间歇性低氧训练对大鼠骨骼肌相关代谢及c-fos表达的影响

采用间歇性低氧复合常氧训练的方法,下高原调整后以25m/min的速度一次性力竭,紫外分光光度法测定大鼠骨骼肌匀浆液中SOD、MDA、SDH、CCO指标变化,免疫组织化学ABC法测定骨骼肌c-fos基因表达.结果表明：IHT组能明显提高大鼠抗氧化和清除自由基以及有氧代谢的能力,降低了c-fos表达,有效改善了大鼠对中等强度耐力运动的适应能力,旨在为运动员间歇性低氧训练后平原耐力参赛提供参考.     

少儿训练营养特点初探

少儿训练是运动员一生的启蒙阶段，基础建立得是否扎实、牢固，不仅取决于科学训练，而且还取决于训练中的营养供应。实践已经证明，在少儿时期，营养是发育的基础，也是训练的基础，科学的营养是其成材的关键。     

细胞凋亡与动脉粥样硬化

从细胞凋亡与动脉粥样硬化关系的角度阐述了细胞凋亡的证据及细胞凋亡的特点，探讨了动脉粥样硬化中细胞凋亡的发生机制，指出细胞凋亡是促成动脉粥样硬化的重要因素。     

Is high soleus muscle activity during the stance phase of the running cycle a potential risk factor for the development of medial tibial stress syndrome? A prospective study

ABSTRACT

To assess the impact of lower-leg muscle activity during the stance phase of running on the development of medial tibial stress syndrome (MTSS), in 123 healthy participants (18.2 ± 0.8 years), dynamic and static foot posture, and soleus and tibialis anterior muscle activity during the stance phase of running were measured before a 17-week track- and field-course. After the course, MTSS was identified in 20.5% of the participants. MTSS participants had a higher body mass (ES = 1.13), body mass index (BMI) (ES = 1.31), lower previous vigorous physical activity level (ES = 0.84) and VO_2max (ES = 0.61), greater dynamic foot pronation (ES = 0.66), higher soleus peak EMG amplitude during the absorption (ES = 0.60) and propulsion phases (ES = 0.56) of running, and a history of MTSS (OR = 6.38) (p < 0.05). Stepwise logistic regression showed BMI, dynamic foot index, soleus peak EMG amplitude during propulsion, MTSS history and previous vigorous physical activity were predictors of MTSS. The model predicted 96.6% of the healthy participants and 56.5% of the MTSS participants and correctly classified 88.4% of overall cases. Coaches and sports-medicine professionals that screen for injury risk should consider adopting a comprehensive evaluation that includes these parameters.     

Montmorency tart cherry (Prunus cerasus L.) supplementation accelerates recovery from exercise-induced muscle damage in females

Abstract

Tart Montmorency cherry concentrate (MC) has been reported to attenuate the symptoms of exercise-induced muscle damage (EIMD) and to accelerate exercise recovery, which has been attributed to its high anti-inflammatory and antioxidant properties. Although these data are promising, there are no data regarding exclusively female populations. Therefore, the aim of this investigation was to examine the efficacy of MC on recovery following EIMD in females. In a randomised, double-blind, placebo-controlled study, twenty physically active females (mean?±?SD age 19?±?1?y; stature 167?±?6?cm; body mass 61.4?±?5.7?kg) consumed MC or a placebo (PL) for eight days (30?mL twice per day). Following four days of supplementation, participants completed a repeated-sprint protocol and measures of muscle soreness (DOMS), pain pressure threshold (PPT), limb girth, flexibility, muscle function, and systemic indices of muscle damage and inflammation were collected pre, immediately post (0?h) and 24, 48 and 72?h post-exercise. Time effects were observed for all dependent variables (p?<?0.05) except limb girth and high sensitivity C-reactive protein. Recovery of countermovement jump height was improved in the MC group compared to PL (p?=?0.016). There was also a trend for lower DOMS (p?=?0.070) and for higher PPT at the rectus femoris (p?=?0.071) in the MC group. The data demonstrate that MC supplementation may be a practical nutritional intervention to help attenuate the symptoms of muscle damage and improve recovery on subsequent days in females.     

Ca^2＋对离体骨骼肌收缩性的影响

目的：探讨钙离子对蟾蜍离体腓肠肌收缩性的影响。方法：把剥制好的离体腓肠肌标本先浸泡在任氏液中,用LMS-2B型二道生理记录仪记录最适刺激下的单收缩曲线;然后换上不同浓度的钙离子溶液浸泡10min,记录单收缩曲线。分别测定单收缩的最大收缩幅度、收缩能量、抑制率。结果表明,低浓度的Ca^2＋溶液对蟾蜍离体腓肠肌收缩能力具有显著的促进作用,而高浓度的Ca^2＋溶液对蟾蜍离体腓肠肌的收缩能力具有显著的抑制作用。     

Exercise Professionals Improve Their Poor Skills in Contracting Pelvic-Floor Muscles: A Randomized Controlled Trial

ABSTRACT

A quick, well-timed pelvic-floor muscle contraction during physical effort is recommended for active women to prevent urine leakage. Purpose: We address two research questions: how well do future female exercise professionals contract the pelvic-floor muscles, and whether the biofeedback session is necessary to train them to contract pelvic-floor muscles? Method: Participants were 84 nulliparous future exercise professionals (age 23 ± 3 years, mean ± SD), randomly allocated into biofeedback (n = 27), usual-advice (n = 26), and control (no advice, n = 21) groups. Contraction of pelvic-floor muscles on a 4-point scale (1 = incorrect through 4 = correct) was assessed in all groups by surface electromyography (sEMG) with a vaginal probe before and after 6 weeks of intervention. Results: In pretest, almost one in five participants (17%) could not activate the pelvic floor and less than half of them (45%) presented correct technique. The technique score for the three groups was 3.1 ± 1.1 (mean ± SD). After training, both intervention groups presented better technique score by 0.6 (90% confidence limits ± 0.5) relative to the control group, and two-thirds (65%) of the intervention groups presented the correct technique. Conclusions: Future exercise professionals displayed poor skills in contracting pelvic-floor muscles. Both training interventions (with and without biofeedback) were effective for this study group.     

Beneficial Effects of Inspiratory Muscle Training Combined With Multicomponent Training in Elderly Active Women

ABSTRACT

Purpose: This study aims to analyze changes in Maximum Inspiratory Pressure (MIP), lung function, cardiorespiratory fitness, and blood pressure, in 10 healthy active elderly women, following 7 weeks of inspiratory muscle training (IMT) combined with a multicomponent training program (MCTP). The association among these health parameters, their changes after training (deltas), and the influence of MIP at baseline (MIP_pre) are also considered. Methods: IMT involved 30 inspirations at 50% of the MIP, twice daily, 7 days a week, while MCTP was 1 hr, twice a week. MIP, lung function (FVC, FEV₁, FEV₁/FVC, FEF_25-75%, PEF), 6MWT, and blood pressure (SBP, DBP), jointly with body composition, were assessed before and after the intervention. Results: Seven weeks were enough to improved MIP (p = .019; d = 1.397), 6MWT (p = .012; d = .832), SBP (p = .003; d = 1.035) and DBP (p = .024; d = .848). Despite the high physical fitness (VO₂ peak: M = 23.38, SD = 3.39 ml·min·Kg^?1), MIP_pre was low (M = 39.00, SD = 7.63 cmH₂O) and displayed a significant negative correlation with ΔMIP_pre-post (r = ?.821; p < .004), showing that women who started the intervention with lower MIP achieved higher improvements in inspiratory muscle strength after training. Conclusions: No significant changes in spirometric parameters may signal that lung function is independent of early improvements in inspiratory muscles and cardiorespiratory fitness. Absence of correlation between physical fitness and respiratory outcomes suggests that being fit does not ensure cardiorespiratory health in active elderly women, so IMT might be beneficial and should supplement the MCTP in this population.     

针刺对急性骨骼肌钝挫伤大鼠肌卫星细胞增殖的影响

目的:观察针刺对急性骨骼肌钝挫伤大鼠卫星细胞增殖的影响。方法:将采用打击装置造成后下肢腓肠肌钝挫伤的大鼠随机分为即刻组、针刺治疗组、自然愈合组。针刺治疗组采用阿是穴针刺疗法,自然愈合组不治疗。结果:针刺治疗组肌卫星细胞核数在大鼠伤后第2天时达高峰,而自然愈合组在伤后第4天达高峰,之后呈下降趋势。在损伤后第1天、第2天、第4天,针刺治疗组大鼠肌卫星细胞核数目均比自然愈合组多,且在损伤后第2天显著高于自然愈合组。结论:大鼠骨骼肌损伤后,针刺能促进肌卫星细胞的增殖并促使活跃期提前出现,促进肌肉再生,加速损伤愈合的进程。     

有氧运动在改善胸主动脉平滑肌反应性中的KATP通道机制

目的:探讨有氧运动对大鼠胸主动脉平滑肌细胞KATP通道的影响。方法:Wistar大鼠,雄性,2月龄,共20只,随机分为2组,安静对照组和有氧运动组,运动组进行8周递增速度跑台运动。8周后,在体实验各组选取5只,进行股动静脉插管手术,术后恢复1 d后,测定注射KATP通道阻断剂glibenclamide后的血压和心率;剩余10只大鼠进行离体实验,大鼠开胸腔取胸主动脉,去内皮,制备成血管环,分别给予KATP通道阻断剂glibenclamide和KATP通道开放剂pinacidil等药物刺激,观察两种药物所引起的血管反应性变化。结果:1)运动组静脉注射KATP通道阻断剂glibenclamide(20 mg/kg)所引起的血压升高幅度显著增大,心率显著下降。2)glibenclamide(3×10-5M)可诱发大鼠血管张力增加,运动后其升高幅度显著高于安静组。3)有氧运动组pinacidil诱导的血管舒张反应显著增大。结论:有氧运动在改善胸主动脉血管平滑肌反应性的作用中,KATP通道活性的增强是重要机制之一。