致亲爱的读者

亲爱的读者: 你们好! 进入惊蛰,春雷始鸣,万物生机盎然,正是春耕农忙时.新的开始,新的生长,天地之间澎湃着新的希望. 过去的一个月,全世界都在为冰雪健儿喝彩,为他们的每一次拼尽全力而热血沸腾.我们的官方微信公众号推出冬奥特辑,记录赛场上的精彩,铭记这一场盛会的荣光."美美与共"是各国人民的共同期望.然而在冬奥会进行之...     

心脏康复中运动终止原因的预测

目的:通过分析心肌梗塞后患者(PMI患者)运动中功能、生理、知觉和临床的反应,检测他们运动终止的主要原因(RET),目的在于确定RET是否可被预测得出;方法:112名男性近期PMI患者在活动跑台上进行递增负荷运动实验,运动终止依美国运动医学会推荐的标准。随后,受试者依据不同的运动终止原因被细分为4个组(生理组,身体组,感觉组和临床组)。运动中记录主观用力感觉、血压、血乳酸浓度(BL)、摄氧量、心率和呼吸困难记分,并且连续监控12导联心电图。运动前测量血胆固醇浓度(BC)。结果显示,在运动能力方面,身体组和知觉组的运动终止原因优于临床组,但劣于生理组。患者的分布在BC为5.4mmol·L-1和BL为1.6mmol·L-1这两点出现了显著的组间差异(P<0.01或P<0.05)。在获得了安静状态下的BC和BL,病人的RET便可被预测出来,且预测具有较高的敏感性和特异性。结论:利用本研究得出的方法对RET进行预测,在心脏康复的运动实验和处方制定中,都可发挥出有益的作用。     

Italian women's television coverage and audience during the 2004 Athens Olympic Games

This study aimed at determining the amount of Italian television coverage dedicated to men's and women's sport and the number of male and female viewers during the 2004 Summer Olympic Games. AUDITEL-AGB Nielsen Media Research Italia provided the TV airtime data for the sport events broadcast, which were classified into three categories: men-only, women-only, and mixed-gender. The viewer sample was divided by age and gender and included three audience parameters: mean audience, share, and appreciation index. The last item is calculated from the program duration, audience permanence, and the share related to programs broadcast by other Italian channels. In particular, the appreciation index was used to investigate the relationship between (a) the viewer's and sport participants' gender and (b) the effect of Italian participation and expectations for sport achievement. The data showed that Italian male athletes outnumbered their female counterparts. Women's sport was allotted significantly less airtime than men's sport, but this imbalance was not proportional to the gender difference in the overall athletes' participation in the Games. Although the female audience represented 45% of the total, a significantly higher male mean audience and share were found. On the other hand, the appreciation of men's and women's sport events was balanced after equating for differences in media coverage. Moreover sport achievement might have a positive effect on the trend toward equality of gender coverage, indicating that a global multisport event such as the Olympic Games is central to communicating a national image and identity independently of the athletes' gender.     

Effect of a novel pedal design on maximal power output and mechanical efficiency in well-trained cyclists

In this study, we evaluated the effects of a novel pedal design, characterized by a downward and forward shift of the cleat fixing platform relative to the pedal axle, on maximal power output and mechanical efficiency in 22 well-trained cyclists. Maximal power output was measured during a series of short (5-s) intermittent sprints on an isokinetic cycle ergometer at cadences from 40 to 120 rev min(-1). Mechanical efficiency was evaluated during a submaximal incremental exercise test on a bicycle ergometer using continuous VO(2) and VCO(2) measurement. Similar tests with conventional pedals and the novel pedals, which were mounted on the individual racing bike of the participant, were randomized. Maximal power was greater with novel pedals than with conventional pedals (between 6.0%, s(x) = 1.5 at 40 rev min(-1) and 1.8%, s(x) = 0.7 at 120 rev min(-1); P = 0.01). Torque production between crank angles of 60 degrees and 150 degrees was higher with novel pedals than with conventional pedals (P = 0.004). The novel pedal design did not affect whole-body VO(2) or VCO(2). Mechanical efficiency was greater with novel pedals than with conventional pedals (27.2%, s(x) = 0.9 and 25.1%, s(x) = 0.9% respectively; P = 0.047; effect size = 0.9). In conclusion, the novel pedals can increase maximal power output and mechanical efficiency in well-trained cyclists.     

Do regression-based computer algorithms for determining the ventilatory threshold agree?

The determination of the ventilatory threshold has been a persistent problem in research and clinical practice. Several computerized methods have been developed to overcome the subjectivity of visual methods but it remains unclear whether different computerized methods yield similar results. The purpose of this study was to compare nine regression-based computerized methods for the determination of the ventilatory threshold. Two samples of young and healthy volunteers (n = 30 each) participated in incremental treadmill protocols to volitional fatigue. The ventilatory data were averaged in 20-s segments and analysed with a computer program. Significant variance among methods was found in both samples (Sample 1: F = 11.50; Sample 2: F = 11.70, P < 0.001 for both). The estimates of the ventilatory threshold ranged from 2.47 litres.min(-1) (71% VO2max) to 3.13 litres.min(-1) (90% VO2max) in Sample 1 and from 2.37 litres.min(-1) (67% VO2max) to 3.03 litres.min(-1) (83% VO2max) in Sample 2. The substantial differences between methods challenge the practice of relying on any single computerized method. A standardized protocol, likely based on a combination of methods, might be necessary to increase the methodological consistency in both research and clinical practice.     

Acute effects of walking on inflammatory and cardiovascular risk in sedentary post-menopausal women

Biochemical markers of inflammation are emerging as new predictors of risk of cardiovascular disease (CVD) and may alter acutely with exercise. Few studies have been conducted on the effects of walking on these markers or whether different walking intensities elicit varied effects. As there is growing interest in modifiable lifestyle factors such as walking to reduce CVD risk, these inflammatory responses warrant investigation. The aim of this study was to compare the effects of walking at 50% versus 70% of predicted maximal heart rate on C-reactive protein (CRP), plasma fibrinogen, and triglycerides in sedentary post-menopausal women. Twelve post-menopausal women (mean age 58 years, s +/-6; stature 1.62 m, s+/-0.06; body mass 66.8 kg, s +/-6.2) completed two 30-min treadmill walks in a randomized cross-over design. Fasted blood samples were taken (for the determination of plasma fibrinogen, CRP, and lipids) before, immediately after, and 1 and 24 h after exercise. Triglyceride concentrations decreased from pre-exercise to 24 h post exercise at both walking intensities (time x group interaction, P < 0.05). No significant effects were observed for plasma fibrinogen, CRP, total cholesterol, low-density or high-density lipoprotein cholesterol (time x group interaction, P > 0.05). The results of this study suggest that fasting plasma triglycerides are decreased on the morning after 30 min of brisk walking at either 50% or 70% of maximal heart rate (moderate and vigorous intensity).     

Beijing 2022 Winter Olympic Games:Commitments to science and public health

The Beijing 24th 2022 Winter Olympic Games present a unique opportunity to promote the spirit and values of the Olympic Games in relation to their impact on physical activity and global health,sports medicine,and sports performance.The 2022 Winter Olympic Games mark the 98th year since the first Winter Games were held in Chamonix,France,in 1924.The inaugural Winter Olympic Games sponsored 16 events,and 250 athletes from 16 nations participated.1 In contrast,the Beijing 2022 Winter Olympic Games will sponsor 109 events.     

Commentary on "Association of daily sitting time and leisure-time physical activity with body fat among U.S. adults"

<正>In their study,association of daily sitting time and leisure-time physical activity (LTPA) with body fat among U.S.Adults,Liao et al.¹ analyzed data from the 2011-2018 National Health and Examination Survey to examine associations between h/day sitting,meeting (or not meeting) the U.S.Physical Activity Guidelines of≥150 min/week of moderate-and vigorous-intensity LTPA,and combinations of sitting time and LTPA on totaland trunk percent body fat (BF%).     

打开科幻之门的钥匙 ——与科幻作家面对面

科幻作品缔造了一个个不同于现实的、丰富离奇的世界.那么,科幻作品与其他幻想类作品的区别是什么?科幻作家是怎么创作的?"可可豆"们怎样才能写好科幻作品呢?我们邀请到了科幻作家E伯爵为大家精彩解答.     

2024 Wheelchair Compendium of Physical Activities:An update of activity codes and energy expenditure values

Purpose:This paper presents an update of the 201 1 Wheelchair Compendium of Physical Activities designed for wheelchair users and is referred to as the 2024 Wheelchair Compendium.The Wheelchair Compendium aims to curate existing knowledge of the energy expenditure for wheelchair physical activities(PAs).Methods:A systematic review of the published energy expenditure of PA for wheelchair users was completed between 201 1 and May 2023.We added these data to the 2011 Wheelchair Compendium data that...