Acute exercise-induced irisin release in healthy adults: Associations with training status and exercise mode

There is a growing interest in exploring irisin response to acute exercise; however, the associations of acute exercise-induced irisin release with training status and exercise mode are not fully understood. This study was primarily designed to evaluate these associations. Sixteen healthy adults (8 trained versus 8 untrained) underwent a bout of cycling at 80% of maximal oxygen uptake (VO_2max) for 50?min, with blood drawn pre-, 10-, and 180-min post-exercise. Another 17 healthy adults performed 2 bouts of graded exercise (cycling and running) until exhaustion on separate days using a randomized cross-over design, with blood taken pre-, 0-, 10-, and 60-min post-exercise. Circulating irisin, creatine kinase (CK), aspartate aminotransferase (AST), and myoglobin (Mb) were measured, and their respective areas under the curves (AUCs) were calculated. Irisin increased 10-min after 50?min of cycling at 80% of VO_2max, while its changes from baseline to post-exercise and the amount of exercise-induced irisin release (presented as AUC) were comparable between trained and untrained adults (all P?>?.05). Irisin remained elevated 10-min post-exhausting running but decreased towards baseline 10-min post-exhausting cycling. Exhausting running induced an increase in irisin release for the whole course of exercise and recovery periods, but cycling did not. Acute exercise-induced irisin changes seemed not related to changes of CK, aspartate AST, and Mb in general. In conclusion, acute exercise-induced irisin release is not associated with training status but might be affected by training mode. Future studies are required to investigate which exercise mode might be most efficient in altering irisin.     

一氧化氮与运动训练的研究现状与进展

采用文献资料法,介绍了NO的主要生理作用、不同形式的运动训练对NO的影响,并综述了NO与运动训练的研究现状及该领域研究中存在的问题,以及NO在运动训练中的研究意义,将来值得研究的方向。以此为运动训练提供科学依据。     

竞技体育专项训练特征及其运动训练学分析

从运动训练学角度,对专项训练多周期年度训练计划特征、专项训练的运动生理学特征、专项训练方法评价的特征进行阐释,旨在为提高运动员的专项成绩提供参考。     

Effects of plyometric training on maximal-intensity exercise and endurance in male and female soccer players

In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35–1.76), throwing (ES = 0.62–0.78), sprint (ES = 0.86–1.44), change of direction speed (ES = 0.46–0.85) and endurance performance (ES = 0.42–0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.     

Effects of movement velocity and training frequency of resistance exercise on functional performance in older adults: a randomised controlled trial

Objectives: To investigate the effects that high-velocity, low-load (HVLL) and low-velocity, high-load (LVHL) resistance exercise, performed once or twice-weekly, have on indices of functional performance (primary outcome), maximal strength, and body composition (secondary outcomes) in older adults.

Methods: In a randomised, controlled, multi-armed, parallel design, 54 moderately-highly active, but resistance exercise naïve older adults (aged 60–79 years), attended baseline and post-10-week intervention assessment sessions. Physical and functional assessments were completed, and predicted one-repetition maximums (1-RM) were obtained for eight exercises. Participants were then randomised into one of five conditions: HVLL once-weekly (HVLL1: n?=?11) or twice-weekly (HVLL2: n?=?11), LVHL once-weekly (LVHL1: n?=?10) or twice-weekly (LVHL2: n?=?11), no-exercise control condition (CON: n?=?11). The HVLL conditions completed 3 sets of 14 repetitions at 40% 1-RM and the LVHL conditions, 3 sets of 7 repetitions at 80% 1-RM. In total, 50 participants completed all testing and were included in analyses.

Results: Only LVHL2 improved 30-sec chair stand performance (p?=?.035; g?=?0.89), arm curls (p?=?.011; g?=?1.65) and grip-strength (p?=?.015; g?=?0.34) compared to CON. LVHL2 improved maximal strength compared to CON for 7/8 exercises (p?p?Conclusion: Possibly due to the lower intensity nature of the HVLL conditions, LVHL, twice-weekly was most beneficial for improving functional performance and strength in moderately-highly active older adults. Therefore, we recommend that exercise professionals ensure resistance exercise sessions have sufficient intensity of effort and volume, in order to maximise functional performance and strength gains in older adults.     

The acute effects of bodyweight suspension exercise on muscle activation and muscular fatigue

This investigation examined effects of two exercise modes (barbell, BB; bodyweight suspension, BWS) on muscle activation, resistance load, and fatigue. During session one, nine resistance-trained males completed an elbow flexion one-repetition maximum (1RM). During sessions two and three, subjects completed standing biceps curls to fatigue at 70% 1RM utilizing a randomized exercise mode. Surface electromyography (sEMG) recorded muscle activation of the biceps brachii, triceps brachii, anterior deltoid, posterior deltoid, rectus abdominis, and erector spinae. BWS resistance load was measured using a force transducer. Standing maximal voluntary isometric contractions of the elbow flexors recorded at 90° were used to determine the isometric force decrement and rate of fatigue (ROF) during exercise. sEMG and resistance load data were divided into 25% contraction duration bins throughout the concentric phase. BWS resulted in a 67.7?±?7.4% decline in resistance load throughout the concentric phase (p?≤?0.05). As a result, BB elicited higher mean resistance loads (31.4?±?4.0?kg) and biceps brachii sEMG (84.7?±?27.8% maximal voluntary isometric contractions, MVIC) compared with BWS (20.4?±?3.4?kg, 63.4?±?21.6% MVIC). No difference in rectus abdominis or erector spinae sEMG was detected between exercise modes. Isometric force decrement was greater during BWS (?21.7?±?7.0?kg) compared with BB (?14.9?±?4.7?kg); however, BB (?3.0?±?0.8?kg/set) resulted in a steeper decline in ROF compared with BWS (?1.7?±?0.6?kg/set). The variable resistance loading and greater isometric force decrement observed suggest that select BWS exercises may resemble variable resistance exercise more than previously considered.     

Inspiratory muscle training effects on oxygen saturation and performance in hypoxemic rowers: Effect of sex

ABSTRACT

Exercise-induced arterial hypoxemia (EIAH) has been consistently reported in elite endurance athletes. This study examined the effects of an inspiratory muscle training protocol (IMT) on resting pulmonary function, end-exercise arterial oxygen saturation and performance in hypoxemic rowers. Twenty male and sixteen female well-trained hypoxemic rowers were divided into four groups: IMT-male, control-male, IMT-female and control-female. The IMT groups, additionally to the regular training, performed IMT (30 min/day, 5 times/week, 6 weeks). Before and after training, groups underwent an incremental rowing test, a 2000-m time trial and a 5-min “all-out” race. IMT increased respiratory strength in the IMT-male (135 ± 31 vs. 180 ± 22 cmH₂O) and IMT-female (93 ± 19 vs. 142 ± 22 cmH₂O) (P < 0.05). The IMT-female group exhibited lower EIAH and improved rowing performance in the 2000-m time trial (487 ± 32 vs. 461 ± 34 sec) and in the 5-min “all-out” test (1,285 ± 28 vs. 1,310 ± 36m) (P < 0.05). IMT protocol improved performance in IMT-male only in the 5-min test (1,651 ± 31 vs. 1,746 ± 37m) (P < 0.05). IMT may be a useful tool for increasing respiratory strength and enhancing performance in hypoxemic rowers, especially for women.

Abbreviations: EIAH: Exercise-induced arterial hypoxemia; IMT: inspiratory muscle training protocol; PaO2: partial pressure of arterial oxygen; SaO2: arterial oxyhemoglobin saturation; VO2max: maximal oxygen consumption; [(A-a)DO2]: alveolar-to-arterial oxygen difference; VA/Q: ventilation-perfusion inequality/mismatching; PImax: maximal inspiratory pressure; BMI: body mass index; BSA: body surface area; FVC: vital capacity; FEV1: forced expiratory volume in 1 sec; VCin: vital capacity; MVV12: maximal voluntary ventilation in 12 sec     

学业可能自我与运动可能自我对运动能力的影响

为了探讨学业可能自我和运动可能自我对运动能力的影响，根据两所学校253份调查问卷对可能自我量表进行了修订，然后根据修订的可能自我量表和运动能力量表对3所学校的296名被试者进行了问卷调查，进一步验证了可能自我量表的结构效度和信度。t检验和方差分析结果表明，人口统计学变量能够影响可能自我和运动能力。分层回归分析的结果发现，在控制了人口统计学变量后，运动可能自我对运动能力有较强的预测作用，学业可能自我所解释的变异量没有显著变化。     

论运动训练系统结构及调控方法

从协同论和系统动态学角度,探讨了运动训练系统的结构,提出确定该系统目标状态的“5WIH”方法,并阐述了训练系统妁多种调控方法及其理论基础。     

不同负荷运动训练对大鼠红细胞膜ATP酶活性影响的研究

对大鼠进行1个月的运动训练发现,大、小两种不同负荷的训练可造成红细胞膜ATP酶活性的变化,进而对其整体机能产生不同的影响。力竭运动后小负荷训练组红细胞膜Na -K ATP酶活性增加,提示适宜负荷的运动训练不但可以提高安静时酶的活性,而且可增强其活性的储备力。大负荷训练组酶的活性受其膜组成及物理特性改变的影响而下降,反过来又影响膜特性与功能,提示大负荷训练造成的膜理化性质的改变是相互关联的。运动训练对Ca2 -ATP酶活性无明显影响,大负荷训练组活性的下降与其红细胞膜上脂质组成及其膜流动性的变化有关。     

The physiological effects of concurrent strength and endurance training sequence: A systematic review and meta-analysis

We conducted a systematic literature review and meta-analysis to assess the chronic effects of the sequence of concurrent strength and endurance training on selected important physiological and performance parameters, namely lower body 1 repetition maximum (1RM) and maximal aerobic capacity (VO₂max/peak). Based on predetermined eligibility criteria, chronic effect trials, comparing strength-endurance (SE) with endurance-strength (ES) training sequence in the same session were included. Data on effect sizes, sample size and SD as well other related study characteristics were extracted. The effect sizes were pooled using, Fixed or Random effect models as per level of heterogeneity between studies and a further sensitivity analyses was carried out using Inverse Variance Heterogeneity (IVHet) models to adjust for potential bias due to heterogeneity. Lower body 1RM was significantly higher when strength training preceded endurance with a pooled mean change of 3.96 kg (95%CI: 0.81 to 7.10 kg). However, the training sequence had no impact on aerobic capacity with a pooled mean difference of 0.39 ml.kg.min^?1 (95%CI: ?1.03 to 1.81 ml.kg.min^?1). Sequencing strength training prior to endurance in concurrent training appears to be beneficial for lower body strength adaptations, while the improvement of aerobic capacity is not affected by training order.     

The Effects of Exercise on Muscle Tension and Subsequent Muscle Relaxation Training

Abstract

This investigation examined the effects of physical exercise on muscle tension and subsequent muscle relaxation training. Twenty college students participated in the first phase of the study, which included a 10-minute EMG baseline, 30 minutes of pedalling on a bicycle ergometer, followed by EMG measurements on the frontalis muscle for up to 3 hours after the end of exercise. The same subjects from Phase I went on to Phase II, which included eight 32-minute EMG biofeedback training (BFT) sessions, utilizing the frontalis muscle. Ten subjects randomly assigned to the experimental group received BFT following an acute exercise bout, while the 10 subjects in the control group received no treatment. The greatest decrease in muscle tension in Phase I occurred 90 minutes after the end of the exercise. This finding was not significantly different from the baseline, indicating that there was no relaxation effect as a result of exercise. In Phase II, significant differences between pre and post-test measurements in both groups indicated that learning of relaxation did occur. However, no significant differences were found between the two groups, indicating that physical exercise did not enhance the learning of EMG BFT.     

运动训练的模糊控制模型研究

随着科学技术和现代体育的飞速发展，研究人脑在运动过程中的思维、认知和学习等心理过程，揭示运动过程中的智能活动机理是体育科学的必然发展趋势。为了探索应用模糊控制思想来模拟和研究人在运动训练过程中的模糊控制模型，首先分析指出运动训练过程实际上是一个模糊控制过程，然后以乒乓球运动的部分控制策略，建立了基于数学表达式的模糊控制模型。应用MATLAB软件绘制了直观模型立体图，指出了模型优化方法，并对该建模方法作了详细讨论。在此基础上提出了该理论的应用方案。     

力量训练、有氧运动对体能类男性运动员BMI、骨骼肌含量、体脂百分比的影响

选取20名体能类男性运动员,分为力量训练组和有氧训练组进行为期8周的对照实验。实验发现不同运动对人体成分的改变效果不同,力量训练可以促进骨骼肌的增长,有氧训练可以起到降低体重、减小体脂、抑制骨骼肌增长的作用。     

The effects of imagery training on fast isometric knee extensor torque development

Abstract

We hypothesized that imagery training would improve the fast onset of neuromuscular activation and thereby fast knee extensor isometric torque development. Forty young healthy participants, not involved in strength training, were assigned to one of four groups: physical training, imagery training, placebo training or control. The three training groups had three 15 min sessions per week for 4 weeks, with a 90° knee angle but were tested also at 120°. At 90° knee angle, maximal torque increased (～8%) similarly in all three training groups. The torque–time integral (contractile impulse) over the first 40 ms after torque onset (TTI40) increased (P < 0.05) after physical training (by ～100%), but only at 90°. This increase was significantly different from the delta values (change pre to post) in the control and placebo groups, whereas delta values in the imagery group were similar to those in the placebo group. The increases in TTI40 following physical training were related (r ² = 0.81, P < 0.05) to significant increases of knee extensor rectified surface EMG at torque onset (EMG40). In conclusion, only physical training led to a knee angle specific increase of contractile impulse that was significantly different from placebo and controls and that was related to improved onset of neuromuscular activation.     

不同运动量训练对大鼠血睾酮及相关指标的影响

为探讨运动量与血睾酮及相关指标的关系，对大鼠进行小运动量和大运动量两种训练，观察不同运动量对大鼠血清总睾酮(TT)、游离睾酮(FT)和皮质酮(C)浓度的影响。结果显示：小运动量组大鼠血清TT、FT和C均未出现明显下降；大运动量组大鼠血清TT、FT和C均出现显著性降低，并且TT／C值下降幅度达40．22％。因此认为，过度训练引起运动性低血睾酮，适度的运动量训练可以避免低血睾酮；血清游离睾酮的极度低下是引起低血睾酮的直接因素；血清皮质酮浓度降低反映机体应激能力低下；TT／C值可作为判断过度训练的参考指标。     

The effects of resistance training volume on osteosarcopenic obesity in older women

The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0 ± 4.3 years, 26.8 ± 4.4 kg/m²) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n = 21) or 3 sets (G3S, n = 20) 3 times weekly, or a control group (CG, n = 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (P < 0.05) positive changes for G3S than G1S (composed Z-score: G3S = 0.62 ± 0.40; G1S = 0.11 ± 0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.     

不同负荷的运动训练对大鼠心血管系统调节肽分泌的影响

为了研究不同负荷的运动训练对机体心血管系统神经调节肽分泌的影响 ,本文通过对大鼠进行为期 8周的不同负荷的游泳训练 ,并测定血浆神经肽Y(NPY)和降钙素基因相关肽 (CGRP)的含量。结果发现 :① 1h的运动训练可使血浆NPY含量显著下降 ,NPY/CGRP有下降趋势。降低机体交感神经的兴奋性 ,抑制NPY的分泌。② 2h训练组血浆NPY含量显著高于对照组和 1h训练组 ,血浆CGRP含量显著低于对照组 ,NPY/CGRP显著高于对照组和 1h训练组。动态观察血浆NPY和CGRP的含量对于在运动过程中对心血管系统进行医务监督、预防过度训练的发生具有一定的指导意义     

Systematic review of the acute and chronic effects of high-intensity interval training on executive function across the lifespan

ABSTRACT

Research regarding the effects of high-intensity interval training (HIIT) on executive function has grown exponentially in recent years. However, there has been no comprehensive review of the current state of literature. Therefore, the aim of this systematic review is to summarize previous research regarding the acute and chronic effects of HIIT on executive function across the lifespan and highlight future research directions. The results indicated that acute bouts of HIIT has a positive effect on inhibition in children/adolescents and adults, and further that chronic HIIT benefits inhibition and working memory in children. More research employing chronic interventions, focusing on middle-aged and older adults, and examining the effects on the working memory and cognitive flexibility domains of executive function are needed. Future research should also focus on a) the use of stronger research designs, b) the effects of HIIT dosage/modality, c) consideration of individual differences, d) possible underlying mechanisms, and e) examining the feasibility of translating HIIT to real-word settings.