鞍山市高校教师亚健康现状调查及有氧运动对策

为了解鞍山市高校教师亚健康现状,对鞍山某两所高校406名教师进行了问卷调查.结果表明：78.7%的教师知道亚健康,但对亚健康知识了解得不多;83.3%的教师达不到健康10项标准;78.3%的高校教师休息时间晚,睡眠不足,神经衰弱;57.1%的高校教师工作量大,过度劳累,身心透支;34.5%的高校教师工作、家庭压力大;30.4%的高校教师饮食无规律,不吃早餐、偏食或暴饮暴食;84.5%的高校教师没有体育锻炼计划,基本上不参加体育锻炼.大多数高校教师处于亚健康状态,应引起足够重视.有氧运动是预防和消除亚健康的最佳手段,希望能够为提高高校教师健康水平提供可资参考的依据.     

有氧运动与补充茶多酚对高脂膳食大鼠糖脂代谢及炎症因子TNF-α和IL-6的影响

目的:研究有氧运动和补充茶多酚对高脂膳食大鼠糖脂代谢及炎症因子TNF-α和IL-6的影响,并探讨炎症因子TNF-α和IL-6在营养性肥胖所致的糖脂代谢异常及胰岛素抵抗中的作用。方法:3周龄SD雄性大鼠50只,随机分为普通膳食对照组(C组)、高脂膳食对照组(H组)、有氧运动组(HE组)、茶多酚组(HT组)和综合干预组(HET组)。C组以普通饲料饲养,其余各组均以高脂饲料饲养;HE组和HET组大鼠进行为期8周的无负重游泳训练;HT组和HET组大鼠每周6 D以1 g/kg体重剂量的茶多酚灌胃。8周后测试大鼠糖脂代谢相关指标及炎症因子TNF-α和IL-6。结果:与C组相比,H组大鼠体重显著增加,血清GLU、TC、TG和FINS显著增加,血清和脂肪组织中TNF-α和IL-6显著增加;与H组相比,HE组、HT组和HET组大鼠上述指标有所降低,而以HET组降低幅度最为显著。结论:有氧运动和补充茶多酚均可改善高脂膳食引起的糖脂代谢异常和胰岛素抵抗,且以联合应用有氧运动和补充茶多酚的综合干预措施效果最为显著。有氧运动和补充茶多酚对高脂膳食所致糖脂代谢异常和胰岛素抵抗的改善作用与其抑制脂肪组织炎症因子TNF-α和IL-6的表达和分泌密切相关。     

体能主导类耐力性项群运动性疲劳特征与消除措施的研究

从能量代谢的视角分析体能主导类耐力性项群疲劳的特征,指出能源物质的消耗、代谢产物乳酸堆积和pH下降、体液减少和无机盐丢失是该项群发生疲劳的主要原因,并针对性地提出疲劳恢复的主要措施．体能主导类耐力性项群的训练和比赛由于运动强度、运动时间的不同,产生疲劳的机制也不尽相同,只有真正了解体能主导类耐力性项群疲劳产生的原因,才能正确、有针对性地消除运动性疲劳,提高运动成绩．     

Effect of tapering period on plasma hormone concentrations,mood state,and performance of elite male cyclists

Abstract

In this study, we investigated the effect of 1- and 3-week tapering periods on concentrations of plasma testosterone (T), cortisol (C), T/C ratio, mood state, and performance in elite male cyclists. After 8 weeks of progressive training, cyclists were randomly assigned to a control group (n=12) who continued performing intense training for a further 3 weeks, or a taper group (n=12) who continued with a 50% reduction in training volume. Blood testosterone and cortisol concentrations were assayed and the T/C ratio calculated from analysis obtained via standard ELISA. Mood state was determined using the Profile of Mood States (POMS) questionnaire. All data were collected immediately after a 40-km time-trial performed before, during, and after the 8-week training protocol and after the 1- and 3-week tapering/training periods. In the taper group, 40-km time-trial time decreased significantly (P<0.01) and equally for both the 1- and 3-week taper periods relative to the control group. There were significant elevations in T/C ratio (P<0.001) and reductions in cortisol concentrations and POMS scores in the taper group relative to the control groups at the end of both the 1- and 3-week tapering periods. Hence, taper periods are effective in improving performance and mood state and elevating the blood T/C ratio.     

Exercise and bone

Abstract

The aim of this study was to examine the interrelationship between aerobic fitness, body composition, and physical activity in 9- and 15-year-olds. The 270 participants were randomly selected from 18 primary and secondary schools in Iceland. Aerobic fitness was assessed by a graded exercise test on a bicycle ergometer. Body composition was estimated via: logarithm of sum of four skinfolds (log_e skinfolds), waist adjusted for height, and body mass index (BMI). Physical activity was measured with Actigraph activity monitors using total activity each day as the physical activity variable. Aerobic fitness was chosen as the primary outcome variable, body composition as the secondary variable, and physical activity as the tertiary variable. All the full models explained a similar proportion of fitness variance for both age groups (45–65%). Among the 15-year-olds, log_e skinfolds explained a significantly larger proportion of the fitness variance (54%) than waist adjusted for height (29%) and BMI (15%), but all the body composition variables explained a similar proportion of the fitness variance (35–42%) among the 9-year-olds. Physical activity explained a smaller proportion (0%) of the unadjusted variance in fitness for the 9-year-olds than for the 15-year-olds (19%). This group difference became non-significant (0% vs. 4%) when adjusting for log_e skinfolds but remained significant when controlling for waist adjusted for height (0% vs. 15%) and BMI (0% vs. 18%). Gender differences in aerobic fitness after puberty can largely be explained by gender differences in log_e skinfolds and physical activity. In conclusion, the interrelationship between fitness, body composition, physical activity, and gender is not the same among 9- and 15-year-olds.     

Endurance athletes' coping function use during competitive suffering episodes

Abstract

Endurance athletes who realise that they are falling short of important personal goals during competition are expected to experience competitive suffering. As a negative affective state with implications for performance and personal experiences, it is important to understand how endurance athletes cope with competitive suffering. Thus, the purpose of this study was to investigate differences in athletes' momentary coping function use over time during a competitive suffering episode. Twenty-six runners (mean age: 35.8 years) completed a 5-km running time trial that evoked an experience of competitive suffering using false failure-oriented feedback. Momentary assessments of goal attainment feelings and coping function use were completed immediately following the running time trial using video-mediated recall. Pooled time series analysis was used to predict coping function use across several points in time (i.e. earlier and later stages of a competitive suffering episode) and at different ratings of goal attainment feelings. Analyses revealed that negative feelings about goal attainment moderately predicted problem-focused coping use, and strongly predicted emotion-focused coping use. Although it was not predicted by goal attainment feelings, avoidance coping use was decreased over time throughout suffering episodes. Overall, this study supports propositions that the coping process is continually adapted to competitive demands and identifies the roles of distinct coping functions within the total coping effort.     

Hydration kinetics and 10-km outdoor running performance following 75% versus 150% between bout fluid replacement

Abstract

Current American College of Sports Medicine (ACSM) guidelines recommend replacing 150% of sweat losses between training bouts separated by ≤12 hours, but little evidence exists concerning the implications of this strategy for runners. Participants (n = 13) in this study replaced 75% (1637 ± 372 mL) or 150% (3099 ± 850 mL) of sweat losses following an outdoor evening run (～75 minutes; Wet-bulb-globe temperature (WBGT) = ～27°C) and consumed a standardised evening meal and breakfast before completing an outdoor (WBGT = ～23°C) 10-km time-trial the following morning. Urine was collected between runs and urine specific gravity (USG) was assessed pre-run. Significant differences were found in pre-run body mass (75% = 69.6 ± 9.2; 150% = 70.1 ± 9.3 kg; P = 0.02) and USG (75% = 1.026 ± 0.005; 150% = 1.014 ± 0.007; P < 0.001). Heart rate during 10-km run (168 ± 14 versus 168 ± 12 beats min^?1) and post-run intestinal temperature (39.08 ± 0.52 versus 39.00 ± 0.70 °C) did not differ for 75% and 150%, respectively, despite an ～3% performance improvement (75% = 47.28 ± 6.64; 150% = 45.93 ± 6.04 minutes; P = 0.001) due to a faster pace in the second half of the run with 150% replacement. Session rate of perceived exertion (RPE) was lower (P = 0.02) during 150% (7.5 ± 1.3) versus 75% (8.4 ± 0.9). Reluctant drinkers potentially hinder training quality between evening and morning runs in the heat, but copious urine production and difficulty in consuming recommended fluid volumes suggest fluid replacement <150% may be more ideal.     

The menstrual cycle and its effect on the immune status of female endurance runners

Twenty highly trained, eumenorrhoeic female endurance runners were studied over three consecutive menstrual cycles. Average training distance per week, total years training and mood states were recorded throughout the three cycles. Salivary progesterone and menstrual cycle diaries were recorded over the first two cycles to identify luteal phase onset and the presence of any menstrual irregularities. Saliva samples were collected daily over the third cycle for analysis of immunoglobulin A (IgA) concentration and secretion and saliva flow rate. Twoway analysis of variance (ANOVA) revealed no significant differences in mood states across the phases of the menstrual cycle ( P > 0.05). Training logs indicated that training did not alter throughout the 3 month study. One-way ANOVArevealed no significant differences in IgA concentration ( P = 0.92), secretion rate ( P = 0.84) or saliva flow rate ( P = 0.95) across the phases of the menstrual cycle. Pearson's product-moment correlation revealed no relationship between IgA concentration and progesterone between the phases of the cycle ( r = 0.39). We conclude that, in ovulatory female endurance runners whose physical and emotional stress are stable, IgA concentration is not significantly affected by fluctuations in progesterone during the menstrual cycle.     

The multi-stage fitness test as a predictor of endurance fitness in wheelchair athletes

Abstract

The aims of this study were two-fold: (1) to consider the criterion-related validity of the multi-stage fitness test (MSFT) by comparing the predicted maximal oxygen uptake ([Vdot]O_2max) and distance travelled with peak oxygen uptake ([Vdot]O_2peak) measured using a wheelchair ergometer (n = 24); and (2) to assess the reliability of the MSFT in a sub-sample of wheelchair athletes (n = 10) measured on two occasions. Twenty-four trained male wheelchair basketball players (mean age 29 years, s = 6) took part in the study. All participants performed a continuous incremental wheelchair ergometer test to volitional exhaustion to determine [Vdot]O_2peak, and the MSFT on an indoor wooden basketball court. Mean ergometer [Vdot]O_2peak was 2.66 litres · min^?1 (s = 0.49) and peak heart rate was 188 beats · min^?1 (s = 10). The group mean MSFT distance travelled was 2056 m (s = 272) and mean peak heart rate was 186 beats · min^?1 (s = 11). Low to moderate correlations (ρ = 0.39 to 0.58; 95% confidence interval [CI]: ?0.02 to 0.69 and 0.23 to 0.80) were found between distance travelled in the MSFT and different expressions of wheelchair ergometer [Vdot]O_2peak. There was a mean bias of ?1.9 beats · min^?1 (95% CI: ?5.9 to 2.0) and standard error of measurement of 6.6 beats · min^?1 (95% CI: 5.4 to 8.8) between the ergometer and MSFT peak heart rates. A similar comparison of ergometer and predicted MSFT [Vdot]O_2peak values revealed a large mean systematic bias of 15.3 ml · kg^?1 · min^?1 (95% CI: 13.2 to 17.4) and standard error of measurement of 3.5 ml · kg^?1 · min^?1 (95% CI: 2.8 to 4.6). Small standard errors of measurement for MSFT distance travelled (86 m; 95% CI: 59 to 157) and MSFT peak heart rate (2.4 beats · min^?1; 95% CI: 1.7 to 4.5) suggest that these variables can be measured reliably. The results suggest that the multi-stage fitness test provides reliable data with this population, but does not fully reflect the aerobic capacity of wheelchair athletes directly.     

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s :age 23 +/- 4 years;body mass 69.7 +/- 9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23 +/- 4 years; body mass 72.7 +/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO 2max , running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol.l -1 ; and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO 2max , running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol.l -1 or the lactate minimum speed.In the training group, there was a significant increase in VO 2max (from 47.9 +/- 8.4 to 52.2 +/- 2.7 ml.kg -1 .min -1 ), running speed at the maximal lactate steady state (from 13.3 +/- 1.7 to 13.9 +/- 1.6 km.h -1 ), running speed at the lactate threshold (from 11.2 +/- 1.8 to 11.9 +/- 1.8 km.h -1 ) and running speed at a blood lactate concentration of 3 mmol.l -1 (from 12.5 +/- 2.2 to 13.2 +/- 2.1 km.h -1 ) (all P ? 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0 +/- 0.7 to 10.9 +/- 1.7 km.h -1 ). The results demonstrate that the lactate minimum speed,when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.