Cross-Validation of the Revised Motivation for Physical Activity Measure in Active Women

Abstract

The five different training methods used in this study consisted of various proportions of swimming and of weight training exercises. Sixty subjects were divided into five equated groups. Each group was exposed to a different treatment over a period of six weeks. Tests of swimming speed were administered at the beginning of the experiment, and at the end of each week. All five treatments resulted in significant swimming improvements, but none of the treatments were significantly more effective than the other treatments.     

The effect of a resistance training programme on the grab,track and swing starts in swimming

The aim of this study was to establish the effectiveness of a resistance training programme, designed to improve vertical jumping ability, on the grab, swing and rear-weighted track starts in swimming. Twenty-three female non-competitive swimmers participated (age 19.9 +/- 2.4 years; mean +/- s). The diving techniques were practised weekly for 8 weeks. The participants were randomly assigned to a control group (n = 11) or a resistance-training group (n = 12), which trained three times a week for 9 weeks. The tests before and after the training programme involved performing each dive technique and six dry-land tests: two countermovement jumps (with and without arms), two isokinetic squats (bar speeds of 0.44 and 0.70 rad x s(-1)) and two overhead throws (with andwithout back extension). A repeated-measures multivariate analysis of variance was used to show that resistance training improved performance in the dry-land tests (P < 0.0001). No significant improvements due to training were found for any temporal, kinematic or kinetic variables within the grab or swing starts. Significant improvements (P < 0.05) were found for the track start for take-off velocity, take-off angle and horizontal impulse. The results suggest that the improved skill of vertical jumping was not transferred directly to the start, particularly in the grab technique. Non-significant trends towards improvement were observed within all starts for vertical force components, suggesting the need to practise the dives to retrain the changed neuromuscular properties.     

Identification of Accelerometer Nonwear Time and Sedentary Behavior

Abstract

This study was designed to investigate the swimming endurance trainability of smokers as compared to nonsmokers. Nonsmokers (N = 47) and smokers (N = 34) of college age were selected from intermediate swimming classes and timed while swimming distances of 100 yd. and 200 yd. prior to participation in an 8-week training program. After 4 weeks of training, swimming times were again recorded for these same distances. At the end of eight weeks, swimming times were taken for distances of 100, 200, and 400 yards. The mean changes of both smokers and nonsmokers during the pretraining to 4-week period, the 4-week to 8-week period, and the pretraining to 8-week period were all significant at the .05 level. However, no significant differences were found between the mean swimming times of smokers and nonsmokers for any of the pretraining, 4-week, or 8-week distances.     

不同游泳运动对大鼠血清MDA、SOD、T-AOC的影响

研究目的是探讨不同持续时间和运动频率的游泳运动对大鼠血清MDA、SOD、T-AOC的影响。将2月龄雄性SD大鼠分为安静对照组、运动1h(6次/周)组、运动2h(6次/周)组和运动1h(3次/周)组,运动组进行了14周无负重游泳训练。运动后分别测定了血清MDA、SOD和T-AOC。结果表明,运动后大鼠血清MDA的变化与运动持续时间和频率有关,每周运动6次的大鼠血清MDA含量下降,而每周运动3次MDA含量没有变化;运动后大鼠血清SOD活性没有变化,但是SOD/MDA有升高的趋势;运动各组血清T-AOC的浓度均升高。提示长期适量的游泳运动,可以提高血清T-AOC,从而降低MDA含量,提高SOD/MDA比值,有利于氧自由基的清除。     

Does a 4-week training period with hand paddles affect front-crawl swimming performance?

ABSTRACT

This study investigated the effects of a 4-week training with hand paddles (HPD) on front-crawl swimming performance (SP), clean swimming speed (SPEED), stroke rate (SR), stroke length (SL) and tethered force (TF). Twenty swimmers (10 men and 10 women) were paired according to performance and gender, and were randomly assigned to control (CON, 22.4 ± 2.3 years) or HPD (21.8 ± 1.9 years) groups. During 4 weeks both groups performed the same training, except for a sprint training set (3 times/week, 10 × 10 strokes all-out, 1-min rest) completed with (HPD = 320 cm²) and without (CON) paddles. Afterwards, both groups performed the same training over a 2-week taper period. SP, SPEED, SR, SL and TF were assessed before (PRE) and after the 4-week period (POST), after the first (T1) and second taper weeks (T2). Swimmers rated their perceived exertion for the sprint training set (RPE_TS) and the training session for determining internal training load (ITL). SP, SPEED, SR, SL and TF did not change from PRE to POST, T1 and T2. ITL and RPE_TS were not different between groups. Training 4 weeks with HPD does not affect swimming performance, so the use of HPD remains unsupported in such period.     

Biomechanical analysis of the grab, track and handle swimming starts: an intervention study

This study examined the grab, track and handle swimming racing starts by elitelevel swimmers. Videography was used to analyse these starts before and after a period of dive start practice. Participants underwent 2-4 sessions weekly until 14 +/- 2 practice sessions were completed. Practice sessions comprised 5 grab starts (preferred technique) and 10 handle starts; or 5 grab starts and 10 track starts. The performance criterion measure was time to 10 m. Reaction, movement, block and flight times, flight distance, and the centre of mass at the set position were measured. No significant differences between dive groups in time to 10 m were revealed pre- or post-training. The training period further exaggerated the differences in centre of mass positions in the set position between the three techniques. The handle start revealed a significant change forward in the centre of mass that allowed for decreased movement and block times. The training period improved 10 m, reaction, movement, block and flight times irrespective of the technique used. Hence, regular dive start practice significantly improved the start performances of elite swimmers. Coaches should consider including regular dive practice sessions of approximately 15 minutes to improve dive start performances.     

运动对骨骼肌线粒体通透性转换孔及细胞凋亡的影响

目的观察耐力训练和一次性力竭运动对大鼠骨骼肌线粒体通透性转换孔(mitochondrial permeability transi-tion pore,MPTP)相关因素及细胞凋亡的影响。方法 24只大鼠随机分为3组:对照组(C组)、耐力训练组(T组)和一次性力竭组(E组)。T组进行无负重游泳训练,6次/周,共6周,训练时间从每天45 min逐渐增加到90 min;E组正常笼内饲养6周后进行一次力竭性游泳运动。通过紫外分光光度仪检测MPTP的开放;Western blot检测细胞色素c(Cyt c)的释放;RT-PCR检测Bcl-2和Bax mRNA;双光束紫外分光光度仪检测线粒体Ca2+的转运。结果与对照组相比:(1)T组线粒体吸光度值和Ca2+的转运量无显著性变化,Cyt c的释放量与Bax mRNA的表达显著减少,Bcl-2 mRNA的表达显著增加;(2)E组线粒体吸光度值显著减少,Cyt c释放量及Ca2+转运量显著增加,Bcl-2mRNA表达显著下降,Bax mRNA表达显著增强。结论 耐力运动可能通过上调Bcl-2/Bax基因表达,减少Cyt c释放,稳定MPTP开放,从而减少细胞凋亡;一次性力竭运动可能通过下调Bcl-2/Bax基因表达,MPTP异常开放,增加Cyt c和Ca2+释放,促进细胞凋亡。     

Melatonin administration does not alter muscle glycogen concentration during recovery from exhaustive exercise in rats

Abstract

The purpose of this study was to investigate the effect of melatonin administration on muscle glycogen concentration during recovery after exhaustive swimming exercise in sedentary and trained rats. Male Wistar rats were assigned to one of four groups: sedentary control (C), sedentary melatonin-injected (M), exercise-trained (T), and trained and melatonin-injected (MT) groups. Exercise-trained groups were subjected to six weeks of swimming exercise. All rats completed an exhaustive swimming exercise. Two daily subcutaneous injections of melatonin at a dose of 3 mg·kg^?1 were given to the rats in the M and MT groups immediately after the exhaustive exercise. Plasma melatonin, glucose and lactate concentrations, and glycogen concentrations of the soleus and epitrochlearis muscle tissues were measured after exhaustive exercise. Plasma lactate concentration was significantly lower in the T and MT groups than in the C group. Plasma melatonin concentration was higher in the supplemented groups than in the C group. Plasma glucose concentration was significantly higher in the T and MT groups than in the C group. Both epitrochlearis and soleus muscle glycogen concentrations were higher in the trained groups than in the C group. In conclusion, although exercise training results in improvement in muscle glycogen, exogenous melatonin administration after exhaustive exercise did not restore the glycogen concentrations in fast- or slow-twitch muscle tissues.     

星形偏移平衡测试在评价优秀蹼泳运动员核心训练效果中的应用

通过采用8点星形偏移平衡测试来评价核心训练对优秀蹼泳运动员动态平衡能力的作用。以国家蹼泳队24名优秀蹼泳运动员为研究对象,随机分为两组:核心训练组和传统训练组。对两组进行为期8周,每周4次,每次50min的运动训练,核心训练组进行以S-E-T悬吊训练为主,瑞士球和其他垫上训练为辅的核心训练,传统训练组进行"V"字起等传统的蹼泳腰腹训练。在8周的实验前后进行SEBT测试,检验受试者动态平衡稳定能力的变化。研究结果表明,相较于传统蹼泳腰腹训练,8周的核心训练更能显著提高优秀蹼泳运动员的前庭觉、躯体感觉、视觉、中枢神经系统的调控、肌肉力量、抗外部干扰、行动的敏捷等之间的协调能力,从而提高了机体的平衡稳定能力,具有传统力量训练不可比拟的优势。动态的星形偏移平衡测试能较全面地反映机体对神经肌肉的控制能力、下肢力量、身体活动范围。     

Effects of Two Systems of Weight Training on Circulorespiratory Endurance and Related Physiological Factors

Abstract

Three groups, two experimental and one control, consisting of 20 college freshmen in each group, were tested doing moderate and all-out exercise on a bicycle ergometer. Selected physiological responses and the circulorespiratory endurance times were measured. An eight-week training period followed during which the experimental groups participated in weight-training programs and the control subjects in archery or bait casting. After training, the tests were again administered.

Though there was an indication of improved circulorespiratory responses by the weight-training groups following training, statistical treatment of the data revealed no significant differences among the three groups in their responses to exercise.     

Influence of short-term inertial training on swimming performance in young swimmers

The aim of this study was to evaluate the influence of dry-land inertial training (IT) on muscle force, muscle power, and swimming performance. Fourteen young, national-level, competitive swimmers were randomly divided into IT and control (C) groups. The experiment lasted four weeks, during which time both groups underwent their regular swimming training. In addition, the IT group underwent IT using the Inertial Training Measurement System (ITMS) three times per week. The muscle groups involved during the upsweep phase of the arm stroke in front crawl and butterfly stroke were trained. Before and after training, muscle force and power were measured under IT conditions. Simultaneously with the biomechanical measurements on the ITMS, the electrical activity of the triceps brachii was registered. After four weeks of training, a 12.8% increase in the muscle force and 14.2% increase in the muscle power (p?<?.05) were noted in the IT group. Moreover, electromyography amplitude of triceps brachii recorded during strength measurements increased by 22.7% in the IT group. Moreover, swimming velocity in the 100?m butterfly and 50?m freestyle improved significantly following the four weeks of dry-land IT (?1.86% and ?0.76%, respectively). Changes in the C group were trivial. Moreover, values of force and power registered during the ITMS test correlated negatively with the 100?m butterfly and 50?m freestyle swimming times (r value ranged from ?.80 to ?.91). These results suggest that IT can be useful in swimming practice.     

Effect of induced alkalosis on swimming time trials.

Previous studies have shown that sodium bicarbonate ingestion prior to exercise may improve performance during repeated (interval) bouts. To examine the practical implications of such findings, seven collegiate swimmers participated in simulated swim competitions of multiple events following sodium bicarbonate (B) ingestion, placebo (P) ingestion and control (C--no ingestion) treatments. Each swimmer reported to the laboratory 1 h prior to the simulated competitions (72 h apart) and was randomly assigned to one of the three experimental treatments. Competition consisted of one relay (100 yards; 91.4 m) and two individual (200 yards; 182.8 m) swimming events with 20 min rest between events. Analysis of variance (ANOVA) with repeated measures revealed no significant differences in performance times as a result of the three treatments (P greater than 0.05). The results suggest that sodium bicarbonate ingestion prior to swim competition consisting of significant rest intervals between events is not an ergogenic procedure.     

Audio,Visual, and Audio-Visual Instruction with Mental Practice in Developing the Forehand Tennis Drive

Abstract

The effectiveness of mental practice was studied when combined with three variables of instruction: audio, visual, and audio-visual presentations of the forehand tennis drive. An adaptation of the Broer-Miller tennis test was administered to 183 subjects prior to and following the training sessions. Subjects were divided into six experimental groups and one control group. Of the experimental groups, one heard, one viewed, and one both heard and viewed a sound filmstrip which described the tennis drive. Three similar experimental groups received parallel instruction but also engaged in 10-min. mental practice sessions immediately following their respective presentations. All six groups met three times a week for a period of 8 weeks. The three experimental groups which also engaged in mental practice showed a significant improvement in the execution of the forehand drive. Among the variables of instruction, audio used in conjunction with mental practice proved to be the most effective method for development of the forehand tennis stroke.     

The Effect of In-Season Traditional and Explosive Resistance Training Programs on Strength,Jump Height,and Speed in Recreational Soccer Players

Purpose: Resistance training is often performed in a traditional training style using deliberate relatively longer repetition durations or in an explosive training style using maximal intended velocities and relatively shorter repetition durations. Both improve strength, “power” (impulsivity), and speed. This study compared explosive and traditional training over a 6-week intervention in 30 healthy young adult male recreational soccer players. Method: Full body supervised resistance training was performed 2 times a week using 3 sets of each exercise at 80% of one repetition maximum to momentary failure. Outcomes were Smith machine squat 1 repetition maximum, 10 meter sprint time, and countermovement jump. Results: Both groups significantly improved all outcomes based on 95% confidence intervals not crossing zero. There were no between-group differences for squat 1 RM (TRAD = 6.3[5.1 to 7.6] kg, EXP = 5.2[3.9 to 6.4] kg) or 10 meter sprint (TRAD = ?0.05[?0.07 to ?0.04] s, EXP = ?0.05[?0.06 to ?0.03] s). Explosive group had a significantly greater increase in countermovement jump compared to the traditional group (TRAD = 0.7[0.3 to 1.1] cm, EXP = 1.3[0.9 to 1.7] cm). Conclusion: Both the traditional training and explosive training performed to momentary failure produced significant improvements in strength, speed, and jump performance. Strength gains are similar independent of intended movement speed. However, speed and jump performance changes are marginal with resistance training.     

Effect of Training Program on Total Body Reaction Time of Individuals of Low Fitness

Abstract

Twenty-six low fitness subjects were tested for total body reaction time, strength, agility, and explosive power and then retested on these items seven weeks later. During the intervening six-week period, the subjects participated in a vigorous training program consisting of four 30-minute sessions per week. Statistically significant improvements were displayed in all items tested following the training program.     

耐力运动对幼年肥胖大鼠血清瘦素水平的影响

为观察耐力运动对幼年肥胖大鼠血清瘦素的影响,将30只6周龄雄性SD肥胖大鼠随机分成肥胖对照组、45min游泳组及90min游泳组,另10只正常体重同龄SD大鼠为正常对照组。除正常对照组饲普通饲料外,其余各组均饲高脂饲料。两个运动组大鼠分别以每天1次,每次45min和90min游泳,每周6天,持续12周。实验结束后测定血TG、TC、HDL、LDL及血清瘦素。结果显示:12周耐力运动使肥胖大鼠血清TG、LDL显著降低,血清HDL显著升高;两个运动组大鼠体重增加总量明显低于两个对照组(P<0.05);肥胖对照组表现为高瘦素血症,两个运动组肥胖大鼠血清瘦素水平显著下降(P<0.01)。结果说明:耐力运动使肥胖大鼠血清TG、LDL显著降低,血清HDL显著升高;耐力运动可降低血清瘦素水平,有效地改善幼年肥胖大鼠的高瘦素血症。     

运用游泳水槽进行水感表型强化训练的实验研究

目的：为游泳运动员在水槽中进行水感表型强化训练提供参考和建议。方法：将上海市14名一级男性游泳运动员随机分为两组,A组为实验组,B组为对照组。A组每周安排3次水槽中的水感训练课,B组采用常规的泳池训练,保证两组的训练量一致,实验周期为20周。运用上海市游泳水槽系统的三线运动分析系统对运动员训练前后的技术动作进行分析与诊断,运用Tritonwear游泳运动表现分析系统对运动员训练前后50m自由泳成绩和游效指数进行分析。结果：A组与B组运动员经过一段时间的训练后,50 m自由泳成绩和游效指数都较实验前有了一定的提高;而且A组的50 m自由泳成绩和游效指数相比较B组都得到了明显的提高,实验后A组和B组队员的50 m自由泳成绩和游效指数存在显著性差异。结论：通过水槽中水感表型的多种训练方法,运动员的技术动作得到了改进,划水效果得到了提高,运动成绩也得到了提高。对水感的定量研究是我们未来的研究方向,后期还需要更加深入的研究。     

Effects of intermittent sprint and plyometric training on endurance running performance

PurposeThe purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.MethodsFourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group (n = 7) or the plyometric training group (n = 7). The preliminary tests required subjects to perform a treadmill graded exercise test, a countermovement jump test for peak power measurement, and a 10-km time trial. Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week. On completion of the intervention, post-tests were conducted.ResultsBoth groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period. There were significant improvements in the 10-km time trial performance and peak power. There was also significant improvement in relative peak power for both groups. The 10-km time trial performance and relative peak power showed a moderate inverse correlation.ConclusionThese findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage. The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.     

Developing Coincident Timing Skill in Children: A Comparison of Training Methods

Abstract

The present study attempted to determine whether the nature of training experiences influences the development of coincident timing skill in young children. The task involved visual tracking of a moving light sequence and a 43 cm arm movement to a padded target. Subjects attempted to tap the target coincident with the completion of the light sequence. Sixty first grade children were randomly assigned to one of five groups, with an equal number of males and females in each group. Subjects assigned to the training groups received 48 trials on each of two days, with stimulus speeds that were either slow (179 cm/sec or 4 mph), fast (313 cm/sec or 7 mph), varied-random (179, 224, 268, 313 cm/sec or 4, 5, 6, 7 mph), or varied-blocked (i.e., 6 consecutive trials with one speed before changing to another). Control subjects performed a neutral coloring activity during the training phase of the experiment. All subjects were then given 10 trials on a third day with each of two stimulus speeds not experienced previously; one slow (134 cm/sec or 3 mph) and one fast (358 cm/sec or 8 mph). During transfer trials all groups were more accurate with the fast than with the slow speed stimulus. Training method mattered most during slow speed transfer trials, with the most accurate performance demonstrated by the group receiving varied-blocked speeds during training. The least effective methods were fast speed training, especially for males, and varied-random speed training. It was concluded that training sessions for the development of coincident timing skill in young children should emphasize slower speed stimuli and blocking of additional speeds which are more rapid.     

运动预适应对过度训练大鼠心肌缺血缺氧损伤及血清MDA影响的研究

[目的]：研究运动预适应对过度训练大鼠心肌缺血缺氧形态影响及血清MDA.[方法]：将鼠随机分为安静对照组、一般训练组、过度训练组、运动预适应组.安静对照组常规饲氧,不加干预;一般训练组第1-2w常规饲养,第3-4w进行无负重游泳运动,每次游泳1h/d,每周游泳6天.过度训练组第1-2w常规饲养,第3-4w每天进行一次尾部负重3％体重的负荷进行力竭性游泳,每周游泳6天.运动预适应组第1-2W大鼠每天尾部负重3％体重负荷进行间歇性游泳运动一次,每天游泳15 min,休息5 min,重复3次,6 d/周,周日休息,第3-4周运动与过度训练组的第3-4周训练一致.训练结束后取材,进行常规HE染色和HBEP染色并摄片,测血清MDA.[结果]：HE染色,过度训练组肌纤维排列紊乱,部分肌纤维界限模糊.运动预适应组肌纤维轮廓较清楚.HBEP染色过度训练组有若干片状的红色缺血缺氧部位;运动预适应组心肌缺血缺氧改变程度比过度训练组明显减轻.运动各组大鼠血清MDA均高于安静对照组;过度训练组高于一般训练组和运动预适应组.[结论]：运动预适应可以降低过度训练大鼠血清MDA的含量,对心肌缺血缺氧性损伤产生保护作用.