Single versus Multiple Sets for Strength: A Meta-Analysis to Address the Controversy

We assessed the factor structure of a revised version of the Exercise Imagery Inventory (EII; Giacobbi, Hausenblas, &; Penfield, 2005), second-order interrelationships for cognitive and motivational forms of mental imagery, and associations with exercise behavior and barriers self-efficacy. A convenience sample of 358 (M age = 20.55 years, SD = 3.88) college students completed the EII-revised (EII-R), a measure of barriers self-efficacy and the Leisure-Time Exercise Questionnaire. The EII-R demonstrated reliability and factorial validity with good model fit statistics. We observed second-order relationships among scale scores and discriminant validity evidence that distinguished cognitive (e.g., exercise technique, exercise routines) and motivational (e.g., appearance/health, exercise self-efficacy, exercise feelings) factors. The second-order imagery factors were significantly and moderately associated with barriers self-efficacy and exercise behavior.     

The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis

The purpose of this systematic review and meta-analysis is to assess the effect of concurrent high intensity interval training (HIIT) and resistance training (RT) on strength and hypertrophy. Five electronic databases were searched using terms related to HIIT, RT, and concurrent training. Effect size (ES), calculated as standardised differences in the means, were used to examine the effect of concurrent HIIT and RT compared to RT alone on muscle strength and hypertrophy. Sub-analyses were performed to assess region-specific strength and hypertrophy, HIIT modality (cycling versus running), and inter-modal rest responses. Compared to RT alone, concurrent HIIT and RT led to similar changes in muscle hypertrophy and upper body strength. Concurrent HIIT and RT resulted in a lower increase in lower body strength compared to RT alone (ES = ?0.248, p = 0.049). Sub analyses showed a trend for lower body strength to be negatively affected by cycling HIIT (ES = ?0.377, p = 0.074) and not running (ES = ?0.176, p = 0.261). Data suggests concurrent HIIT and RT does not negatively impact hypertrophy or upper body strength, and that any possible negative effect on lower body strength may be ameliorated by incorporating running based HIIT and longer inter-modal rest periods.     

阻力训练及超等长阻力训练对下肢肌肉活性和力量的影响

目的:观察阻力训练和超等长阻力训练后下肢肌肉力量变化,比较肌肉激活模式的不同.方法:将16名男性篮球运动员随机分成两组,分别实施8周下肢阻力训练和超等长阻力训练.采用3-D测力台测试训练前、后最大随意收缩值,用表面肌电记录训练前、后6次重复训练动作的胫骨前肌、腓肠肌外侧头、股直肌、股外侧肌、股二头肌的激活信号,计算积分肌电值和髋、膝、踝关节周围拮抗肌共激活.结果:两组下肢肌肉力量均显著提高,阻力训练组效果较明显.超等长阻力训练组肌肉活性显著高于阻力训练组.训练后超等长阻力训练组肌肉活性出现适应性变化,髋、踝关节拮抗肌共激活显著升高,膝关节拮抗肌共激活训练前、后没有显著性差异.阻力训练组训练前、后肌肉活性及拮抗肌共激活没有显著变化.结论:超等长阻力训练有助于提高肌肉间协调性,可以优化肌肉动作的运动策略.     

创新型体育人才的培养模式

民族创新首先需要创新人才和创新的教育.体育高等教育肩负培养创新型体育高级人才之重任,创新型人才的成长需要创新的教育和环境.     

抗阻力训练的减肥效果

运用文献检索查阅与分析的方法,从抗阻力训练对人体能量消耗、静息代谢率、以及抗阻力训练与其他干预手段相结合等方面,分析阐述了抗阻力训练对人体减肥效果的影响,旨在阐明目前国外对该问题的研究现状与动态。结果:多数研究认为抗阻力训练可以提高去脂体重,增加静息代谢率,具有较好的减肥效果。也有研究认为抗阻力训练不具有减肥效果。尽管单纯抗阻力训练的减肥效果目前还没有形成统一认识,但抗阻力训练与其他手段相结合则是有效的减肥手段。     

The Effect of Whole-Body Vibration on Lower-Body Resistance Detraining in College-Age Women

Purpose: This study explored the effect of whole-body vibration (WBV) using accelerations of 2.56 g to 7.68 g on lower-body detraining. Methods: All participants (N = 20) were trained using a lower-body resistance-training program for 30 min twice per week from Week 0 to Week 6. At the end of the program, they were randomly assigned to a control group that performed no further training or a WBV group that performed a progressive static WBV program. Data for the 5-repetition-maximum (5RM) squat and extensors and flexors of the knee and ankle were collected at Weeks 0, 6, 8, 10, and 12 for all participants. Results: Two-way (condition vs. time) analysis of variance revealed that although the WBV group maintained strength in the 5RM from Week 6 through Week 8 and the control group had a lower 5RM in Week 8 from Week 6, no differences in the 5RM squat existed between the groups at Week 8. Two-way factorial multivariate analysis of variance revealed no differences between the groups at any of the time for torque of knee flexion, dorsiflexion, or plantar flexion. Conclusion: Static WBV of 2.56 g to 7.68 g did not attenuate detraining of the flexors and extensors of the knee and ankle.     

Influence of physiological characteristics on selection in a semi-professional first grade rugby league team: a case study

The aim of this study was to determine whether the physiological characteristics of players influence selection in a semi-professional first grade rugby league team. Sixty-six semi-professional rugby league players aged 24 - 4 years (mean - s ) were monitored over two competitive seasons. The players underwent measurements of body mass, muscular power (vertical jump), speed (10, 20, 30 and 40 m sprint), agility (Illinois agility run) and estimated maximal aerobic power (multi-stage fitness test) 1 week before their first competition match. After selection for either the first or second grade team, the results of all physiological tests were collated and analysed to determine if there were any physiological differences between players selected for the two teams. Players selected to play in the first grade team were significantly ( P ? 0.05) older (25 - 4 vs 22 - 4 years) and heavier (93 - 10 vs 86 - 10 kg) and had more playing experience (18 - 6 vs 15 - 6 years) than second grade players. Muscular power, speed, agility and estimated maximal aerobic power were not significantly different ( P > 0.05) between first grade and second grade players. These results suggest that the physiological capacities of players do not influence selection in a semi-professional first grade rugby league team. Rather, player selection appears to be based on body mass, playing experience and skill. These results support the need for a standardized skills performance test for semi-professional rugby league players.     

跆拳道运动抗击打能力训练方法的实验研究

为了提高高校体院跆拳道专业学生身体抗打击能力,减少不必要的损伤,提高运动成绩,树立自信心,针对以往高校体院跆拳道专业学生,只注重学习动作发展力量及灵敏素质等,而提出在上课中加重身体抗打击训练比重。试论是否可以有利于教学,促进学生学习的积极性和自信心。     

大负荷力量训练对举重运动员有氧能力的影响

目的:探讨大负荷力量训练对举重运动员造血机能、最大耗氧量及运动后血乳酸动力学的影响。方法:选25名优秀男子举重运动员,完成为期5周“二大一调整”式力量训练,其中,第1、2周为大负荷周,第3周为调整周,第4、5周为大负荷周,第4周冲击最大负荷。大负荷周为目标总重量30000kg/d,每天2次训练课,调整负荷为目标总重量小于15000kg/天,每天1次训练课,每周训练6天。于训练前、训练第1、2、3、4、5周取周训练结束后次日晨基础状态静脉血测定红系指标,于试验前、后测定最大耗氧量(V.O2max)及.VO2max测试结束后0、5、10、15min血乳酸变化趋势。结果:训练期间红细胞(RBC)、红细胞压积(Hct)、血红蛋白(Hgb)、血小板(Plt)、血小板压积(Pct)均较试验前显著性下降,但在第5周红细胞、血红蛋白均出现回复性变化;平均红细胞体积(MCV)减小,而平均红细胞血红蛋白(MCH)、红细胞体积分布宽度(RDW)、血小板体积分布宽度(PDW)均呈增加趋势;调整周内血红蛋白不仅没有回复,反而呈显著性下降。训练期间外周血网织红细胞(Ret)先增加后回复。5周训练后,V.O2max较训练前显著提高,.VO2max测试后0、5、10、15min血乳酸低于训练前对应点。结论:一定量的大负荷力量训练提高运动员红系造血活动及V.O2max;一定量大负荷力量训练改变定量负荷后血乳酸代谢的动力学特征,其可能的机制是机体清除乳酸的能力提高。     

Effect of carrying different military equipment during a fatigue test on shooting performance

This study investigated the effect of a 3-km walking test (3kWT) carrying different military equipment on shooting performance, rating of perceived exertion (RPE), heart rate (HR), and test time. The relative combat wear and backpack weight (as percentage of soldier’s body weight [%BW]) was reported and, along with HR, its relationship to marksmanship variables was tested. Thirty-nine Spanish Army males walked as fast as possible to complete the 3kWT in the following conditions in a randomized order: unloaded walking; wearing the combat uniform; and carrying the combat uniform plus combat backpack. A shooting test was completed before and after the 3kWT. The HR and RPE were evaluated. The marksmanship variables and HR were analysed using a two-way repeated measures ANOVA, and a repeated ANOVA was also used for 3kWT completion time and HR reserve analysis. Correlation analyses were performed between the equipment’s weight, HR, and marksmanship variables. The results showed that shooting score decreased after the 3kWT in both load conditions (p?r?=??0.35; p?=?0.04) and cleanness triggering (r?=?0.37; p?=?0.03). Correlations between HR and shooting variables were non-significant. In conclusion, wearing the Spanish Army combat wear and backpack resulted in shooting performance degradation. Furthermore, fatigue and RPE increased and this could decrease physical marksmanship and performance capacity in combat situations.     

一般耐力性训练对初中生发育的影响

通过对 44 1名初中学生三年追踪研究发现 :在每周原来体育锻炼的基础上 ,增加 4次 2 0min以上的一般耐力性训练 ,能够促进该时期青少年身体正常高速生长与各组织器官的同步发育 ,同时学习成绩也得到提高。研究表明 :一般耐力性训练能够促进初中生身心全面健康发展。     

Injury prevention in camogie: Current trends in the use of protective equipment

Abstract

Camogie is one of Ireland's national field sports. The aim of this study was to investigate the use of protective equipment by camogie players and to identify the most common injuries resulting from playing camogie. A questionnaire was distributed to 180 camogie players at randomly chosen clubs in two Irish counties to establish use of protective equipment over the preceding 12 months and what injuries resulted from playing camogie over the same period. Direct observation of players in action was undertaken looking at protective equipment use to confirm reliability of the self-reported data. One hundred and thirty-nine questionnaires were returned and 120 players directly observed. In total, 74.8% of players reported wearing a helmet every time and 84.9% that they never wear a handguard. Reasons for not wearing protective equipment include discomfort and the belief that it is unnecessary. Thirty-seven percent of players reported injury; hand injuries were the most common (42.3% of all injuries). One in six players experienced a hand injury over the 12-month period. Generating awareness of the prevalence of hand injuries and the lack of hand protection in camogie is required.     

不同负荷杠铃阻力训练过程中人体功率输出特征研究

目的探讨在不同负荷的杠铃阻力练习过程中负荷强度与功率输出的相互关系。方法 12名男性受试着,在Kistler三维测力台上分别负30%1RM、70%1RM、90%1RM杠铃完成快速蹲起动作,高速摄影同步监测。结果随着负荷的变化,蹬地力值、荷重、做功之间都有显著不同(P<0.01),蹬地力量逐渐增加;重心加速度和速度逐渐减小;但不同负荷间功率输出均保持在一个较高水平,组间无显著性差异(P>0.05)。结论 结果显示,3种不同强度的阻力训练对提高人体功率输出的作用基本一致,并不像通常认为的不同负荷强度发展不同力量能力。提示应从新的角度审视杠铃阻力训练中负荷强度与功率发展的关系。     

Validity of Activity Trackers in Estimating Energy Expenditure During High-Intensity Functional Training

ABSTRACT

Purpose: The purpose of this study was to evaluate the agreement of five commercially available accelerometers in estimating energy expenditure while performing an acute bout of high-intensity functional training (HIFT). Methods: Participants (n = 47; average age: 28.5 ± 11.6 years) consisted of recreationally active, healthy adults. Each participant completed a session of HIFT: a 15-minute workout consisting of 12 repetitions each of air-squats, sit-ups, push-ups, lunges, pull-ups, steps-ups, and high-knees; performed circuit-style by completing as many rounds as possible. During this session, each participant wore the Cosmed K4b2 portable metabolic analyzer (PMA) and five different accelerometers (ActiGraph GT3X, Nike Fuelband, Fitbit One, Fitbit Charge HR, and Jawbone UP Move). Results: Four of the five activity trackers reported lower (p < .05) total EE values compared to the PMA during the acute bout of HIFT. The waist-mounted device (ActiGraph, 182.55 ± 37.93 kcal) was not significantly different from, and most closely estimated caloric expenditure compared to the PMA (144.99 ± 37.13 kcal) (p = .056). A repeated-measures ANOVA showed that all activity trackers were significantly different from the reference measure (PMA) (p < .05). Systematic relative agreement between the activity trackers was calculated, exhibiting a significant ICC = 0.426 (F [46,230] = 5.446 [p < .05]). Conclusion: The wrist- and hip-mounted activity trackers did not accurately assess energy expenditure during HIFT exercise. With the exception of the ActiGraph GT3X, the remaining four activity trackers showed inaccurate estimates of the amount of kilocalories expended during the HIFT exercise bout compared to the PMA.     

Three dimensional musculoskeletal modelling of the seated biceps curl resistance training exercise

The aim of this study was to evaluate the benefits and limitations of using three dimensional (3D) musculoskeletal modelling (LifeModeler?) in assessing the safety and efficacy of exercising on a seated biceps curl resistance training machine. Three anthropometric cases were studied, representing a 5^th percentile female, 50^th percentile and 95^th percentile male. Results indicated that the LifeModeler? default model was not adequate to solve the forward dynamics simulations. Therefore adjustments had to be made to the default model to successfully complete the forward dynamics simulations. The software was able to sufficiently highlight the shortcomings of the biceps curl machine's engineered adjustability in relation to the anthropometric dimensions of the studied cases, as the 5^th percentile female could not be accommodated suitably on the machine. High lumbar spine anterior/posterior shear forces for all anthropometric cases and maximum muscle tensions for the female and 50^th percentile male indicate that the seated biceps curl exercise may pose risks for injuries. To conclude, it appears that 3D musculoskeletal modelling can be used to evaluate resistance training equipment such as the seated biceps curl machine. However the limitations as indicated by this study must be taken into consideration, especially when using the default LifeModeler? model.     

Strength training: Isometric training at a range of joint angles versus dynamic training

Strength training with isometric contractions produces large but highly angle-specific adaptations. To contrast the contractile mode of isometric versus dynamic training, but diminish the strong angle specificity effect, we compared the strength gains produced by isometric training at four joint angles with conventional dynamic training. Thirty-three recreationally active healthy males aged 18?–?30 years completed 9 weeks of strength training of the quadriceps muscle group three times per week. An intra-individual design was adopted: one leg performed purely isometric training at each of four joint angles (isometrically trained leg); the other leg performed conventional dynamic training, lifting and lowering (dynamically trained leg). Both legs trained at similar relative loads for the same duration. The quadriceps strength of each leg was measured isometrically (at four angles) and isokinetically (at three velocities) pre and post training. After 9 weeks of training, the increase in isokinetic strength was similar in both legs (pooled data from three velocities: dynamically trained leg, 10.7%; isometrically trained leg, 10.5%). Isometric strength increases were significantly greater for the isometrically trained leg (pooled data from four angles: dynamically trained leg, 13.1%; isometrically trained leg, 18.0%). This may have been due to the greater absolute torque involved with isometric training or a residual angle specificity effect despite the isometric training being divided over four angles.     

Acute adaptations and subsequent preservation of strength and speed measures following a Nordic hamstring curl intervention: a randomised controlled trial

This randomised controlled trial investigated changes in eccentric hamstring strength, 10m sprint speed, and change-of-direction (COD) performance immediately post Nordic hamstring curl (NHC) intervention and following a 3-week detraining period.

Fourteen male team sports athletes were randomised to a do-as-usual control group (CG; n = 7) or to a NHC intervention group (NHC; n = 7). Isokinetic dynamometry at 180°/s evaluated eccentric hamstring strength immediately post-intervention as the primary outcome measure. Secondary outcomes included 10 m sprint time and COD. Each outcome was measured, pre, immediately post-intervention and following a 3-week detraining period.

Immediately post-intervention significant group differences were observed in the NHC group for eccentric hamstring strength (31.81 Nm^?1 vs. 6.44 Nm^?1, P = 0.001), COD (?0.12 s vs. 0.20 s; P = 0.003) and sprint (- 0.06 s vs. 0.05 s; P = 0.024) performance. Performance improvements were maintained following a detraining period for COD (?0.11 s vs. 0.20 s; P = 0.014) and sprint (?0.05 s vs. 0.03 s, P = 0.031) but not eccentric hamstring strength (15.67 Nm^?1 vs. 6.44 Nm^?1, P = 0.145) These findings have important implications for training programmes designed to reduce hamstring injury incidence, whilst enhancing physical qualities critical to sport.     

羽毛球专项抗阻训练计划的设计与分析

利用文献资料、录像分析等方法,设计旨在提升羽毛球运动员专项运动表现的抗阻训练计划,分析如何将这些练习适时地运用于准备期及竞赛期的训练组织过程当中。     

可变阻力训练对爆发力影响的系统综述

研究目的:探究铁链、弹力带与恒定阻力结合的可变阻力训练方式对爆发力的影响。研究方法:检索铁链、弹力带与恒定阻力结合的可变阻力训练相关研究文献,将最大力量、动作速度和功率输出3个指标与恒定阻力训练相关数据进行对比。结果:较多的研究显示,铁链、弹力带与恒定阻力结合的可变阻力训练方式相对于传统的恒定阻力训练,在最大力量、动作速度和功率输出方面让训练者获得更大的效益。也有部分实验显示,可变阻力训练虽然取得了效果,但未见明显的优势。结论:铁链、弹力带与恒定阻力结合的可变阻力训练对爆发力影响总体是正向的,但内在机制尚不明确。     

The time-frame of acute resistance exercise effects on football skill performance: The impact of exercise intensity

Abstract

The purpose of this study was to determine the recovery rate of football skill performance following resistance exercise of moderate or high intensity. Ten elite football players participated in three different trials: control, low-intensity resistance exercise (4 sets, 8–10 repetitions/set, 65–70% 1 repetition maximum [1RM]) and high-intensity resistance exercise (4 sets, 4–6 repetitions/set, 85–90% 1RM) in a counterbalanced manner. In each experimental condition, participants were evaluated pre, post, and at 24, 48, 72 h post exercise time points. Football skill performance was assessed through the Loughborough Soccer Passing Test, long passing, dribbling, shooting and heading. Delayed onset muscle soreness, knee joint range of motion, and muscle strength (1RM) in squat were considered as muscle damage markers. Blood samples analysed for creatine kinase activity, C-reactive protein, and leukocyte count. Passing and shooting performance declined (P < 0.05) post-exercise following resistance exercise. Strength declined post-exercise following high-intensity resistance exercise. Both trials induced only a mild muscle damage and inflammatory response in an intensity-dependent manner. These results indicate that football skill performance is minimally affected by acute resistance exercise independent of intensity suggesting that elite players may be able to participate in a football practice or match after only 24 h following a strength training session.