Medicine and science in sports and exercise
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Med Sci Sports Exerc · Feb 2020
Physical Performance Measures Correlate with Head Impact Exposure in Youth Football.
Head impact exposure (HIE) (i.e., magnitude and frequency of impacts) can vary considerably among individuals within a single football team. To better understand individual-specific factors that may explain variation in head impact biomechanics, this study aimed to evaluate the relationship between physical performance measures and HIE metrics in youth football players. ⋯ Generally, higher vertical jump height and faster times in speed and agility drills were associated with higher HIE, especially in games. Physical performance explained less variation in HIE in practices, where drills and other factors, such as coaching style, may have a larger influence on HIE.
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Med Sci Sports Exerc · Aug 2019
Randomized Controlled TrialTestosterone and Resistance Training Improve Muscle Quality in Spinal Cord Injury.
Spinal cord injury (SCI) negatively impacts muscle quality and testosterone levels. Resistance training (RT) has been shown to increase muscle cross-sectional area (CSA) after SCI, whereas testosterone replacement therapy (TRT) has been shown to improve muscle quality in other populations. The purpose of this pilot study was to examine if the combined effects of these interventions, TRT + RT, may maximize the beneficial effects on muscle quality after SCI. ⋯ The addition of mechanical stress via RT to TRT maximizes improvements to muscle quality after complete SCI when compared with TRT administered alone. Our evidence shows that this intervention increases muscle size and strength while also improving muscle contractile properties.
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Med Sci Sports Exerc · Jun 2019
ReviewBenefits of Physical Activity during Pregnancy and Postpartum: An Umbrella Review.
This study aimed to summarize the evidence from the 2018 Physical Activity Guidelines Advisory Committee Scientific Report, including new evidence from an updated search of the effects of physical activity on maternal health during pregnancy and postpartum. ⋯ The gestational period is an opportunity to promote positive health behaviors that can have both short- and long-term benefits for the mother. Given the low prevalence of physical activity in young women in general, and the high prevalence of obesity and cardiometabolic diseases among the U.S. population, the public health importance of increasing physical activity in women of childbearing age before, during, and after pregnancy is substantial.
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Active youth are vulnerable to knee injury and subsequent osteoarthritis. Improved understanding of the association between health-related outcomes and history of joint injury could inform osteoarthritis prevention strategies. The purpose of this historical cohort study is to examine the association between youth sport-related knee injury and various clinical, physiological, behavioral, and functional health-related outcomes, 3-10 yr postinjury. ⋯ Youth that suffer a sport-related knee injury demonstrate on average more negative health-related outcomes consistent with future osteoarthritis compared with uninjured matched controls 3-10 yr after injury. These negative outcomes differ by sex and time since injury.
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Med Sci Sports Exerc · Jan 2019
O2 Pulse Patterns in Male Master Athletes with Normal and Abnormal Exercise Tests.
The clinical relevance of abnormal exercise testing (ET) results (at least 0.1 mV ST segment depression measured during exercise or recovery in three consecutive beats) in athletes without obstructive coronary artery disease (CAD) is not well understood. It is unknown whether this phenomenon reflects a physiological adaptation to sport or a truly ischemic response and a concomitant attenuated stroke volume (SV) response. The aim of this study was to investigate if athletes with abnormal ET results without obstructive CAD showed signs of an attenuated SV response using cardiopulmonary ET parameters. ⋯ Athletes with abnormal ET results without obstructive CAD showed an attenuated O2 pulse slope, decreased ΔV˙O2/ΔWR ratio, and increased ΔHR/ΔWR ratio beyond anaerobic threshold when compared with athletes with a normal ET result. These results support the hypothesis that at least a part of the athletes with an abnormal ET in absence of obstructive CAD have an attenuated SV response at high-intensity exercise.