Kir6.2基因E23K位点多态性与耐力训练后血糖、胰岛素和VO2max改变的关系

目的探讨Kir6.2基因E23K位点多态性与耐力训练所致的血糖、胰岛素和VO2max改变间的关系.方法采用PCR-RFLP技术对214例美国各种族50至75岁男女受试者的Kir6.2位点E23K多态性进行基因型分析.受试者在专人监控下进行24周的耐力训练后,观察其E23K与血糖、胰岛素和VO2max之间的关系.结果(1)三种基因型受试者的空腹血糖、胰岛素和VO2max的基础值无显著差异;(2)24周耐力训练后,三种基因型受试者的VO2max均显著升高(P＜0.05),体重和体脂则显著下降(P＜0.05),身高体重指数(BMI)和呼吸商(RER)则在男性各基因型中显著下降(P＜0.05);(3)24周耐力训练后,三种基因型受试者的空腹胰岛素水平和曲线下面积(AUC)均显著下降(P＜0.05),但训练并未引起空腹血糖及其AUC显著变化.(4)男性EK基因型RER显著低于EE和KK基因型,女性则表现为KK基因型显著高于EE基因型.结论(1)无论E23K位点的基因型为EE、EK或KK,24周的耐力训练均可提高受试者的VO2max并降低体重、体脂、空腹胰岛素水平和AUC;(2)耐力训练对男性BMI和RER降低的影响更显著;(3)E23K多态性与RER的关系较VO2max和血糖水平更密切.     

PPARδ基因多态与有氧能力及训练敏感性的关联研究

目的探讨过氧化物酶体增殖物激活受体δ(PPARδ)基因第四外显子的单核苷酸多态(C294T)是否与有氧运动能力及训练敏感性相关联。方法对102名中国北方地区汉族男性青年进行为期18周的耐力训练(每次5000米、每周3次)。强度以个体通气无氧阈(VT)对应的心率(HRVT)为标准,前10周采用95%通气无氧阈对应的心率(HRVT±3),后8周采用105%通气无氧阈对应的心率(HRVT±3)。递增负荷运动实验测定受试者训练前后VO2max及相关指标和跑节省化时的心率(HR)、通气量(VE)和摄氧量(VO2)。采用限制性片断长度多态(PCR-RFLP)法测定PPARδ基因C294T位点。结果三种基因型的分布频率分别为CC基因型9人(0.09)、CT基因型37人(0.36)和TT基因型56人(0.55),符合Hardy-Weinberg平衡。按基因型分组后,CC基因型训练前的VO2max相对值显著性高于CT基因型和TT基因型(P<0.05);携带不同基因型群体的VO2max、跑节省化测试中的各项指标的变化率无显著性差异(P>0.05)。结论PPARδ基因第四外显子的单核苷酸C294T多态与VO2max相对值的初始值相关联,但与有氧耐力训练效果不关联。     

Caffeine has a small effect on 5-km running performance of well-trained and recreational runners

The purpose of this study was to investigate if caffeine ingestion improves 5-km time-trial performance in well-trained and recreational runners. Using a double-blind placebo-controlled design, 15 well-trained and 15 recreational runners completed two randomized 5-km time-trials, after ingestion of either 5mgkg(-1) of caffeine or a placebo. Caffeine ingestion significantly improved 5-km running performance in both the well-trained and recreational runners. In comparison to the placebo trial, the caffeine trial resulted in 1.1% (90% CI 0.4-1.6) and 1.0% (0.2-2%) faster times for the well-trained and recreational runners. Reliability testing of the recreational runners indicated a test-retest error of measurement of 1.4%. We conclude that caffeine ingestion is likely to produce small but significant gains in 5-km running performance for both well-trained and recreational runners.     

长期耐力训练对武警战士运动和静息状态血压的影响

 目的本研究结合武警部队战士训练大纲和训练实际,研究耐力性训练对武警战士血压的影响,为科学训练与监控提供基础资料.方法采用持续跑、间歇跑进行为期12周的耐力训练,测量训练前后运动和静息状态血压的变化.结果武警战士经过阶段性耐力训练后,静息状态下,SBP从(115.15±9.26)mmHg降为(110.82±8.84)mmHg,平均下降了4.33mmHg(P＜0.01);DBP下降了1.6 mmHg(P＞0.05).一次性耐力运动负荷的测试结果表明,实验后运动即刻SBP、DBP和实验前相比分别下降了4.44mmHg和2.18 mmHg(均为P＞0.05).恢复期5 min的比较结果为:SBP分别为(128.18±8.91)mmHg和(122.56±5.07)mmHg(P＜0.05);DBP分别为(72.18±5.41)mmHg和(71.43±4.81)mmHg(P＞0.05).结论长期耐力训练对武警战士运动和静息状态血压产生有利的影响.     

The associations between training load and baseline characteristics on musculoskeletal injury and pain in endurance sport populations: A systematic review

Objectives

To determine the associations between training load, baseline characteristics (e.g. age or previous injury) and rate of musculoskeletal injury and/or pain specifically within an Endurance Sporting Population (ESP).

锌对小鼠在高温环境下机体耐力的影响(论著)

目的：观察锌对热应激小鼠机体耐力的影响。方法：进行３种试验，即游泳试验、耐缺氧试验和高温致死试验。作各种试验的小鼠分别再分为高锌组、中锌组和低锌组，并喂以相应的高、中、低锌饲料２１天（高温致死试验为１４天）。每日光暗节律各１２小时，自由摄食与饮水，同时观察动物活动、皮毛、摄食及体重情况。游泳试验水温为４０．０±０．２℃，记录小鼠入水游泳至沉底死亡的时间。耐缺氧试验在高温室（干球３９℃、湿球３４℃）内进行，记录小鼠在腊封瓶内的存活时间。高温致死试验在ＤＬ－３０１Ａ型调温调湿箱（干球４６℃，湿球４１℃）内进行，观察３０分钟内的各组动物死亡数。结果：①高锌组小鼠游泳时间显著长于中、低锌组；②高锌组小鼠耐缺氧时间显著长于低锌组；③高锌组小鼠的３０分钟致死率显著低于低锌组。结论：适量补锌可以增强小鼠在高温环境下的热耐受能力     

Glucose‐fructose likely improves gastrointestinal comfort and endurance running performance relative to glucose‐only

This study aimed to determine whether glucose‐fructose (GF) ingestion, relative to glucose‐only, would alter performance, metabolism, gastrointestinal (GI) symptoms, and psychological affect during prolonged running. On two occasions, 20 runners (14 men) completed a 120‐min submaximal run followed by a 4‐mile time trial (TT). Participants consumed glucose‐only (G) or GF (1.2:1 ratio) beverages, which supplied ～ 1.3 g/min of carbohydrate. Substrate use, blood lactate, psychological affect [Feeling Scale (FS)], and GI distress were measured. Differences between conditions were assessed using magnitude‐based inferential statistics. Participants completed the TT 1.9% (?1.9; ?4.2, 0.4) faster with GF, representing a likely benefit. FS ratings were possibly higher and GI symptoms were possibly‐to‐likely lower with GF during the submaximal period and TT. Effect sizes for GI distress and FS ratings were relatively small (Cohen's d = ～0.2 to 0.4). GF resulted in possibly higher fat oxidation during the submaximal period. No clear differences in lactate were observed. In conclusion, GF ingestion – compared with glucose‐only – likely improves TT performance after 2 h of submaximal running, and GI distress and psychological affect are likely mechanisms. These results apply to runners consuming fluid at 500–600 mL/h and carbohydrate at 1.0–1.3 g/min during running at 60–70% VO_2peak.