Exercise-induced hypoalgesia: Pain tolerance,preference and tolerance for exercise intensity,and physiological correlates following dynamic circuit resistance exercise

Previous research has demonstrated significant decreases in pain perception in healthy individuals following both aerobic and upper body resistance exercise, but research on circuit training has been limited. The purpose of the study was to determine the effects of a strenuous bout of dynamic circuit resistance exercise on pain threshold and pain tolerance in conjunction with changes in blood lactate levels, heart rate (HR), and perceived exertion. A sample of 24 college-age students participated in 2 sessions: (1) a maximal strength testing session and (2) a circuit training bout of exercise that consisted of 3 sets of 12 repetitions with a 1:1 work to rest ratio at 60% one-repetition maximum (1-RM) predicted from a three-repetition maximum (3-RM) for 9 exercises. Participants exhibited increases in pain tolerance, blood lactate levels, HR and perceived exertion following resistance exercise. Preference for exercise intensity was positively correlated with lactate post exercise and tolerance for exercise intensity was positively correlated with pain tolerance and lactate post exercise. In conclusion, this is the first study to demonstrate increases in pain tolerance following a dynamic circuit resistance exercise protocol and disposition for exercise intensity may influence lactate and pain responses to circuit resistance exercise.     

我国男子自由式摔跤运动员体能训练取得突破的关键点研究

运用专家咨询、调研、测试及元分析等方法,完成了对新一轮备战的中国国家男子自由式摔跤运动员的测试和数据收集,重点从身体机能训练(有氧与无氧训练)和力量训练两个方面论证了体能训练中应注意的几个关键问题。研究认为,1)就身体机能训练而言,实行"两极化"模式可能更优于"乳酸阈"模式,主要体现在有氧与无氧训练的强度和比例2个方面。2)运动员的有氧能力与功率下降率有着更为显著的相关性(r=-0.626,P=0.000),即有氧能力越强,功率下降率越低,通过元分析也进一步证实了有氧能力与功率保持能力的显著相关关系(总效应落在有效区内);3)力量训练方面应突出全面性(r最大力量=0.614,r力量耐力=0.532和r快速力量=0.511),但应在最大力量基础上发展快速力量。同时,也证实,最大力量和快速力量对运动水平存在显著的交互性作用(F=3.241,P=0.006,Et2α=0.176),进一步显示出单纯发展快速力量意义不大。4)我国男子自由式摔跤运动员在体能训练方法上应体现两点,一是需增加快速力量的训练手段,如增强式(plyometric)训练内容;二是注重不同部位的力量训练,如上肢体现出最大力量的特点,下肢体现出快速力量的特点。     

Acute caffeine ingestion enhances strength performance and reduces perceived exertion and muscle pain perception during resistance exercise

Abstract

The efficacy of caffeine ingestion in enhancing aerobic performance is well established. However, despite suggestions that caffeine may enhance resistance exercise performance, research is equivocal on the effect of acute caffeine ingestion on resistance exercise performance. It has also been suggested that dampened perception of perceived exertion and pain perception might be an explanation for any possible enhancement of resistance exercise performance due to caffeine ingestion. Therefore, the aim of this study was to examine the acute effect of caffeine ingestion on repetitions to failure, rating of perceived exertion (RPE) and muscle pain perception during resistance exercise to failure. Eleven resistance trained individuals (9 males, 2 females, mean age±SD=26.4±6.4 years), took part in this double-blind, randomised cross-over experimental study whereby they ingested a caffeinated (5 mg kg^?1) or placebo solution 60 minutes before completing a bout of resistance exercise. Experimental conditions were separated by at least 48 hours. Resistance exercise sessions consisted of bench press, deadlift, prone row and back squat exercise to failure at an intensity of 60% 1 repetition maximum. Results indicated that participants completed significantly greater repetitions to failure, irrespective of exercise, in the presence of caffeine (p=0.0001). Mean±S.D of repetitions to failure was 19.6±3.7 and 18.5±4.1 in caffeine and placebo conditions, respectively. There were no differences in peak heart rate or peak blood lactate values across conditions (both p >0.05). RPE was significantly lower in the caffeine compared to the placebo condition (p=0.03) and was significantly higher during lower body exercises compared to upper body exercises irrespective of substance ingested (p=0.0001). For muscle pain perception, a significant condition by exercise interaction (p=0.027) revealed that muscle pain perception was lower in the caffeine condition, irrespective of exercise. With caffeine, pain perception was significantly higher in the deadlift and back squat compared to the bench press. However, with placebo, pain perception was significantly higher for the deadlift and back squat compared to the prone row only. Therefore, acute caffeine ingestion not only enhances resistance exercise performance to failure but also reduces perception of exertion and muscle pain.     

综合力量训练对中国女子篮球运动员腰、膝、踝等速力量的影响

目的:了解在常规力量训练基础附加核心力量训练及振动训练方法对国家女子篮球队18名运动员腰背、膝关节、踝关节等速肌力的影响。方法:采用Pneu VIBE振动训练台对国家女子篮球运动员进行振动刺激力量训练,振动频率为25～40 Hz,同时进行核心区肌力训练。经过12周系统的力量训练,应用IsoMed 2000等速测试训练仪器对女子篮球运动员腰腹、膝、踝关节屈伸肌群进行等速力量测试分析。结果:经过12周综合力量训练,女子篮球运动员腰背等速肌力明显上升,屈肌峰力矩(PT)增加了14.35%,背伸肌力量增加了15.65%,差异具有显著性。而下肢力量膝关节峰力矩、屈伸肌峰力矩比率(H/Q)无显著变化。踝关节研究发现,左踝背屈峰力矩训练后稍有减弱,跖屈肌峰力矩以及跖屈/背屈比无显著变化。结论:在常规力量训练中增加先进的核心区训练可有效增加女子篮球运动员腰腹肌力,而振动训练以提高踝、膝关节肌力的方法的有效性需要进一步研究。     

Aerobic training alone or combined with strength training affects fitness in elderly: Randomized trial

Abstract

Purpose: To investigate if combined strength and aerobic training can enhance aerobic capacity in the elderly to a similar extent as aerobic training alone when training duration is matched. Methods: Elderly men and women (age 63.2?±?4.7) were randomized into two intervention groups: an aerobic group (AG, n?=?17) and a combined group (CG, n?=?16). Subjects trained 40?minutes three times a week for 12 weeks. Both groups trained 20 minutes at 65% of heart rate reserve on ergometer cycles followed by another 20 minutes on the ergometer cycles for AG and 20-minute strength training for the lower body for CG. The primary outcome was VO₂max. Secondary outcomes were maximal voluntary contraction (MVC) in isometric knee extension, 1 repetition maximum in three leg exercises, body fat, waist-to-hip ratio, blood pressure and score on the Health Survey Short Form 36 (SF-36). Results: Both groups improved VO₂max (p?<?.01) and MVC (p?<?.001). VO₂max increased 17% confidence interval (CI) [7.4–26] in CG and 26% CI [14.1–38.2] in AG, with no significant difference between groups. MVC increased 22% CI [16.3–27.7] in CG and 9% CI [4.6–13.5] in AG with CG improving MVC more than AG (p?<?.01). CG's score on the general health dimension on the SF-36 health survey improved more than AG's score. Conclusion: Elderly can substitute a part of their aerobic training with strength training and still improve VO₂max to a clinically significant degree when strength training is performed with large muscle groups subsequently to the aerobic training. Combined training additionally improves strength and self-assessed general health more than aerobic training alone.     

我国优秀皮划艇激流回旋运动员体能诊断与训练对策研究

以中国皮划艇激流回旋队9名国际健将级运动员为研究对象,对其最大摄氧量、心率、乳酸、卧推与卧拉的最大力量（1RM）及力量耐力（40% 1RM,120 s）、静水300 m直线速度、静水8 km长划等指标进行测试,采用SPSS25.0对测试结果进行描述统计,并与世界优秀选手相关体能指标进行比较,诊断我国优秀激流回旋运动员体能问题,并提出相应训练对策。结果表明,我国优秀激流回旋运动员有氧能力、专项力量、基础速度与专项速度不同程度落后于国际优秀选手。为提升我国优秀激流回旋运动员体能水平,建议采用水上与陆上相结合的有氧训练方法发展运动员有氧能力,提高全年有氧训练比例,科学安排有氧训练的负荷量与强度;采用陆上基础力量训练发展运动员上肢爆发力、力量耐力与躯干稳定性力量,采用水上专项力量训练发展运动员划桨的峰值桨力与功率;既要重视运动员静水划船的基础速度,也要强化其高强度、高速度的激流专项竞速能力。     

Part I: Biomechanics

The purpose of this study was to determine whether the sequence of strength training before endurance training (ST/ET) is more or less effective than endurance training followed by strength training (ET/ST). Twenty‐three females and 11 males were assigned to one of three groups: ST/ET (n= 15), ET/ST (n= 15) or control (n = 4). The 7‐week training programme consisted of strength training using 10 exercises for two sets of 3–12 repetitions and running for 20–25 min at 60–90% of heart rate reserve. Maximal oxygen uptake (VO₂ max) was measured during a graded treadmill test, and muscular strength was assessed using one‐repetition maximum tests for the bench press (BP), shoulder press (SP), arm curl (AC) and leg press (LP). The VO₂ max significantly (P < 0.05) increased 6.7 and 6.2% for the ST/ET and ET/ST groups, respectively. There was no significant (P > 0.05) difference between the two experimental groups. Muscular strength significantly (P <0.05) improved by 15.2% (BP), 16.6% (SP), 17.2% (AC) and 11.9% (LP) for the ST/ET group and 19.9% (BP), 24.1% (SP), 20.9% (AC) and 14.0% (LP) for the ET/ST group. There were no significant (P > 0.05) differences between the two experimental groups for the BP, AC and LP; however, the ET/ST group increased (P < 0.05) SP strength more than the ST/ET group. In conclusion, adaptations to a combination of short‐term endurance and strength training as assessed by VO₂ max and BP, AC and LP strength appear to be independent of whether endurance training occurs prior to or following strength training.     

Effect of two different intensity distribution training programmes on aerobic and body composition variables in ultra-endurance runners

The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO₂max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO₂max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.     

男子赛艇运动员与训练有关的有氧无氧能力和激素变化

观察了１５名男子赛艇运动员为期３０周训练中最大做功能力、最大乳酸值、最大摄氧量及心脏形态和功能的变化及相应时期的血清睾酮、游离睾酮、皮质醇的急慢性效应。在以力量训练为主的准备期，变化较小，以专项训练为主的准备期，心功能和有氧能力明显改善。最大负荷后及高强度训练１２周后，血清睾酮降低。提示在不同训练周期中力量—耐力训练应合理安排，有利于发挥机体适应能力。     

Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy

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   

Effects of aerobic versus resistance training on glycaemic control in men with type 2 diabetes

Abstract

The aim of this study was to compare the effects of aerobic training and resistance training on glycaemic control factors in men with type 2 diabetes. We performed a randomized clinical trial in which 26 men (age 57±8 years) with type 2 diabetes were randomly assigned to an aerobic training group or a resistance training group. The participants exercised three times a week for 12 weeks. Metabolic factors (haemoglobin A_1C; fasting glucose and C-peptide; total, LDL, and HDL cholesterol; triglycerides), blood pressure, body composition, maximum oxygen uptake, and muscular strength were measured before and after the intervention. Both training groups experienced significant improvements in haemoglobin A_1C: the aerobic training group saw a decrease in absolute values from 7.10±0.97% to 6.55±0.74% (P=0.001) and the resistance training group from 7.21±1.8% to 6.85±0.66% (P=0.024). Both training groups had significant improvements in systolic and diastolic blood pressure (P<0.05) and in several of the measured body composition variables (P<0.05). In conclusion, the aerobic and resistance training groups saw similar improvements in glycaemic control. This suggests that both aerobic training and resistance training have beneficial effects for men with type 2 diabetes.     

功能性与传统力量训练的训练效果比较研究——基于下肢运动生物力学、FMS和运动能力测试

该研究对40名自愿参与的男性大学生施加8周的功能性力量和传统力量训练,以期通过基于下肢运动生物力学、FMS和运动能力测试,探究功能性力量与传统力量的训练效果,进而为大学生进行功能性和传统力量训练提供理论依据与参考建议。研究分为实验组和对照组,对实验组进行了8周的功能性力量训练,对照组进行了8周的传统抗阻力量训练,并在训练前后分别进行了下肢内外翻力矩、FMS和运动能力测试。研究结论：（1）持续8周的功能性力量训练可以显著提高大学生的功能动作质量（FMS）,但与传统力量训练相比,并没有对功能动作质量的提高带来更显著的效果;然而对下肢运动生物力学的影响要显著优于传统力量训练。（2）持续8周的功能性力量训练与传统力量训练相比,更能提高大学生的速度能力、协调能力以及灵敏素质,然而其对下肢的弹跳能力的影响却远不如传统力量训练,弹跳能力仍需要进行大的抗阻力量训练才能得到显著提高。（3）功能性力量训练不能替代传统力量训练对于肌肉的力量、爆发力以及平衡能力的影响,因此,在力量训练时,应当考虑传统抗阻力量训练和功能性力量训练对运动能力的不同影响,有选择地进行训练。     

不同体育锻炼类型与大学生生命质量相关性分析

目的：探讨不同体育锻炼类型对大学生生命质量的影响,为推动高校体育教学改革,提高大学生生命质量提供参考。方法：随机抽取定西师范高等专科学校男女生各90名进行中等强度的力量和有氧耐力练习实验,采用SF-36量表进行调查分析。结果：被试18周后,大学生生命质量因子均不同程度的提高;不同性别,相同体育锻炼类型力量练习除生理功能和活力因子发生显著性变化外（P〈0．05）,其它因子变化均不明显;有氧耐力练习除生理功能、躯体疼痛、精神健康因子发生显著性变化外（P〈0．05）,其它因子变化均不明;相同性别,不同体育锻炼类型男生在社会功能、活力、精神健康因子有方差显著性差异（P〈0．05）;女子在生理功能、社会功能因子有方差显著性差异（P〈0．05）,在活力、精神健康因子有方差极显著性差异（P〈0．01）。结论：有氧耐力练习比力量练习更能提高大学生的生命质量。     

Longer-term effects of minimalist shoes on running performance,strength and bone density: A 20-week follow-up study*

This study investigated whether male runners improve running performance, running economy, ankle plantar flexor strength, and alter running biomechanics and lower limb bone mineral density when gradually transitioning to using minimalist shoes for 100% of weekly running. The study was a planned follow-up of runners (n?=?50) who transitioned to minimalist or conventional shoes for 35% of weekly structured training in a previous 6-week randomised controlled trial. In that trial, running performance and economy improved more with minimalist shoes than conventional shoes. Runners in each group were instructed to continue running in their allocated shoe during their own preferred training programme for a further 20 weeks while increasing allocated shoe use to 100% of weekly training. At the 20-week follow-up, minimalist shoes did not affect performance (effect size: 0.19; p?=?0.218), running economy (effect size: ≤?0.24; p?≥?0.388), stride rate or length (effect size: ≤?0.12; p?≥?0.550), foot strike (effect size: ≤?0.25; p?≥?0.366), or bone mineral density (effect size: ≤?0.40; p?≥?0.319). Minimalist shoes increased plantar flexor strength more than conventional shoes when runners trained with greater mean weekly training distances (shoe*distance interaction: p?=?0.036). After greater improvements with minimalist shoes during the initial six weeks of a structured training programme, increasing minimalist shoe use from 35% to 100% over 20 weeks, when runners use their own preferred training programme, did not further improve performance, running economy or alter running biomechanics and lower limb bone mineral density. Minimalist shoes improved plantar flexor strength more than conventional shoes in runners with greater weekly training distances.     

女子2000米赛艇运动员不同训练周期中有氧和无氧代谢能力变化

本文观察了16名女子赛艇运动员30周训练期间有氧和无氧代谢运动能力的变化。前13周以力量训练为主,后17周以专项训练为主。观察发现过多力量训练无助于有氧能力发展,在专项训练期,应保持足够强度才能在发展有氧能力的同时提高最大乳酸值。     

Unilateral and bilateral patellofemoral pain in young female dancers: Associated factors

ABSTRACT

Aiming to evaluate the prevalence of unilateral/bilateral patellofemoral pain (PFP) among young dancers, and to investigate whether different factors are associated with PFP in young dancers, 132 dancers aged 12–14 years were assessed for PFP. Anthropometric parameters, proprioception ability, dynamic postural balance (DPB), and muscle strength were measured. PFP was found in 64.1% of the dancers. No significant differences in the prevalence of dancers with no, unilateral, or bilateral PFP at different ages were found. Significant age effects were found for anthropometric and developmental measurements, and for intensity of training. PFP effect was found for DPB asymmetry, ankle proprioception, and leg-length %height. A higher hip abductor/adductor ratio was associated with PFP in 14-year-old dancers. Binomial logistic regression showed that increased number of hours per day (h/day) and decreased number of hours per week (h/week), low proprioception scores, greater leg length as %height, and more anterior DPB asymmetry were significant predictors of PFP. In conclusion: unilateral/bilateral PFP is common among young dancers. Body morphology, reduced ankle proprioception ability, DPB asymmetry, and increased h/day of practice are associated with PFP. Dance teachers should start monitoring the impact of training and implement injury modification/prevention strategies when their students are at a young age.     

The relationship between cardiac autonomic function and maximal oxygen uptake response to high-intensity intermittent-exercise training

Abstract

Major individual differences in the maximal oxygen uptake response to aerobic training have been documented. Vagal influence on the heart has been shown to contribute to changes in aerobic fitness. Whether vagal influence on the heart also predicts maximal oxygen uptake response to interval-sprinting training, however, is undetermined. Thus, the relationship between baseline vagal activity and the maximal oxygen uptake response to interval-sprinting training was examined. Exercisers (n?=?16) exercised three times a week for 12 weeks, whereas controls did no exercise (n?=?16). Interval-sprinting consisted of 20 min of intermittent sprinting on a cycle ergometer (8 s sprint, 12 s recovery). Maximal oxygen uptake was assessed using open-circuit spirometry. Vagal influence was assessed through frequency analysis of heart rate variability. Participants were aged 22 ± 4.5 years and had a body mass of 72.7 ± 18.9 kg, a body mass index of 26.9 ± 3.9 kg · m^?2, and a maximal oxygen uptake of 28 ± 7.4 ml · kg^?1 · min^?1. Overall increase in maximal oxygen uptake after the training programme, despite being anaerobic in nature, was 19 ± 1.2%. Change in maximal oxygen uptake was correlated with initial baseline heart rate variability high-frequency power in normalised units (r?=?0.58; P < 0.05). Thus, cardiac vagal modulation of heart rate was associated with the aerobic training response after 12 weeks of high-intensity intermittent-exercise. The mechanisms underlying the relationship between the aerobic training response and resting heart rate variability need to be established before practical implications can be identified.     

健美操运动对智障学生运动能力的影响——以自闭症、Down综合征和普通智障学生为例

运用实验法、观察法、测量法、数理统计法和对比分析法,对自闭症学生、Down综合征学生和普通智障学生进行16周的健美操训练。探讨其对三类学生的运动能力改善程度,为智力障碍学生探索新的积极有效的运动项目和锻炼途径。结果表明:健美操训练可以有效提高Down综合征学生、自闭症学生和普通智障学生的下肢力量和协调性;健美操训练对柔韧性和平衡能力的改善不显著;健美操可以显著提高学生整体运动能力。结论:健美操对Down综合征、自闭症和普通智障学生的运动能力有所提高,而且对于不同类型的学生,其提高程度及提高方面有所差异;健美操对Down综合征学生和自闭症学生的情绪改善明显。     

Analysis of the training load during a hypertrophy-type resistance training programme in men and women

Abstract

The purpose of this study was to analyze the specific training load during a resistance training (RT) programme designed to increase muscular hypertrophy in men and women. Thirty-four women (22.7 ± 4.1 years, 58.8 ± 11.9 kg, 162.6 ± 6.2 cm and 22.1 ± 3.6 kg.m^?2) and 30 men (22.7 ± 4.4 years, 68.4 ± 9.0 kg, 174.5 ± 6.6 cm and 22.5 ± 2.4 kg.m^?2) underwent a supervised RT programme that was divided into two phases of 8 weeks each. Training consisted of 10–12 exercises performed with three sets of 8–12 repetitions at repetition maximum resistances performed 3 times per week on nonconsecutive days. There was a significant (P < 0.05) main effect for gender by time interaction for average training load of all the exercises performed in the first 8 weeks of RT with women showing a higher relative increase than men (+43.6% vs. +32.5%, respectively). This result was not observed during the second 8-week phase of the RT programme during which no significant gender by time interaction (P > 0.05) was shown with both genders having a similar relative increase (+28.7% vs. +24.3%, respectively). Women had a higher increase than men in specific average training load of the upper limb exercises during both the first 8 weeks of training (+30.2% vs. +26.6%, respectively) and the second 8 weeks of training (+31.1% vs. +25.3%, respectively). We conclude that the adaptation in specific training load is influenced by gender.     

Heart rate and perceived muscle pain responses to a functional walking test in McArdle disease

Abstract

The aim of this study was to assess a 12-min self-paced walking test in patients with McArdle disease. Twenty patients (44.7 ±11 years; 11 female) performed the walking test where walking speed, distance walked, heart rate (HR) and perceived muscle pain (Borg CR10 scale) were measured. Median (interquartile range) distance walked was 890 m (470–935). From 1 to 6 min, median walking speed decreased (from 75.0 to 71.4 m?min^–1) while muscle pain and %HR reserve increased (from 0.3 to 3.0 and 37% to 48%, respectively). From 7 to 12 min, walking speed increased to 74.2 m?min^–1, muscle pain decreased to 1.6 and %HR reserve remained between 45% and 48%. To make relative comparisons, HR and muscle pain were divided by walking speed and expressed as ratios. These ratios rose significantly between 1 and 6 min (HR:walking speed P = .001 and pain:walking speed P < .001) and similarly decreased between 6 and 11 min (P = .002 and P = .001, respectively). Peak ratios of HR:walking speed and pain:walking speed were inversely correlated to distance walked: r_s (HR) = ?.82 (P < .0001) and r_s (pain) = ?.55 (P = .012). Largest peak ratios were found in patients who walked < 650 m. A 12-min walking test can be used to assess exercise capacity and detect the second wind in McArdle disease.