and reporting of epidemiological data on injury and illness in sport. Some aspects of this statement need to be further specified on a sport-by-sport basis. To extend the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sports and to meet the sport-specific requirements of all cycling disciplines regulated by the Union Cycliste Internationale (UCI). A panel of 20 experts, all with experience in cycling or cycling medicine, participated in the drafting of this cycling-specific extension of the IOC consensus statement. In preparation, panel members were sent the IOC consensus statement, the first draft of this manuscript and a list of topics to be discussed. The expert panel met in July 2020 for a 1-day video conference to discuss the manuscript and specific topics. The final manuscript was developed in an iterative process involving all panel members. This paper extends the IOC consensus statement to provide cycling-specific recommendations on health problem definitions, mode of onset, injury mechanisms and circumstances, diagnosis classifications, exposure, study population characteristics and data collection methods. Recommendations apply to all UCI cycling disciplines, for both able-bodied cyclists and para-cyclists. The recommendations presented in this consensus statement will improve the consistency and accuracy of future epidemiological studies of injury and illness in cycling

    Infographic. Clinical recommendations for return to play during the COVID-19 pandemic

    Get PDF
    COVID-19 AND RETURN TO PLAY The world of sport has recently returned to training and competition following suspension due to the COVID-19 pandemic. It is concerning that a number of athletes have tested positive for COVID-19 after returning to competition. 1 Numerous authors have attempted to address return to play given the importance and complexity of the issue, with notable attention on possible cardiac implications.2–6 SCOPE OF THE INFOGRAPHIC The specific recommendations shown in the present infographic (figure 1) have been generated by a panel of international experts and represent a compilation of the numerous approaches used to inform resumption of regular sports during the COVID-19 pandemic. Despite the different regulations around the world and the particular characteristics of each sport, it is essential to provide informative, consistent and specific guidance for safe return to training and competition at this most difficult time. ..

    Muscle inactivation of mTOR causes metabolic and dystrophin defects leading to severe myopathy

    Full text link
    Mammalian target of rapamycin (mTOR) is a key regulator of cell growth that associates with raptor and rictor to form the mTOR complex 1 (mTORC1) and mTORC2, respectively. Raptor is required for oxidative muscle integrity, whereas rictor is dispensable. In this study, we show that muscle-specific inactivation of mTOR leads to severe myopathy, resulting in premature death. mTOR-deficient muscles display metabolic changes similar to those observed in muscles lacking raptor, including impaired oxidative metabolism, altered mitochondrial regulation, and glycogen accumulation associated with protein kinase B/Akt hyperactivation. In addition, mTOR-deficient muscles exhibit increased basal glucose uptake, whereas whole body glucose homeostasis is essentially maintained. Importantly, loss of mTOR exacerbates the myopathic features in both slow oxidative and fast glycolytic muscles. Moreover, mTOR but not raptor and rictor deficiency leads to reduced muscle dystrophin content. We provide evidence that mTOR controls dystrophin transcription in a cell-autonomous, rapamycin-resistant, and kinase-independent manner. Collectively, our results demonstrate that mTOR acts mainly via mTORC1, whereas regulation of dystrophin is raptor and rictor independent

    Recommendations for return to sport during the SARS-CoV-2 pandemic

    Get PDF
    In this viewpoint we make specific recommendations that can assist and make the return to sport/exercise as safe as possible for all those impacted - from the recreational athlete to the elite athlete. We acknowledge that there are varying rules and regulations around the world, not to mention the varying philosophies and numerous schools of thought as it relates to return to sport/exercise and we have been cognisant of this in our recommendations. Despite the varying rules and circumstances around the world, we believe it is essential to provide some helpful and consistent guidance for return to training and sport for sport and exercise physicians around the world at this most difficult time. The present viewpoint provides practical and medical recommendations on the resumption to sport process.</p

    Recommendations for return to sport during the SARS-CoV-2 pandemic

    Get PDF
    In this viewpoint we make specific recommendations that can assist and make the return to sport/exercise as safe as possible for all those impacted - from the recreational athlete to the elite athlete. We acknowledge that there are varying rules and regulations around the world, not to mention the varying philosophies and numerous schools of thought as it relates to return to sport/exercise and we have been cognisant of this in our recommendations. Despite the varying rules and circumstances around the world, we believe it is essential to provide some helpful and consistent guidance for return to training and sport for sport and exercise physicians around the world at this most difficult time. The present viewpoint provides practical and medical recommendations on the resumption to sport process

    Recommendations for Face Coverings While Exercising During the COVID-19 Pandemic

    Get PDF
    In an effort to reduce transmission and number of infections of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or COVID-19) virus, governments and official bodies around the world have produced guidelines on the use of face masks and face coverings. While there is a growing body of recommendations for healthcare professionals and the wider population to use facial protection in “enclosed spaces” where minimal distancing from other individuals is not possible, there is a dearth of clear guidelines for individuals undertaking exercise and sporting activity. The present viewpoint aims to propose recommendations for face coverings while exercising during the COVID-19 pandemic that consider physical distancing, the environment, the density of active cases associated with the specific sports activity, and the practical use of face coverings in order to reduce potential viral transmission. Recommendations are provided on the basis of very limited available evidence in conjunction with the extensive collective clinical experience of the authors and acknowledging the need to consider the likelihood of the presence of the SARS-CoV-2 in the general population. We recommend that face coverings should be used in any environment considered to be of a high or moderate transmission risk, where tolerated and after individual risk assessment. In addition, as national caseloads fluctuate, individual sporting bodies should consider up to date guidance on the use of face coverings during sport and exercise, alongside other preventative measures

    Methods for epidemiological studies in competitive cycling: an extension of the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sport 2020

    Get PDF
    In 2020, the IOC released a consensus statement that provides overall guidelines for the recording and reporting of epidemiological data on injury and illness in sport. Some aspects of this statement need to be further specified on a sport-by-sport basis. To extend the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sports and to meet the sport-specific requirements of all cycling disciplines regulated by the Union Cycliste Internationale (UCI). A panel of 20 experts, all with experience in cycling or cycling medicine, participated in the drafting of this cycling-specific extension of the IOC consensus statement. In preparation, panel members were sent the IOC consensus statement, the first draft of this manuscript and a list of topics to be discussed. The expert panel met in July 2020 for a 1-day video conference to discuss the manuscript and specific topics. The final manuscript was developed in an iterative process involving all panel members. This paper extends the IOC consensus statement to provide cycling-specific recommendations on health problem definitions, mode of onset, injury mechanisms and circumstances, diagnosis classifications, exposure, study population characteristics and data collection methods. Recommendations apply to all UCI cycling disciplines, for both able-bodied cyclists and para-cyclists. The recommendations presented in this consensus statement will improve the consistency and accuracy of future epidemiological studies of injury and illness in cycling.http://bjsm.bmj.comhj2021Sports Medicin
    corecore