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1.
The purpose was to examine changes in the perceptual responses to lifting a very low load (15% one repetition maximum (1RM)) with and without (15/0) different pressures [40% (15/40) and 80% (15/80) arterial occlusion pressure] and compare that to traditional high load (70/0) resistance exercise. Ratings of perceived exertion (RPE) and discomfort were measured following each set of exercise. In addition, resting arterial occlusion pressure was measured prior to exercise. Assessments were made in training sessions 1, 9, and 16 for the upper and lower body. Data are presented as means and 95% CI. There were changes in RPE in the upper body with condition 15/40 [?2.1 (?3.4, ?0.850)] and 15/80 [?2.4 (?3.6, ?1.1)] decreasing by the end of training. In the lower body, RPE decreased in condition 15/40 [?1.4 (?2.3, ?0.431)] by the end of the training study. There was a main effect of time in the upper body with all conditions decreasing discomfort. In the lower body, all conditions decreased except for 15/80. For arterial occlusion pressure, there were differences across time in the 15/40 condition and the 15/80 condition in the upper body. Repeated exposure to blood flow restriction may dampen the perceptual responses over time.  相似文献   

2.
ABSTRACT

Purpose: The purpose of this study was to identify whether post-resistance exercise (REx) blood flow restriction (BFR) can elicit a similar acute training stimulus to that offered by either heavy REx or traditional low-load BFR REx. Method: Ten men completed trials with 30% one-repetition maximum (1RM) for 5 sets of 15 repetitions without BFR (30%), with BFR during exercise (30% RD), and with postexercise BFR (30% RP) and at 75% 1RM for 3 sets of 10 repetitions. Lactate and cortisol were measured before and up to 60 min after exercise. Thigh circumference, ratings of perceived exertion (RPE), and pain were measured before and after exercise. Surface electromyography was measured during exercise. Results: All conditions had a large effect (effect size [ES] > 0.8) on lactate, with the largest effects observed with the 75% condition; no differences were observed between the 30% conditions. All conditions had a moderate effect (ES > 0.25 ≤ 0.4) on increasing thigh circumference. This effect was maintained (ES = 0.35) with the application of BFR after REx (30% RP). Change in RPE, from the first to last set, was significantly greater with 30% RD compared with other conditions (all p < .05). Electromyography amplitude was higher and percentage change was greater for the 75% condition compared with the other conditions (both p < .05). Conclusions: The application of BFR immediately post-REx altered several of the responses associated with REx that is aimed at inducing muscular hypertrophy. Additionally, these changes occurred with less pain and perceived exertion suggesting that this form of REx may offer an alternative, tolerable method of REx.  相似文献   

3.
To investigate the effects of a single high-load (80% of one repetition maximum [1RM]) set with additional drop sets descending to a low-load (30% 1RM) without recovery intervals on muscle strength, endurance, and size in untrained young men. Nine untrained young men performed dumbbell curls to concentric failure 2–3 days per week for 8 weeks. Each arm was randomly assigned to one of the following three conditions: 3 sets of high-load (HL, 80% 1RM) resistance exercise, 3 sets of low-load [LL, 30% 1RM] resistance exercise, and a single high-load (SDS) set with additional drop sets descending to a low-load. The mean training time per session, including recovery intervals, was lowest in the SDS condition. Elbow flexor muscle cross-sectional area (CSA) increased similarly in all three conditions. Maximum isometric and 1RM strength of the elbow flexors increased from pre to post only in the HL and SDS conditions. Muscular endurance measured by maximum repetitions at 30% 1RM increased only in the LL and SDS conditions. A SDS resistance training program can simultaneously increase muscle CSA, strength, and endurance in untrained young men, even with lower training time compared to typical resistance exercise protocols using only high- or low-loads.  相似文献   

4.
The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean?±?SD: age?=?26?±?6 years, stature?=?182?±?9?cm, body mass?=?84?±?9?kg, resistance training experience?=?7?±?3 years) consumed placebo or 6?mg?kg?1 of anhydrous caffeine 1?h before testing. Muscular power was assessed with seated medicine ball throw and vertical jump exercises, muscular strength with one-repetition maximum (1RM) barbell back squat and bench press exercises, and muscular endurance with repetitions of back squat and bench press exercises (load corresponding to 60% of 1RM) to momentary muscular failure. RPE and PP were assessed immediately after the completion of the back squat and bench press exercises. Compared to placebo, caffeine intake enhanced 1RM back squat performance (+2.8%; effect size [ES]?=?0.19; p?=?.016), which was accompanied by a reduced RPE (+7%; ES?=?0.53; p?=?.037), and seated medicine ball throw performance (+4.3%, ES?=?0.32; p?=?.009). Improvements in 1RM bench press were not noted although there were significant (p?=?.029) decreases in PP related to this exercise when participants ingested caffeine. The results point to an acute benefit of caffeine intake in enhancing lower-body strength, likely due to a decrease in RPE; upper-, but not lower-body power; and no effects on muscular endurance, in resistance-trained men. Individuals competing in events in which strength and power are important performance-related factors may consider taking 6?mg?kg?1 of caffeine pre-training/competition for performance enhancement.  相似文献   

5.
目的:探讨急性离心运动伴4种不同程度的血流限制对年轻女性外周疲劳及心脏自主神经功能的影响,综合评价各方案的安全性,为长期血流限制运动干预提供参考。方法:将40名女大学生随机分为4组,分别进行小强度抗阻(30%1RM)伴0%(CON组)、40%(BFR40组)、60%(BFR60组)和80%(BFR80组)动脉闭塞压(AOP)的血流限制运动。各小组进行4组伸膝离心运动,第1组重复30次,后3组重复15次,组间休息30 s。检测运动前、运动后即刻、15 min、30 min、1 h以及24 h的骨骼肌收缩性能(最大径向位移、收缩速度)、最大等长力量和心脏自主神经功能。结果:1)与CON组相比,BFR40组的副交感神经活性受到轻微抑制(P<0.05),可在运动后30 min内恢复(P>0.05);2)BFR60组的最大等长力量在运动后显著下降(P<0.01),副交感神经活性进一步抑制(P<0.01),交感神经支配增强(P<0.05),运动后30 min内恢复交感—副交感神经的平衡性(P>0.05);3)BFR80组运动后诱发显著的外周疲劳(P<0.01),使副交感恢复显著延迟,交感活性大幅增强(P<0.05),需更长时间恢复交感—副交感神经的平衡性(24 h内);4)相关性分析显示,副交感神经活性分别与最大径向位移(r=0.65)、收缩速度(r=0.62)和最大等长力量(r=0.55)呈正相关(P<0.05),交感神经活性与上述3个指标呈负相关(P<0.05)。结论:血流限制运动中,40%AOP会抑制迷走神经活性;60%AOP可明显影响交感神经活性和交感—副交感调控的平衡性;80%AOP可诱发显著的外周疲劳,且与心脏自主神经调控密切相关。综上所述,不建议心血管风险高的患者使用80%AOP训练。  相似文献   

6.
Abstract

During prolonged exercise, ratings of perceived exertion (RPE) and affect (pleasure; activation) play an important role in performance, especially in hot conditions. Although various mechanisms have been tried to manage the effects of heat (e.g. cooling jackets), the purpose of the current research was to assess the effect of a cooling collar on RPE, affect, thermal sensation, and running performance in the heat. Participants (n =8) wore a cold collar, uncooled collar or no collar as they completed three 90-min preloaded treadmill time-trials in the heat (30.5±0.1°C), which included 75 min at ～60% [Vdot]O2max followed by a 15-min time-trial. Affect, RPE, and thermal sensation were measured throughout. Performance during the time-trial was significantly improved in the cold collar compared with the uncooled collar and no-collar trials; however, pleasure and activation ratings were highest for the no-collar trial. Findings suggest that a cooling collar may improve performance, but not necessarily “feel good”. Practically, it seems necessary to ensure sufficient education about the benefits, on balance, of the cold collar, while the performance improvements outweighed the reported discomfort of athletes in this study. In addition, the cold collar may prove quite beneficial for individuals who work in hot climates and or conditions, as it may be effective in minimizing discomfort associated with heat for other groups as well.  相似文献   

7.
The literature related to Borg's ratings of perceived exertion (RPE) scale has revealed inconsistencies about the strength of the relationship between ratings of perceived exertion and various physiological criterion measures, such as heart rate, blood lactate concentration, percent maximal oxygen uptake (%VO2max), oxygen uptake (VO2), ventilation and respiration rate. Using sex of participants, fitness, type of RPE scale used, type of exercise, exercise protocol, RPE mode and study quality, we undertook a meta-analysis to determine the strength of the relationship between RPE scores and the six aforementioned physiological measures. The weighted mean validity coefficients were 0.62 for heart rate, 0.57 for blood lactate, 0.64 for %VO2max 0.63 for VO2, 0.61 for ventilation and 0.72 for respiration rate. Analysis of moderator variables revealed that the following study features could account for the variation of results across studies: heart rate--fitness, type of exercise, protocol and RPE mode; blood lactate concentration--sex, RPE scale; VO2--sex, exercise type, RPE mode; ventilation--sex, RPE mode; respiration rate--exercise protocol, RPE mode. The highest correlations between ratings of perceived exertion and the various physiological criterion measures were found in the following conditions: when male participants (whose VO2 or ventilation was measured) were required to maximally exert themselves (measuring %VO2max or ventilation); when the exercise task was unusual [e.g. when participants were swimming, which is less common than walking or running (when heart rate, %VO2max and VO2 are measured)]; or when the 15-point RPE scale (measuring blood lactate concentration) was used. These findings suggest that although Borg's RPE scale has been shown to be a valid measure of exercise intensity, its validity may not be as high as previously thought (r = 0.80-0.90), except under certain conditions.  相似文献   

8.
目的:为了探讨血流限制训练的历史脉络、研究现状以及存在的争议。方法:通过文献资料、逻辑分析、归纳总结等研究方法梳理血流限制训练的历史脉络,进一步分析、验证其对人体健康体适能的效果以及对其存在的争议进行剖析归因。结果与结论:血流限制训练可成为传统高强度力量训练的可行替代方式,对不同人群的健康都具有积极促进作用;负荷强度≤40%1RM的血流限制训练对肌肉适能具有正向效益,在特定条件下可提高肌肉的最大力量及横截面积;血流限制训练可通过增加机体VO2max、改善血管内皮功能和外周血循环、提高心脏代谢能力达到促进心肺耐力的目的;此外,血流限制训练结合小负荷运动能够有效改善人体身体成分、显著降低体脂肪量增加幅度。提示:加压压力取值与训练的安全性是紧密相连的,对不同人群的合理加压压力取值是需要进一步监控和评估的。  相似文献   

9.
ABSTRACT

This study aimed to analyze the acute effect of inter-repetition rest (IRR) intervals on mechanical and metabolic response during four resistance exercise protocols (REPs). Thirty resistance-trained men were randomly assigned to: continuous repetitions (CR), 10 s (IRR10) or 20 s (IRR20) inter-repetition rest. The REPs consisted of 3 sets of 6, 5, 4 and 3 repetitions against 60, 70, 75 and 80% 1RM, respectively, in the full squat exercise. Muscle fatigue was assessed using: percentage of velocity loss over three sets, percentage of velocity loss against the ~1 m·s?1 load (V1 m·s?1), and loss of countermovement jump (CMJ) height pre-post exercise. Blood lactate was measured before and after exercise. The percentage of velocity loss over three sets and lactate concentration were significantly lower (P < 0.05) for IRR groups compared to CR in all REPs. The CR group showed a significantly higher (P < 0.05) velocity loss against V1 m·s?1 load and loss of CMJ height pre-post exercise than IRR groups in REP against 60% 1RM. In conclusion, both IRR groups produced a significant lower degree of fatigue compared to CR group. However, no significant differences were found in any measured variables between IRR configurations.  相似文献   

10.
目的近些年来,加压训练因其显著的增肌效果而受到关注。但是,不同程度的血流限制对生长激素、睾酮等与增肌效果密切相关的合成类激素的影响目前还没有明确的研究结果。为此,观察了普通人在4种不同血流限制压力条件下,训练前后血清生长激素、睾酮等激素的变化,为今后进行加压训练时选择适宜压力提供实验依据。方法以10名健康成年男性为实验对象,在不同日期的同一时间点,分别在上肢0 mmHg、下肢0 mmHg(对照组),上肢100 mmHg、下肢140 mmHg(低压组),上肢140 mmHg、下肢180 mmHg(中压组),上肢180 mmHg、下肢220 mmHg(高压组)4种压力条件下,进行4组30%1RM的深蹲、屈臂、伸臂运动。每组均要求尽力完成30次(如完不成则做到力竭为止)。在运动前后测量上肢围度,并取肘静脉血测量生长激素和睾酮。而在运动后第2 min测指血血乳酸浓度,并记录主观疲劳度。结果1)3个加压组完成的总负荷均显著低于对照组(P<0.05),高压组显著低于低压组和中压组(P<0.05),而后二者之间无显著差异。2)各组间运动后血乳酸无显著差异,但3个加压组上肢放松围变化幅度和主观疲劳度均显著高于对照组(P<0.001)。其中,高压组的放松围变化显著低于低压组和中压组,高压组的主观疲劳度显著高于低压组和中压组P<0.05),而后二者之间无显著差异。3)运动后,4组的生长激素均显著增加(P<0.001)。其中,3个加压组的变化幅度显著大于对照组(P<0.05),低压组和中压组显著高于高压组(P<0.05),而低压组和中压组之间无显著性差异。4)对照组(的血睾酮)在运动前后无显著变化,而3个加压组均显著上升(P<0.05),但相互间均无显著差异。结论在以普通健康成年人为研究对象的低强度抗阻加压运动中,上肢压力为100~140 mmHg,下肢压力为140~180 mmHg的血流限制条件下,肌肉肿胀效应更加显著,生长激素、血睾酮等与增肌效果密切相关的合成类激素指标显著增加,同时疲劳感相对较小。  相似文献   

11.
The purpose of this study was to investigate whether using different focus affects electromyographic (EMG) amplitude and contraction duration during bench press performed at explosive and controlled speeds. Eighteen young male individuals were familiarized with the procedure and performed the one-maximum repetition (1RM) test in the first session. In the second session, participants performed the bench press exercise at 50% of the 1RM with 3 different attentional focuses (regular focus on moving the load vs contracting the pectoralis vs contracting the triceps) at 2 speed conditions (controlled vs maximal speed). During the controlled speed condition, focusing on using either the pectoralis or the triceps muscles increased pectoralis normalized EMG (nEMG) by 6% (95% CI 3–8%; p = 0.0001) and 4% nEMG (95% CI 1–7%; p = 0.0096), respectively, compared with the regular focus condition. Triceps activity was increased by 4% nEMG (95% CI 0–7%; p = 0.0308) at the controlled speed condition during the triceps focus. During the explosive speed condition, the use of different focuses had no effect. The different attentional focus resulted in comparable contraction duration for the measured muscles when the exercise was performed explosively. Using internal focus to increase EMG amplitude seems to function only during conditions of controlled speed.  相似文献   

12.
This study aimed to examine the reliability of different power and velocity variables during the Smith machine bench press (BP) and bench press throw (BPT) exercises. Twenty-two healthy men conducted four testing sessions after a preliminary BP one-repetition maximum (1RM) test. In a counterbalanced order, participants performed two sessions of BP in one week and two sessions of BPT in another week. Mean propulsive power, peak power, mean propulsive velocity, and peak velocity at each tenth percentile (20–70% of 1RM) were recorded by a linear transducer. The within-participants coefficient of variation (CV) was higher for the load–power relationship compared to the load–velocity relationship in both the BP (5.3% vs. 4.1%; CV ratio = 1.29) and BPT (4.7% vs. 3.4%; CV ratio = 1.38). Mean propulsive variables showed lower reliability than peak variables in both the BP (5.4% vs. 4.0%, CV ratio = 1.35) and BPT (4.8% vs. 3.3%, CV ratio = 1.45). All variables were deemed reliable, with the peak velocity demonstrating the lowest within-participants CV. Based upon these findings, the peak velocity should be chosen for the accurate assessment of BP and BPT performance.  相似文献   

13.
The present study investigated the effects of different intensities of resistance training (RT) on elbow flexion and leg press one-repetition maximum (1RM) and muscle cross-sectional area (CSA). Thirty men volunteered to participate in an RT programme, performed twice a week for 12 weeks. The study employed a within-subject design, in which one leg and arm trained at 20% 1RM (G20) and the contralateral limb was randomly assigned to one of the three conditions: 40% (G40); 60% (G60), and 80% 1RM (G80). The G20 started RT session with three sets to failure. After G20 training, the number of sets was adjusted for the other contralateral limb conditions with volume-matched. CSA and 1RM were assessed at pre, post-6 weeks, and post-12 weeks. There was time effect for CSA for the vastus lateralis (VL) (8.9%, 20.5%, 20.4%, and 19.5%) and elbow flexors (EF) (11.4%, 25.3%, 25.1%, and 25%) in G20, G40, G60, and G80, respectively (p?>?.05). G80 showed higher CSA than G20 for VL (19.5% vs. 8.9%) and EF (25% vs. 11.4%) at post-12 weeks (p?p?相似文献   

14.
The aim of this study was to compare the effect of 6 weeks of resistance training to volitional failure at low (30% 1 repetition maximum (RM)) or high (80%1RM) loads on gains in muscle size and strength in young women. Thirteen women (age: 29.7 ± 4.7years; height 166.7 ± 6.4cm; weight 64.2 ± 12.2kg) completed 2 training sessions per week for 6 weeks and muscle strength (1RM), muscle thickness (ultrasound) were measured before and after training. Training comprised 1 set to volitional failure of unilateral leg extensions and bicep curls with each limb randomly assigned to train at either 80% 1RM or 30% 1RM. Increases in muscle thickness [arms: 6.81 ± 3.15% (30% 1RM), 5.90 ± 3.13% (80% 1RM) and legs: 9.37 ± 5.61% (30% 1RM), 9.13 ± 7.9% (80% 1RM)] and strength [arms: 15.4 ± 12.2% (30% 1RM), 18.26 ± 12.2% (80% 1RM) and legs: 25.30 ± 18.4 (30% 1RM), 27.20 ± 14.5 (80% 1RM)] were not different between loads. When resistance exercise is performed to volitional failure gains in muscle size and strength are independent of load in young women.  相似文献   

15.
ABSTRACT

The purpose of this study was to examine load-dependent differences in lower-extremity biomechanics between the back squat (BS) and front squat (FS) exercises. Eleven NCAA Division-I athletes performed three repetitions of the BS and FS at loads of 40%, 60%, and 80% of their FS one repetition maximum (FS-1RM). Kinematic and kinetic data were collected during each squat repetition and used to calculate lower extremity peak joint angles and peak net joint moments (NJM). Peak angles and NJM were compared with a 2 × 3 repeated measures ANOVA. Peak hip extensor NJM were greater during the BS at 60% and 80% of FS-1RM. In comparison, peak knee extensor NJM were greater during the FS at 80% of FS-1RM. However, regression-based prediction of NJM at 100% of FS and BS 1RM indicated that at maximal loads, peak knee NJM are (~3%) higher during the BS. The experimental results suggest that when performed at the same absolute load, the BS and FS are characterized by greater respective mechanical demands imposed on the hip and knee extensors muscles groups. However, prediction-based results suggest that the knee extensor NJM demands are comparable when performed at the same relative load (i.e., with respect to each exercise’s RM).  相似文献   

16.
ABSTRACT

The velocity and magnitude in which the eccentric phase of an exercise is completed directly affects performance during the concentric phase. Therefore, the purpose of this research was to investigate the effects of eccentric phase duration on concentric outcomes at 60% and 80% of one-repetition maximum (1RM) in the squat and bench press. Sixteen college-aged, resistance-trained males completed 1RM testing, established normative eccentric durations, and performed fast (0.75 times normative) and slow (2.0 times normative) metronome-controlled eccentric duration repetitions. Outcome measures assessed during the concentric phase were: average concentric velocity (ACV), peak concentric velocity (PCV), rating of perceived exertion (RPE), range of motion (ROM), and barbell path. Eccentric duration was significantly and inversely correlated with ACV at 60% (r = ?0.408, p = 0.004) and 80% (r = ?0.477, p = 0.001) of 1RM squat. At 60% of 1RM squat, both fast and slow eccentric conditions produced greater (p < 0.001) PCV than normative duration with fast also producing greater PCV than slow (p = 0.044). Eccentric duration had no impact on RPE, ROM, or barbell path. Our results report for the first time that resistance-trained males performing a deliberately faster eccentric phase may enhance their own squat and bench press performance.  相似文献   

17.
The present study aimed (1) to assess the validity and reliability of the Borg category-ratio (CR-10) scale for monitoring exercise intensity in women with fibromyalgia (FM) and (2) to examine whether women with FM can discriminate between perceived exertion and exercise-induced pain. Thirty-three women with FM performed two incremental treadmill tests (1 week separated). Heart rate, oxygen uptake, minute ventilation and respiratory quotient were measured. The ratings of perceived exertion (RPE: CR-10 scale) and exercise-induced pain were obtained at each workload. The Spearman’s correlation of RPE with the physiological responses ranged from 0.69 to 0.79. The regression models explained ~50% of the variability of the studied physiological responses. We found “perfect acceptable” agreement in 69% of the observations. Weighted Kappa was 0.66 (95% confidence interval [CI]: 0.59–0.72). There were differences between RPE and pain at workloads 3 (1.50; 95%CI: 0.85–2.16), 4 (2.10; 95%CI: 1.23–2.96), 5 (3.40; 95%CI: 1.29–5.51) and 6 (3.97; 95%CI: 1.61–6.33). The main findings of the present study suggest that the Borg CR-10 scale is valid and moderately reliable for monitoring exercise intensity in women with FM, and these patients were able to discriminate between exertion and exercise-induced pain.  相似文献   

18.
目的:探讨主观感觉疲劳量表(RPE)是否适用于中老年肥胖患者运动处方实施过程中运动强度的监控并分析影响RPE的相关因素。方法:215名中老年肥胖患者,进行递增负荷实验测试功能能力(F.C.,单位为代谢当量METs)和相应的RPE。以70%F.C.完成一次中等强度运动,同时记录患者的RPE值,比较用RPE推测的METs值和用递增负荷实验测得的METs值之间的差别。结果:受试者平均F.C.为6.1±1.8(METs),对应的RPE为15.2±1.6。RPE与BMI、性别、教育程度和抗心律失常药物有一定关联。70%F.C.为4.9±1.1(METs),而用RPE计算的预测值为5.6±1.2(METs),后者较前者高23.1%(P<0.01)。结论:在中老年肥胖患者实施运动处方的过程中,使用RPE会过高估计其实际运动强度;BMI、性别、教育程度和使用抗心律失常药物是RPE的影响变量。  相似文献   

19.
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20.
Abstract

Exercise to failure results in similar muscle protein synthesis responses, independent of intensity. However, low-intensity exercise likely requires more repetitions and individuals with injuries may be incapable of sustaining the mechanical stress to reach failure. The aim of this study was to determine if knee wraps provide a stimulus to decrease time to failure. Twenty healthy individuals participated in a randomized crossover study consisting of three trials. The first trial was used to determine one-repetition maximum (1-RM) on leg extension. Participants were then assigned to a blood flow restriction or control group. After trial 2, participants crossed over to the opposite trial. Knee wraps were placed around the upper thigh of each leg during blood flow restriction. Leg extensions were completed at 30% 1-RM until failure. A rating of perceived exertion was taken after exercise and whole blood samples were taken before, after, and 3 min after exercise for the determination of lactate. Repetitions until failure and total work were significantly lower with practical blood flow restriction compared with the control trial. Metabolic stress as measured by whole blood lactate was higher immediately after muscular failure in the control compared with the blood flow restriction trial, but not so 3 min after exercise. There were no differences in ratings of perceived exertion. In conclusion, knee wraps provide a stimulus for blood flow restriction allowing failure to occur sooner with similar metabolic stress after reperfusion. However, similar perceptual responses despite the lower workload with blood flow restriction may limit its application to the highly motivated.  相似文献   

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