cycling

骑自行车
  • 文章类型: Journal Article
    与根据血液乳酸浓度或气体交换数据的全身变化确定运动阈值相比,基于肌氧饱和度确定断点提供了一种有效的替代方法,可以提供有关肌肉衍生阈值的具体信息.我们的研究探索了不同肌肉中第二肌肉氧合阈值(MOT2)的分布和时间。26名自行车运动员和铁人三项运动员(15名男性:年龄=23±7岁,高度=178±5厘米,体重=70.2±5.3kg;11名女性:年龄=22±4岁,高度=164±4厘米,体重=58.3±8.1kg)进行了分级运动测试(GXT),在自行车测力计上。功率输出,血乳酸浓度,心率,感知努力的评级,在五块肌肉中记录了皮肤褶皱和肌肉氧饱和度(股外侧肌,股二头肌,中腓肠肌,胫骨前肌和肱三头肌)以及使用指数Dmax确定每条肌肉发生MOT2的百分比。统计参数图和方差分析的结果表明,尽管在GXT期间,肌肉氧合在每个肌肉中显示出不同的特征,MOT2发生在每个肌肉中GXT的相似百分比(77%股二头肌,75%的前胫骨,76%的腓肠肌内侧和72%的股外侧肌),与全身阈值(GXT的73%)相似。总之,这项研究显示了不同肌肉中不同的肌氧饱和度,但MOT2的时间和与全身阈值的一致性没有显着差异。最后,我们建议对整个信号进行分析,而不是将其简化为断点。
    Compared to the determination of exercise thresholds based on systemic changes in blood lactate concentrations or gas exchange data, the determination of breakpoints based on muscle oxygen saturation offers a valid alternative to provide specific information on muscle-derived thresholds. Our study explored the profiles and timing of the second muscle oxygenation threshold (MOT2) in different muscles. Twenty-six cyclists and triathletes (15 male: age = 23 ± 7 years, height = 178 ± 5 cm, body mass = 70.2 ± 5.3 kg; 11 female: age = 22 ± 4 years, height = 164 ± 4 cm, body mass = 58.3 ± 8.1 kg) performed a graded exercise test (GXT), on a cycle ergometer. Power output, blood lactate concentration, heart rate, rating of perceived exertion, skinfolds and muscle oxygen saturation were registered in five muscles (vastus lateralis, biceps femoris, gastrocnemius medialis, tibialis anterior and triceps brachii) and percentage at which MOT2 occurred for each muscle was determinated using the Exponential Dmax. The results of Statistical Parametric Mapping and ANOVA showed that, although muscle oxygenation displayed different profiles in each muscle during a GXT, MOT2 occurred at a similar percentage of the GXT in each muscle (77% biceps femoris, 75% tibalis anterior, 76% gastrocnemius medialis and 72% vastus lateralis) and it was similar that systemic threshold (73% of the GXT). In conclusion, this study showed different profiles of muscle oxygen saturation in different muscles, but without notable differences in the timing for MOT2 and concordance with systemic threshold. Finally, we suggest the analysis of the whole signal and not to simplify it to a breakpoint.
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  • 文章类型: Journal Article
    雷恩,法国的一个中型城市,具有许多积极旅行的机会。市政官员寻求到2030年增加步行和骑自行车,以改善公共卫生。身体不活动,全球过早死亡的主要风险因素,已被证明与许多慢性疾病相关,包括心脏病,2型糖尿病,和癌症。
    使用2018年对雷恩居民的家庭旅行调查,我们应用以健康为导向的交通统计模型来评估与人口水平的步行和骑自行车率相关的健康影响。我们考虑了两个拟议的交通和气候目标,这些目标概述了到2030年的可持续交通目标。其中包括交通方式份额的转变,以增加步行和骑自行车的旅行,以及在大都市地区行驶的车辆里程(VMT)大幅减少。
    我们的回归分析表明,家用汽车和内城居住权的因素是患病率的预测因素(观察到从事步行或骑自行车的一天比例),参与(每周比例),和活动旅行的强度(通过步行/骑自行车实现的平均个人体力活动)。年龄和教育程度也与患病率相关。2030年移动性目标(模式份额:9%周期,35%步行)与1,051个DALYs(残疾调整寿命年)减少相关,换算为7300万美元(23-177美元)的避免费用。气候目标(VMT减少10%)与完全由步行代替的369DALYs和714DALYs循环的减少有关。相当于节省了2600万美元(8-62美元)和5000万美元(15-121美元),分别。
    雷恩居民在积极旅行中的参与度很高,特别是那些在市中心的人。如果居民实现2030年城市的积极出行目标,就有可能大幅减少健康负担和后续费用。实现这些目标可能需要在交通规划和基础设施方面进行大量投资,以改善主动旅行机会。
    UNASSIGNED: Rennes, a midsize city in France, features many opportunities for active travel. City officials seek to increase walking and cycling by 2030 to improve public health. Physical inactivity, a leading risk factor for premature mortality around the globe, has been shown to be associated with many chronic diseases including heart disease, type 2 diabetes, and cancer.
    UNASSIGNED: Using the 2018 household travel survey of Rennes residents, we apply the Health-Oriented Transportation statistical model to assess health impacts associated with population-level rates of walking and cycling. We consider two proposed mobility and climate objectives which outline sustainable transportation goals by 2030. These include a shift in transportation mode share to increase walking and cycling trips, as well as a broad reduction in vehicle miles traveled (VMT) across the metropolitan area.
    UNASSIGNED: Our regression analysis demonstrated that factors of household car access and inner-city residency were predictors of prevalence (observed one-day proportion engaging in walking or cycling), participation (weekly proportion), and intensity (mean individual physical activity achieved through walking/cycling) of active travel. Age and education were additionally associated with prevalence. The 2030 mobility objective (mode share: 9% cycle, 35% walk) was associated with a reduction of 1,051 DALYs (disability-adjusted life-years), translating to $73 million USD ($23-$177) in averted costs. The climate objective (10% reduction in VMT) was associated with a reduction of 369 DALYs when replaced entirely by walking and 714 DALYs with cycling, translating to $26 million ($8-$62) and $50 million ($15-$121) saved, respectively.
    UNASSIGNED: Rennes residents experience high participation in active travel, particularly those in the inner city. If residents achieve the city\'s active travel goals for 2030, there is potential for a large reduction in health burden and subsequent costs. Reaching these goals may require significant investment in transportation programming and infrastructure to improve active travel opportunities.
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  • 文章类型: Journal Article
    铁人三项比赛的大多数参与者都是年龄组运动员。我们对休闲运动员的训练和比赛参与有广泛的了解。尽管如此,铁人年龄组铁人三项运动员必须达到快速的比赛时间才能获得在夏威夷举行的铁人世界锦标赛的资格。他们可以,因此,受益于知道世界上最快的铁人赛马场在哪里。本研究的目的是调查世界上年龄组铁人三项运动员最快的铁人三项赛马场。分析了来自228个国家的677,702个Ironman年龄组完成者的数据(男性544963个,女性132739个),并在2002年至2022年期间参加了66个不同Ironman比赛地点的444项赛事。通过传统的描述性统计和机器学习回归模型对数据进行分析。测试了四种算法(随机森林回归,XGBoostRegressor,CatBootRegressor,和决策树回归器)。模型使用性别,年龄组,原产国,环境因素(平均空气和水温),和事件位置作为独立变量来预测最终的整体比赛时间。尽管大多数成功的铁人三项运动员来自美国(274,553),其次是来自英国(55,410)和加拿大(38,264)的运动员,与速度最快的国家相比,这些国家的平均比赛时间要慢得多。大多数铁人三项运动员都在威斯康星州的铁人比赛(38,545),其次是佛罗里达铁人(38,157)和普莱西德湖铁人(34,341)。在Ironman哥本哈根实现了最快的整体比赛时间(11.68±1.38h),其次是夏威夷铁人(11.72±1.86小时),巴塞罗那铁人(11.78±1.43h),IronmanFlorianópolis(11.80±1.52小时),法兰克福铁人(12.03±1.38小时)和卡尔马铁人(12.08±1.47小时)。最快的运动员来自比利时(11.48±1.47h),其次是来自丹麦的运动员(11.59±1.40h),瑞士(11.62±1.49小时),奥地利(11.68±1.50),芬兰(11.68±1.40h)和德国(11.74±15.1h)。平坦的跑步和自行车路线与更快的整体比赛时间相关。其中三个预测模型将“国家/地区”和“年龄组”变量确定为最重要的预测因子。环境特征对其他变量的影响最小。运动员的起源是最具预测性的变量,而环境特征的影响最小。平坦的自行车和平坦的跑步路线与更快的整体比赛时间相关。最快的整体比赛时间主要在欧洲比赛中实现,例如Ironman哥本哈根,Ironman夏威夷,铁人巴塞罗那,IronmanFlorianópolis,铁人法兰克福和铁人卡尔马。最快的铁人三项运动员来自比利时等欧洲国家,丹麦,瑞士,奥地利,芬兰,和德国。
    The majority of participants in Ironman triathlon races are age group athletes. We have extensive knowledge about recreational athletes\' training and competition participation. Nonetheless, Ironman age group triathletes must achieve fast race times to qualify for the Ironman World Championship in Hawaii. They can, therefore, benefit from knowing where the fastest Ironman racecourses in the world are. The aim of the present study was to investigate where the fastest Ironman racecourses for age group triathletes are located in the world. Data from 677,702 Ironman age group finishers\' records (544,963 from men and 132,739 from women) originating from 228 countries and participating in 444 events across 66 different Ironman race locations between 2002 and 2022 were analyzed. Data was analyzed through traditional descriptive statistics and with machine learning regression models. Four algorithms were tested (Random Forest Regressor, XG Boost Regressor, Cat Boot Regressor, and Decision Tree Regressor). The models used gender, age group, country of origin, environmental factors (average air and water temperatures), and the event location as independent variables to predict the final overall race time. Despite the majority of successful Ironman age group triathletes originating from the USA (274,553), followed by athletes from the United Kingdom (55,410) and Canada (38,264), these countries exhibited average overall race times that were significantly slower compared to the fastest countries. Most of the triathletes competed in Ironman Wisconsin (38,545), followed by Ironman Florida (38,157) and Ironman Lake Placid (34,341). The fastest overall race times were achieved in Ironman Copenhagen (11.68 ± 1.38 h), followed by Ironman Hawaii (11.72 ± 1.86 h), Ironman Barcelona (11.78 ± 1.43 h), Ironman Florianópolis (11.80 ± 1.52 h), Ironman Frankfurt (12.03 ± 1.38 h) and Ironman Kalmar (12.08 ± 1.47 h). The fastest athletes originated from Belgium (11.48 ± 1.47 h), followed by athletes from Denmark (11.59 ± 1.40 h), Switzerland (11.62 ± 1.49 h), Austria (11.68 ± 1.50), Finland (11.68 ± 1.40 h) and Germany (11.74 ± 15.1 h). Flat running and cycling courses were associated with faster overall race times. Three of the predictive models identified the \'country\' and \'age group\' variables as the most important predictors. Environmental characteristics showed the lowest influence regarding the other variables. The origin of the athlete was the most predictive variable whereas environmental characteristics showed the lowest influence. Flat cycling and flat running courses were associated with faster overall race times. The fastest overall race times were achieved mainly in European races such as Ironman Copenhagen, Ironman Hawaii, Ironman Barcelona, Ironman Florianópolis, Ironman Frankfurt and Ironman Kalmar. The fastest triathletes originated from European countries such as Belgium, Denmark, Switzerland, Austria, Finland, and Germany.
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  • 文章类型: Journal Article
    运动员的姿势对气动阻力有显著影响。尽管对不同运动中的气动阻力进行了广泛的研究,大多数研究只分析了有限数量的职位,并且没有通用的优化方法。在这项工作中,我们提出了一种方法来执行运动员姿势优化相对于气动阻力减少。该方法结合虚拟骨架方法来调整运动员的姿势,CFD模拟以评估给定姿势的阻力,和有效的全局优化,以找到最佳位置。我们通过优化自行车手的计时赛位置来演示该方法。骑车人位置用6个设计参数进行参数化,优化需要41个CFD模拟才能收敛。与初始姿势相比,最佳姿势的阻力减少了17%(不考虑自行车阻力)。该方法有可能使姿势优化更容易在广泛的运动,并导致深入了解一般姿势的空气动力学影响。
    An athlete\'s posture has a significant impact on aerodynamic drag. Although aerodynamic drag in different sports has been studied extensively, most studies have analysed only a limited number of positions, and no generalized methods for optimization are available. In this work, we present a methodology to perform athlete posture optimization with respect to aerodynamic drag reduction. The method combines the virtual skeleton methodology to adjust the athlete\'s posture, CFD simulations to evaluate the drag for a given posture, and efficient global optimization to find the optimum position. We demonstrate the method by optimizing the time trial position for a cyclist. The cyclist position was parameterized with 6 design parameters, and the optimization required 41 CFD simulations to converge. The optimal posture yielded a reduction in drag of 17 % compared to the initial posture (disregarding bicycle drag). The method has potential to make posture optimization more accessible across a wide range of sports, and lead to insight into the aerodynamic influence of posture in general.
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  • 文章类型: Journal Article
    运动员的营养需求将受到多种因素的影响,因此,对运动员的建议不能直接从健全者的建议中得出。缺乏有关准运动员饮食摄入量的信息,因此需要进行检查。这项研究通过食物频率问卷评估了31名副嗜好者的营养摄入量和饮食质量。根据饮食参考摄入量,大多数副氏症患者摄入的摄入量超过推荐的膳食摄入量(RDA)或足够的摄入量(AI).碘(男性=87%RDA;女性=62%RDA)或男性纤维(84%AI)未达到建议。女性维生素D和E不足的风险为26%。共有42%的女性和75%的男性不符合纤维建议(14克/1000千卡),只有三名运动员(所有女性)以推荐的omega-6与omega-3的比例4:1或更少消耗脂肪酸。运动员消耗谷物,水果,经常吃蔬菜,虽然全谷物,脉冲,油性鱼通常不太经常食用。Paracyclists似乎正在摄入或超过大多数营养素的建议,尽管几种营养素的摄入量低于推荐量;因此,建议增加食用的食物种类。
    Nutrient requirements for para-athletes will be influenced by a variety of factors secondary to their impairment and, therefore, recommendations for para-athletes cannot be drawn directly from that of able-bodied athletes. Information on the dietary intakes of para-athletes is lacking and therefore needs to be examined. This study assessed the nutrient intakes and diet quality of 31 paracyclists via food frequency questionnaires. Based on the dietary reference intakes, most paracyclists consumed intakes above the recommended dietary allowance (RDA) or adequate intake (AI). Recommendations were not met for iodine (males = 87% RDA; females = 62% RDA) or fibre in males (84% AI). A 26% risk of inadequacy was noted for vitamins D and E in females. A total of 42% of females and 75% of males did not meet fibre recommendations (14 g/1000 kcal), and only three athletes (all females) consumed fatty acids in the recommended omega-6 to omega-3 ratio of 4:1 or less. Athletes consumed grains, fruits, and vegetables frequently, though whole grains, pulses, and oily fish were generally consumed less often. Paracyclists appear to be consuming intakes at or above recommendations for most nutrients, though several nutrients were consumed below the recommended amounts; therefore, increasing the variety of foods consumed is suggested.
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  • 文章类型: Journal Article
    推进力是决定短跑自行车性能的因素之一。踩踏率与功率输出有关,和刚度与提高运动任务的表现有关。
    目的:探讨肌关节僵硬度与踩踏率的关系。
    方法:22健康,未经训练的男性志愿者(19±2岁,175±6cm,74±16kg)在测试其肌肉关节(MA)刚度后分为两组,这些组是僵硬组(SG)和顺应性组(CG)。在四种循环模式下进行了6秒最大循环测试,是5级和10级空气阻力,3级和7级磁阻。峰值和平均节奏,峰值功率输出(POpeak),曲柄力(CFpeak),曲柄力发展的峰值速率(RCFD),并收集曲柄力峰值的角度。使用独立样本t检验评估两组之间对于这些变量的差异的显著性。计算了皮尔逊积矩相关性,以分析MA刚度与每个性能变量之间的关系。
    结果:SG在3级磁阻时具有明显更高的峰值节奏和平均节奏,峰值曲柄力,和峰值功率输出在10级空气阻力,在5级空气阻力时曲柄力发展的峰值速率,10空气阻力,和3磁阻(p<0.05)。MA刚度与5级和10级空气阻力的平均节奏显着相关,所有4种模式下的峰值曲柄力,和RCFD和峰值功率输出在10级空气阻力。在每种循环模式下,MA刚度与曲柄力峰值角之间没有显着关系。
    结论:结果表明,在这些条件下,具有相对较高MA硬度的参与者在6秒冲刺循环中似乎具有较高的踩踏率。他们还表现出优异的曲柄力和曲柄力发展速度,在冲刺循环时产生更大的功率输出。优化循环阻力或齿轮比以增强RCFD和肌肉肌腱刚度对于改善短跑循环性能至关重要。
    Propulsive power is one of the factors that determine the performance of sprint cycling. Pedaling rate is related to power output, and stiffness is associated with improving performance in athletic tasks.
    OBJECTIVE: to investigate the relationship between musculoarticular stiffness and pedaling rate.
    METHODS: twenty-two healthy, untrained male volunteers (19 ± 2 years, 175 ± 6 cm, 74 ± 16 kg) were divided into two groups after their musculoarticular (MA) stiffness was tested, and these groups were the stiffness group (SG) and compliant group (CG). A 6-s maximal cycling test was conducted in four cycling modes, which were levels 5 and 10 air-resistance, and levels 3 and 7 magnetic-resistance. Peak and average cadence, peak power output (POpeak), crank force (CFpeak), peak rate of crank force development (RCFD), and the angle of peak crank force were collected. The significance of differences between the two groups for these variables was assessed using an independent samples t-test. Pearson product-moment correlations were calculated to analyze the relationship between MA stiffness and each performance variable.
    RESULTS: the SG had significantly higher peak cadence and average cadence at level 3 magnetic-resistance, peak crank force, and peak power output at level 10 air-resistance, peak rate of crank force development at levels 5 air-resistance, 10 air-resistance, and 3 magnetic-resistance (p < 0.05). MA stiffness was significantly correlated with average cadence at levels 5 and 10 air-resistance, peak crank force in all 4 modes, and RCFD and peak power output at level 10 air-resistance. There were no significant relationships between MA stiffness and the angle of peak crank force in each cycling mode.
    CONCLUSIONS: results indicate that participants with relatively higher MA stiffness seemed to have a higher pedaling rate during a 6-s sprint cycling in these conditions. They also performed a superior crank force and rate of crank force development, producing greater power output when sprint cycling. Optimizing cycling resistance or gear ratio to enhance both RCFD and musculotendinous stiffness may be crucial for improving sprint cycling performance.
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  • 文章类型: Journal Article
    引言本研究调查了2017年至2021年间自行车相关伤害率的变化。我们特别关注年龄人口统计学的变化,以及最常见的诊断和身体部位受伤。方法我们向国家电子伤害监测系统(NEISS)查询了2017年至2021年与自行车相关的伤害。卡方分析用于评估损伤与损伤的趋势。整个样本的时间,以五年为增量的年龄组,以及诊断和身体部位损伤类型的比例。结果2020年年伤害率最高(12800次),与COVID-19家庭安全秩序一致。儿科患者继续占受伤骑自行车者的大多数(48%的患者年龄在19岁以下),但他们的百分比正在下降(零到四年(-13%,p<0.005),五到九年(-17%,p<0.005),10-14年(-5%,p<0.005),20-24年(-16%,p<0.005),25-29年(-2%,p<0.005),50-54岁(-14%,p<0.005)),并反映在老年受伤自行车手比例的增加(40-44岁(+26%,p<0.005),60-64岁(+44%,p<0.005),65-69岁(+69%,p<0.005),和70+年(+57%,p<0.005))。在过去的五年中,与更高的冲击力以及更严重的发病率和死亡率有关的伤害有所增加,例如内脏器官损伤(+13%,p<0.01)。脑震荡的发生率,然而,没有明显变化。四肢是最常受伤的身体部位(上臂和下臂,弯头,手腕,手,手指,大腿和小腿,膝盖,脚踝,脚,和脚趾=47%),并继续增加频率(下臂(+2%,p<0.005),小腿(+3%,p<0.01),上臂(+18%,p<0.005),和手(+11%,p<0.05)),而面部损伤变得越来越不常见(-3%,p<0.05),头部损伤的发生率没有明显变化。结论尽管在COVID-19家庭安全订单期间,自行车相关伤害有所增加,此后,数字已恢复到COVID-19之前的水平。自行车伤害人口统计学和机制的其他变化,例如老年成年骑自行车者的增加和强力机制伤害,然而,呼吁重新评估预防和治疗的优先事项。
    Introduction This study investigates the changes in bicycle-related injury rates between 2017 and 2021. We focus specifically on changes in age demographics, and the most common diagnoses and body parts injured. Methods We queried the National Electronic Injury Surveillance System (NEISS) for injuries associated with bicycles from 2017 to 2021. Chi-square analysis was used to evaluate trends in injuries vs. time for the entire sample, age groups in five-year increments, and the proportion of injury types by diagnosis and body part. Results The highest annual injury rate (12,800 counts) occurred in 2020, coinciding with the COVID-19 safer-at-home order. Pediatric patients continue to make up the majority of injured cyclists (48% of patients are younger than 19 years), but their percentage is decreasing (zero to four years (-13%, p < 0.005), five to nine years (-17%, p < 0.005), 10-14 years (-5%, p < 0.005), 20-24 years (-16%, p < 0.005), 25-29 years (-2%, p < 0.005), and 50-54 years (-14%, p < 0.005)) and mirrored by an increase in the proportion of older injured cyclists (40-44 years (+26%, p < 0.005), 60-64 years (+44%, p < 0.005), 65-69 years (+69%, p < 0.005), and 70+ years (+57%, p < 0.005)). The past five years saw an increase in injuries associated with higher impact forces and the potential for more severe morbidity and mortality, such as internal organ injuries (+13%, p < 0.01). The incidence of concussions, however, has not changed significantly. The extremities are the most commonly injured body parts (upper and lower arm, elbow, wrist, hand, fingers, upper and lower leg, knee, ankle, foot, and toe = 47% total) and continue to increase in frequency (lower arm (+2%, p < 0.005), lower leg (+3%, p < 0.01), upper arm (+18%, p < 0.005), and hand (+11%, p < 0.05)), while facial injuries are becoming less common (-3%, p < 0.05), and head injuries have not experienced a significant change of incidence. Conclusion Although there was an increase in bicycle-related injuries during the COVID-19 safer-at-home order, numbers have since returned to pre-COVID-19 levels. Other changes in bicycle injury demographics and mechanisms, such as a rise in older adult cyclists and high-force mechanism injuries, however, call for a re-evaluation of preventive and treatment priorities.
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  • 文章类型: Journal Article
    这项研究旨在研究口香糖(GUMCAF)结合启动运动摄入咖啡因对循环过程中肺氧摄取(V*O2)和近红外光谱衍生的肌氧提取(HHbMb)动力学的影响在剧烈强度域中进行。15名受过训练的自行车手完成了四次访问:两次在安慰剂口香糖(GUMPLA)下进行,两次在GUMCAF摄入下进行。每次访问包括两个方波循环回合,强度为Δ70(第一通气阈值下的V•O2与V•O2max之间的差异的70%),每次持续时间为6分钟,两次回合之间的被动休息为5分钟。将GUMPLA或GUMCAF(400mg)咀嚼5分钟,在随机双盲程序中的第一次Δ70发作前12分钟。评估了HHbMb和V•O2动力学的基本相和慢成分。对于HHb+Mb动力学,不管摄入的口香糖,引发运动对时间常数的影响(GUMCAF16.0±4.0vs.13.9±2.9s;GUMPLA15.7±6.1vs.13.2±2.5s),振幅,慢速组件,时间延迟,和平均响应时间参数(p≤.032)。对于V•O2动力学,对振幅有很大的影响,慢速组件,终点V•O2和增益动力学参数(p<.017)。GUMCAF期间的基线V•O2高于GUMPLA(p=.020)。在V*O2或HHbMb动力学的任何参数下,口香糖与bout之间的相互作用均未发生显着影响。因此,与高强度运动中的启动运动不同,GUMCAF不是改善V*O2或HHbMb动力学加速的有效策略。
    This study aimed to investigate the effects of caffeine ingestion by chewing gum (GUMCAF) combined with priming exercise on pulmonary oxygen uptake (V˙O2) and near-infrared spectroscopy-derived muscle oxygen extraction (HHb + Mb) kinetics during cycling performed in a severe-intensity domain. Fifteen trained cyclists completed four visits: two under a placebo gum (GUMPLA) and two under GUMCAF ingestion. Each visit consisted of two square-wave cycling bouts at Δ70 intensity (70% of difference between the V˙O2 at first ventilatory threshold and V˙O2max) with duration of 6 min each and 5 min of passive rest between the bouts. The GUMPLA or GUMCAF (400 mg) was chewed for 5 min, 12 min before the first Δ70 bout in a randomized double-blind procedure. The fundamental phase and slow component of HHb + Mb and V˙O2 kinetics were evaluated. For HHb + Mb kinetics, regardless of ingested gum, priming exercise effects occurred on the time constant (GUMCAF 16.0 ± 4.0 vs. 13.9 ± 2.9 s; GUMPLA 15.7 ± 6.1 vs. 13.2 ± 2.5 s), amplitude, slow component, time delay, and mean response time parameters (p ≤ .032). For V˙O2 kinetics, there were significant effects of bouts on the amplitude, slow component, end V˙O2, and the gain kinetics parameters (p < .017). Baseline V˙O2 was higher during GUMCAF than GUMPLA (p = .020). No significant effects occurred for the interaction between gum and bout in any parameter of V˙O2 or HHb + Mb kinetics. Therefore, unlike the priming exercise in severe-intensity exercise, GUMCAF is not an effective strategy for improving V˙O2 or HHb + Mb kinetics acceleration.
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  • 文章类型: Journal Article
    在各种约束下获得运动能力是经过充分研究的;这里特别感兴趣的是有意识的处理和自我意识如何影响学习和表现。当前与这些变量相关的研究,例如,再投资,倾向于使用定量方法,因此忽略了潜在的丰富理解来源。因此,这项研究的目的是应用定性方法来探索参与非竞争性休闲活动的实践较少的成年人群体中的认知过程和自我意识。
    要做到这一点,对学习或重新学习骑自行车的成年女性进行了11次半结构化访谈。
    使用主题分析,两个不同的主题是显而易见的,并证实了在特定运动的再投资规模等规模中所说明的那些主题。这些主题包括有意识的处理,回顾经验和运动分析,除了运动风格,和自我意识。焦虑也成为学习新的复杂运动技能的附加和相关主题。
    调查结果表明,参与活动的女性在有意识地试图控制自己的动作的程度上调整了自己的动作,但关于自我意识改变的运动就不那么重要了。虽然需要进一步的研究,定性方法为探索参与学习的意识过程所涉及的认知过程提供了有希望的基础。
    UNASSIGNED: Attaining movement proficiency under various constraints is well-researched; of particular interest here is how conscious processing and self-consciousness influence learning and performance. Current research relevant to these variables e.g., reinvestment, tends to utilize quantitative methods and thus overlooks a potentially rich source of understanding. Therefore, the purpose of this study was to apply a qualitative approach to explore the cognitive processes and self-consciousness within a less practiced population of adults participating in a non-competitive leisure activity.
    UNASSIGNED: To achieve this, eleven semi-structured interviews were conducted with adult women learning or relearning to ride a bicycle.
    UNASSIGNED: Using thematic analysis, two distinct themes were evident and corroborated those illustrated in scales such as the movement-specific reinvestment scale. These themes included Conscious Processing, Recalling Experiences and Movement Analysis, in addition to Style of Movement, and Self-Consciousness. Anxiety also emerged as an additional and relevant theme to learning a new complex movement skill.
    UNASSIGNED: The findings indicated that participating women attuned to their movements to the extent that there was a conscious attempt to control their movements, but less so regarding movements being altered by self-awareness. Whilst further research is required, qualitative methods provide a promising basis for exploring the cognitive process involved with the conscious process involved in learning.
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  • 文章类型: Journal Article
    在哺乳动物和苍蝇中,昼夜节律大脑神经元协调生理振荡和行为,如唤醒和睡眠-这些神经元可以通过形态和基因表达模式细分。最近的单细胞测序研究确定了17个果蝇昼夜节律神经元群。其中之一仅包括两个外侧神经元(LN),以神经肽离子转运肽(ITP)的表达为标志。尽管这两个ITP+LN长期以来与其他五个昼夜节律活动细胞分组,单独抑制两个神经元会大大减少早晨的活动,表明他们也有突出的早晨功能。由于多巴胺信号促进果蝇的活动,就像哺乳动物一样,我们认为多巴胺可能会影响今天早上的活动功能。此外,ITP+LN表达的mRNA水平高于1型多巴胺受体Dop1R1的其他LN。与Dop1R1的重要性一致,在两个ITP+LN中,这种受体的细胞特异性CRISPR-Cas9诱变使果蝇在早晨的活动明显减弱,和离体活体成像显示了这两个神经元中Dop1R1依赖性环状AMP(cAMP)对多巴胺的反应。值得注意的是,早上反应更强烈,反映了两个神经元中更高的早晨Dop1R1mRNA水平。由于mRNA水平在持续黑暗中不会升高,这表明早晨Dop1R1转录水平的光依赖性上调。结合增强的早晨cAMP对多巴胺的反应,数据表明光和多巴胺如何促进苍蝇的早晨觉醒,模仿光线对人类早晨觉醒的重要影响。
    In both mammals and flies, circadian brain neurons orchestrate physiological oscillations and behaviors like wake and sleep-these neurons can be subdivided by morphology and by gene expression patterns. Recent single-cell sequencing studies identified 17 Drosophila circadian neuron groups. One of these includes only two lateral neurons (LNs), which are marked by the expression of the neuropeptide ion transport peptide (ITP). Although these two ITP+ LNs have long been grouped with five other circadian evening activity cells, inhibiting the two neurons alone strongly reduces morning activity, indicating that they also have a prominent morning function. As dopamine signaling promotes activity in Drosophila, like in mammals, we considered that dopamine might influence this morning activity function. Moreover, the ITP+ LNs express higher mRNA levels than other LNs of the type 1-like dopamine receptor Dop1R1. Consistent with the importance of Dop1R1, cell-specific CRISPR-Cas9 mutagenesis of this receptor in the two ITP+ LNs renders flies significantly less active in the morning, and ex vivo live imaging shows Dop1R1-dependent cyclic AMP (cAMP) responses to dopamine in these two neurons. Notably, the response is more robust in the morning, reflecting higher morning Dop1R1 mRNA levels in the two neurons. As mRNA levels are not elevated in constant darkness, this suggests light-dependent upregulation of morning Dop1R1 transcript levels. Taken together with the enhanced morning cAMP response to dopamine, the data indicate how light and dopamine promote morning wakefulness in flies, mimicking the important effect of light on morning wakefulness in humans.
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