冷水浴对短跑运动员离心运动后DOMS症状的干预效果研究

目的:探究冷水浴对延迟性肌肉酸痛(DOMS)患者膝关节本体感觉的干预效果及作用机制。方法:采用随机对照试验,24名男性二级短跑运动员随机分为冷水浴干预组(n=12)和静坐对照组(n=12)。经离心运动诱发下肢肌群出现DOMS,静坐休息5min后进行冷水干预或静坐。分别在运动前、运动后24h、48h、72h、96h测量受试者的左大腿围度、自觉疼痛程度、左腿股四头肌最大等长肌力以及左腿膝关节本体感觉(位置觉+肌肉力觉)。在运动前、运动后即刻(0min)、5min、10min、15min分别测量血乳酸值。结果:(1)离心运动后即刻,两组大腿围度均显著性增加(P<0.05),运动后24h、48h、72h,CWI组的左大腿围度显著低于CON组(P<0.01);(2)离心运动后即刻,两组自觉疼痛程度均显著性增加,运动后24h、72h,CWI组的疼痛程度显著性低于CON组(P<0.01);(3)离心运动后即刻,两组血乳酸值均出现显著性上升(P<0.05),运动后0min~15min,两组间无显著性差异(P>0.05);(4)离心运动后即刻,两组的左腿MVIC均出现显著性下降(P<0.05),运动后24h~96h,CWI组MVIC显著高于CON组(P<0.01),(5)离心运动后即刻,两组左腿的本体感觉(主、被动位置觉、肌肉力觉)均出现显著性下降(P<0.05);运动后24h~96h,CWI组的主动位置觉显著高于CON组(P<0.01),运动后72h,CWI组的被动位置觉显著低于CON组(P<0.01),其他时间点(24h、48h、96h)无显著性差异(P>0.05),运动后24h~96h,CWI组的肌肉力觉显著高于CON组(P<0.01)。结论:冷水浴是运动训练或比赛后快速减轻DOMS症状的有效手段,有利于肌肉肿胀的恢复、减轻疼痛感、促进工作肌肉最大等长肌力及该肌肉所附着关节的本体感觉的恢复,总体有利于减轻DOMS症状。     

冷敷对大学生运动后延迟性肌肉酸痛的影响

采取实验观察法观察冷敷疗法对大学生延迟性肌肉酸痛的影响,采用蛙跳方法诱发受试者产生延迟性肌肉酸痛,并分析冷敷疗法对延迟性肌肉酸痛的减轻和消除的效果,为延迟性肌肉酸痛的减轻和消除寻求有效方法.实验通过蛙跳诱发受试者在运动后24h产生的DOMS,采用主观六级疼痛评定法量化受试者的疼痛程度.可以得出结论大学生受试者产生DOMS后,冷敷对肌肉围度和肌肉状态没有影响,但能有效地缓解受试者DOMS的主观疼痛.     

联合抗氧化剂对运动员DOMS和血IL-6、CK、CK-MM等水平的影响

目的 观察联合抗氧化剂对运动员一次性大强度离心运动后不同时相下肢肌肉疼痛等级和血IL-6、CK、CK-MM、LDH的影响,探讨联合抗氧化剂减缓运动员运动延迟性肌肉酸痛(DOMS)的作用和机制.方法 运动员16名,随机均衡分为对照组(A组)和联合抗氧化剂组(B组),运动前2周至运动后2天每天分别口服安慰剂或VE、VC与Se组成的联合抗氧化剂.服药两周后进行一次大强度离心跑台运动,建立DOMS模型,在服药前、运动前和运动后即刻、24 h、48 h分别测定运动员肘正中静脉血IL-6、CK、CK-MM、LDH水平及运动后相应时相下肢肌肉酸痛程度.结果 (1)运动员运动后下肢肌肉酸痛程度逐日加重,B组运动后各时相酸痛程度均显著轻于A组.(2)B组血浆IL-6运动后各时项均低于A组同时项,其中运动后24 h呈非常显著性差异.(3)B组血清CK、CK-MM运动后各时相均低于A组,其中运动后48 h二指标活性显著低于A组.(4)B组血清LDH运动后各时相均低于A组.结论 联合抗氧化剂能有效减轻大强度离心运动导致的运动应激和炎症反应,保护肌细胞膜的完整性,减轻DOMS.     

全身震动训练对离心运动诱导的延迟性肌肉酸痛影响

目的：研究离心运动前使用全身振动训练对 DOMS 预防的影响。方法：随机对照研究,30 名专业散打运动员随机分为全身振动训练组（n=15）和对照组（n=15）。受试者：优势腿膝伸肌在功率计上完成 6 组 10 次最大等速（60 °/s）离心收缩。全身振动训练组,受试者在振动平台上进行训练,25Hz,5 mm 峰值,离心运动前膝关节 100°屈曲 60 s。对照组不进行振动训练。结果：记录运动后第 1、2、3、4、7 和 14 天的肌肉酸痛、大腿围、压痛阈,测量血清肌酸激酶的基础值和运动后第 1、2、7 天的值。与对照组相比,肌酸激酶水平较低,压痛阈和肌肉酸痛较低,DOMS 症（不顺通）状减轻（P<0.05）,但是对大腿围没有明显的影响。结论：离心运动前,全身振动训练可能通过改善肌肉功能而降低 DOMS,还需要进一步研究以确定全身振动训练组降低运动员 DOMS 的作用。     

普拉提对慢性非特异性颈痛的疗效研究

目的:探讨普拉提运动对慢性非特异性颈痛患者的影响。方法:42名符合条件的受试者被随机分置于实验组(n=21),给予每周3次,为期6周的普拉提干预,对照组(n=21)不进行任何干预,实验前和实验结束后24h内进行相关指标的测量。结果:疼痛指标两组具有非常显著性差异(P<0.01),实验组疼痛下降明显;功能障碍指数组间具有非常显著性差异(P<0.01);SF-36中对身体疼痛和精力的影响组间具有非常显著性差异(P<0.01),生理机能、生理职能、一般健康状况、社会功能、情感职能、心理健康方面具有显著性差异(P<0.05)。结论:普拉提运动对慢性非特异性颈痛患者的治疗具有积极疗效。     

大蒜素与联合抗氧化剂干预对运动员DOMS和血浆IL-6水平变化的影响

目的:探讨大蒜素与联合抗氧化剂干预对运动员大强度离心运动后不同时相肌肉酸痛程度、血浆白细胞介素6(IL-6)水平变化的影响.方法:运动员 24 名,随机均衡分为对照组(A组)、联合抗氧化剂组(B组)和大蒜素组(C组),运动前2周至运动后2天每天分别口服安慰剂、联合抗氧化剂或大蒜素肠溶胶丸.服药两周后进行一次大强度离心跑台运动,建立运动员运动延迟性肌肉酸痛(DOMS)模型,在服药前、运动前和运动后即刻、24 h、48 h分别测定运动员肘正中静脉血IL-6浓度及运动后相应时相肌肉酸痛程度.结果:3组运动员运动后肌肉酸痛程度均呈延迟性,B、C组运动员运动后各时相肌肉酸痛程度与血浆IL-6浓度均低于A组同时相.C组运动员肌肉酸痛程度运动后各时相均高于B组同时相,而血浆IL-6的浓度运动后各时相均低于B组同时相,但均无显著性差异.结论:联合抗氧化剂与大蒜素均可减轻运动员离心运动导致的DOMS,抑制IL-6的产生;大蒜素可能通过降低运动应激,减小肌纤维损伤与炎症反应等作用,抑制运动后血浆IL-6浓度的升高;联合抗氧化剂可通过几种抗氧化成分的协同作用,减轻大强度离心运动导致的DOMS.     

冷热水交替浴对短跑运动员增强式运动后膝关节本体感觉的影响

目的：探究冷热水交替浴(CWT)对短跑运动员增强式运动后膝关节本体感觉的影响。方法：16名受试者随机分为冷热水交替浴组(CWT组)与静坐休息对照组(CON组),在执行10组每组20次负重(10 kg)浅蹲跳和50 m蛙跳的运动方案后,静坐休息5 min,分别采用14 min CWT或14 min静坐休息的干预手段。在运动前,运动后24 h、48 h、72 h、96 h不同时间点分别测量受试者的膝关节位置觉肌肉力觉以及肢体下落时关节反应角度。结果：(1)所有受试者在运动后均出现了主、被动位置觉,肌肉力觉的显著下降以及肢体下落时关节反应角度的显著上升(P＜0.05);(2)运动后24 h、48 h、72 h、96 h,CON组的主动位置觉显著低于CWT组(P＜0.01),运动后48 h,CON组的被动位置觉显著低于CWT组(P＜0.01);(3)运动后24 h、48 h、36 h、72 h,CON组的肌肉力觉显著低于CWT组(P＜0.01);(4)运动后24 h、48 h,CON组的肢体下落时关节反应角度显著大于CWT组(P＜0.01)。结论：本研究所设计的CWT方案可以有效缓解增强式运动中因肌肉离心所致的肌肉力觉的下降,促进肌肉本体感觉(主、被动位置觉,肢体下落时关节反应角度)的恢复。CWT恢复关节本体感觉的机制与促进肌力恢复、镇痛、加速代谢产物清除、缓解中枢神经系统疲劳等有关。     

运动所致迟发性肌肉酸痛的机制

所谓迟发性肌肉酸痛(DOMS)就是进行不习惯运动以后1—5天在肌肉所发生的疼痛和僵硬的感觉。DOMS能从两方面对肌肉运动能力产生有害影响,一方面由于随意用力的减弱,另一方面由于肌肉内部产生力量的能力下降,这种运动能力的下降是暂时的,不出现永久性损害。很多临床表现与DOMS有牵连,其中有血清酶的升高、肌红蛋白血症、肌肉组织学和超微结构的异常,而用力后骨骼肌溶解可能是DOMS的最严重形式。目前对DOMS最好的治疗方法是肌肉活动,虽然运动后这种感觉还会再现,对能引起DOMS的特殊收缩活动进行训练能减少酸痛的反映。DOMS的病因和细胞机制是不清楚的,但有很多假说解释这种现象,有如下的假说1)在肌肉收缩/弹性系统中,由于高张力(尤其伴随离心性运动)造成结构的损害。2)细胞膜的损害导致受害肌纤维Ca~(++)稳定状态的破坏,进而造成坏死,大约在运动后2天坏死达到高峰。3)巨噬细胞活动的产物和细胞内含物在间质中的堆积,刺激了肌肉中Ⅳ类感觉神经的游离神经末稍引起DOMS的感觉。     

大蒜素与联合抗氧化剂干预对运动员DOMS和CK-MM、CK等的影响

目的:探讨大蒜素与联合抗氧化剂干预对运动员大强度离心运动后不同时相肌肉酸痛程度、血CK-MM、CK、LDH活性的影响。方法:运动员24名,随机均衡分为实验对照组(A组)、联合抗氧化剂干预组(B组)和大蒜素干预组(C组),运动前2周至运动后2天每天分别口服安慰剂、联合抗氧化剂和大蒜素肠溶胶丸。服药两周后进行一次大强度离心跑台运动,建立运动员运动延迟性肌肉酸痛(DOMS)模型,在服药前、运动前和运动后即刻、运动后24h、运动后48h分别抽取各组运动员肘正中静脉血,测定CK-MM、CK、LDH活性及运动后相应时相肌肉酸痛程度。结果:三组运动员运动后肌肉酸痛程度均呈递增趋势,B、C组运动员运动后各时相肌肉酸痛程度与血CK-MM、CK、LDH活性均低于A组同时相。结论:大强度离心跑台运动可诱发运动员DOMS。大蒜素和联合抗氧化剂可减少运动员大强度离心运动后骨骼肌细胞内CK-MM、CK、LDH的大量逸出,对保护细胞膜完整性、降低运动应激程度、防治运动性骨骼肌微损伤有积极作用,可有效减轻运动员大强度运动后DOMS程度。     

冷水浸泡对运动后大鼠炎症反应的影响

目的探讨运动训练后进行冷水浸泡在促进机体恢复过程中是否会对机体炎症反应产生影响。方法 72只8周龄SD大鼠,对照组C组(n=24)、运动组E组(n=24)、运动冷水浸泡组CWI组(n=24),每组根据取材时间分为0h、24h、72h等小时组,运动组、运动冷水浸泡组的大鼠进行跑台离心运动,之后运动冷水浸泡组进行10℃冷水浸泡10min;Western Blot测腓肠肌TNF-α蛋白含量,ELISA测血浆中TNF-α含量。结果腓肠肌中TNF-α蛋白在C和E组之间均有显著性差异(p<0.01),在C和CWI组之间的0h、24h均有显著性差异(p<0.01),E和CWI组之间在0h未有差异(p>0.05);血浆中TNF-α在C和E、CWI组之间均有显著性差异(p<0.05或p<0.01),但E、CWI组之间仅在72h显著性差异(p<0.05)。结论运动后大鼠骨骼肌和血浆中TNF-α表达上调,运动后进行冷水浸泡在前期能够加强炎症反应,后期促使机体更快的恢复到正常水平,这可能是冷水浸泡促进机能恢复的部分原因。     

The effect of a prophylactic dose of flurbiprofen on muscle soreness and sprinting performance in trained subjects.

The aim of this study was to examine the effects of a prophylactic dose of a local, transcutaneously administered, non-steroidal anti-inflammatory drug on muscle soreness, muscle damage and sprinting performance in young trained males. Twenty-five subjects aged 19+/-3 years, actively participating in rugby union and field hockey, were familiarized with the test procedure and then divided at random into an experimental group (n = 13) and a control group (n = 12). The experimental group received two patches, each containing 40 mg flurbiprofen (TransAct LAT), 12 h before an exercise bout designed to produce delayed-onset soreness (DOMS). The control group received identical non-medicated placebo patches at the same time. Delayed-onset muscle soreness was induced by an exercise protocol consisting of drop jumps (seven sets of 10 repetitions). Serum creatine kinase activity, muscle soreness, muscle girth and acceleration in a maximal sprint over 30 m were measured before the induction of DOMS and at 12, 24, 48 and 72 h thereafter. Plasma lactate concentration was measured 3 min after the 30-m sprint tests. Subjects in both groups had significantly more pain at 24 and 48 h compared with at 12 and 72 h (P < 0.05; Friedman two-way analysis of variance). Thigh girth and serum creatine kinase did not change throughout the experiment. Although plasma lactate concentrations were elevated after the 30-m sprint, there were no differences between groups or as a result of DOMS. The greatest acceleration occurred between 5 and 10 m. This was not affected by the anti-inflammatory drug or DOMS. In conclusion, the aetiology of the DOMS induced in the trained subjects in this study seems to be independent of inflammatory processes or, more specifically, of increases in prostaglandin synthesis in the muscles.     

The Effects of Static Stretching and Warm-Up on Prevention of Delayed-Onset Muscle Soreness

Abstract

It has been suggested in the lay literature that static stretching and/or warm-up will prevent the occurrence of Delayed-Onset Muscle Soreness (DOMS). The primary purpose of this study was to determine the effects of static stretching and!or warm-up on the level of pain associated with DOMS. Sixty-two healthy male and female volunteers were randomly assigned to four groups: (a) subjects who statically stretched the quadriceps muscle group before a step, (b) subjects who only performed a stepping warm-up, (c) subjects who both stretched and performed a stepping warm-up prior to a step test, and (d) subjects who only performed a step test. The step test (Asmussen, 1956) required subjects to do concentric work with their right leg and eccentric work with their left leg to voluntary exhaustion. Subjects rated their muscle soreness on a ratio scale from zero to six at 24-hour intervals for 5 days following the step test. A 4×2×2 ANOVA with repeated measures on legs and Duncan's New Multiple Range post-hoc test found no difference in peak muscle soreness among the groups doing the step test or for gender (p > .05). There was the expected significant difference in peak muscle soreness between eccentrically and concentrically worked legs, with the eccentrically worked leg experiencing greater muscle soreness. We concluded that static stretching and!or warm-up does not prevent DOMS resulting from exhaustive exercise.     

The Decline of Women Leaders (Coaches and Athletic Directors) in Girls' Interscholastic Sport Programs in Virginia from 1972 to 1987

Abstract

The purpose of this study was to determine if static and baltislic stretching would, induce significant amounts of delayed onset muscle soreness (DOMS) and increases in creatine kinase (CK). Twenty males were randomly assigned to a static (STATIC) or ballistic stretching (BALLISTIC) group. All performed three sets of 17 stretches during a 90-min period, the only group difference being that STATIC remained, stationary during each 60-s stretch while BALLISTIC performed, boundng movements. Subjective ratings of DOMS (scale: 1–10) and serum CK levels were assessed before and every 24 hours post stretching, for 5 days. A repeated measures ANOVA revealed a significant main effect due to time (p < .05), with peak soreness occurring at 24 hours after (M = 2.8 ? 1.6). Surprisingly, a group effect (p < .05) demonstrated. that DOMS was significantly greater for STATIC than for BALLISTIC. At 24 hours there was a 62% (p < .05) increase in CK for combined groups. These findings indicate that similar bouts of static and ballistic stretching induce significant increases in DOMS and CK in subjects unaccustomed to such exercise. Furthermore, static stretching induced significantly more DOMS than did ballistic.     

Interferential therapy effect on mechanical pain threshold and isometric torque after delayed onset muscle soreness induction in human hamstrings

This study was undertaken to examine the acute effect of interferential current on mechanical pain threshold and isometric peak torque after delayed onset muscle soreness induction in human hamstrings. Forty-one physically active healthy male volunteers aged 18-33 years were randomly assigned to one of two experimental groups: interferential current group (n = 21) or placebo group (n = 20). Both groups performed a bout of 100 isokinetic eccentric maximal voluntary contractions (10 sets of 10 repetitions) at an angular velocity of 1.05 rad · s(-1) (60° · s(-1)) to induce muscle soreness. On the next day, volunteers received either an interferential current or a placebo application. Treatment was applied for 30 minutes (4 kHz frequency; 125 μs pulse duration; 80-150 Hz bursts). Mechanical pain threshold and isometric peak torque were measured at four different time intervals: prior to induction of muscle soreness, immediately following muscle soreness induction, on the next day after muscle soreness induction, and immediately after the interferential current and placebo application. Both groups showed a reduction in isometric torque (P < 0.001) and pain threshold (P < 0.001) after the eccentric exercise. After treatment, only the interferential current group showed a significant increase in pain threshold (P = 0.002) with no changes in isometric torque. The results indicate that interferential current was effective in increasing hamstrings mechanical pain threshold after eccentric exercise, with no effect on isometric peak torque after treatment.     

Effects of sensory-level high-volt pulsed electrical current ondelayed-onset muscle soreness

Ten healthy males and ten healthy females aged 21.5 +/- 3.2 years (mean +/- s) participated in the study, which was designed to evaluate the effectiveness of sensory level-high volt pulsed electrical current (HVPC) on delayed-onset muscle soreness (DOMS). Arm discomfort, elbow extension range of motion and isometric elbow flexion strength were obtained as baseline measurements. Delayed-onset muscle soreness was induced in the participants' dominant or non-dominant arm using two sets of 20 maximal eccentric elbow flexion contractions. After the induction of DOMS, the participants were randomly divided into an experimental condition (HVPC) or a placebo condition. The experimental condition consisted of 20 min of HVPC immediately after the induction of DOMS, and 20 min every 24 h for three consecutive days thereafter. The participants in the placebo condition received an intervention similar in design; however, no electrical current was administered. Baseline measurements were reevaluated at 24, 48, 72 and 96 h after the induction of DOMS. Three weeks later, the participants returned and the protocol was repeated on the contralateral limb, using the opposite intervention (HVPC or placebo). Repeated-measures analysis of variance revealed a significant increase in overall arm discomfort, decrease in elbow extension and decrease in isometric strength for both conditions over time. No significant main effect of treatment, or time-by-treatment interaction, was found for the HVPC condition when compared with the placebo condition for any variable. Sensory-level HVPC, as utilized in our application, was ineffective in reducing the measured variables associated with DOMS.     

Delayed Onset Muscle Soreness After Inspiratory Threshold Loading in Healthy Adults

Purpose: Skeletal muscle damage occurs following high-intensity or unaccustomed exercise; however, it is difficult to monitor damage to the respiratory muscles, particularly in humans. The aim of this study was to use clinical measures to investigate the presence of skeletal muscle damage in the inspiratory muscles. Methods: Ten healthy subjects underwent 60 minutes of voluntary inspiratory threshold loading (ITL) at 70% of maximal inspiratory pressure. Maximal inspiratory and expiratory mouth pressures, delayed onset muscle soreness on a visual analogue scale and plasma creatine kinase were measured prior to ITL, and at repeated time points after ITL (4, 24 and 48 hours post-ITL). Results: Delayed onset muscle soreness was present in all subjects 24 hours following ITL (intensity = 22 ± 6 mm; significantly higher than baseline p = 0.02). Muscle soreness was reported primarily in the anterior neck region, and was correlated to the amount of work done by the inspiratory muscles during ITL (r = 0.72, p = 0.02). However, no significant change was observed in maximal inspiratory or expiratory pressures or creatine kinase. Conclusions: These findings suggest that an intense bout of ITL results in muscle soreness primarily in the accessory muscles of inspiration, however, may be insufficient to cause significant muscle damage in healthy adults.Key Words: delayed onset muscle soreness, respiratory muscles, skeletal muscle damage     

Effects of sensory-level high-volt pulsed electrical current ondelayed-onset muscle soreness

Abstract

Ten healthy males and ten healthy females aged 21.5 ± 3.2 years (mean ± s) participated in the study, which was designed to evaluate the effectiveness of sensory level-high volt pulsed electrical current (HVPC) on delayed-onset muscle soreness (DOMS). Arm discomfort, elbow extension range of motion and isometric elbow flexion strength were obtained as baseline measurements. Delayed-onset muscle soreness was induced in the participants' dominant or non-dominant arm using two sets of 20 maximal eccentric elbow flexion contractions. After the induction of DOMS, the participants were randomly divided into an experimental condition (HVPC) or a placebo condition. The experimental condition consisted of 20 min of HVPC immediately after the induction of DOMS, and 20 min every 24 h for three consecutive days thereafter. The participants in the placebo condition received an intervention similar in design; however, no electrical current was administered. Baseline measurements were reevaluated at 24, 48, 72 and 96 h after the induction of DOMS. Three weeks later, the participants returned and the protocol was repeated on the contralateral limb, using the opposite intervention (HVPC or placebo). Repeated-measures analysis of variance revealed a significant increase in overall arm discomfort, decrease in elbow extension and decrease in isometric strength for both conditions over time. No significant main effect of treatment, or time-by-treatment interaction, was found for the HVPC condition when compared with the placebo condition for any variable. Sensory-level HVPC, as utilized in our application, was ineffective in reducing the measured variables associated with DOMS.     

The effects of topical Arnica on performance,pain and muscle damage after intense eccentric exercise

Abstract

The aim of the study was to determine if topical Arnica is effective in reducing pain, indicators of inflammation and muscle damage, and in turn improve performance in well-trained males experiencing delayed onset muscle soreness (DOMS). Twenty well-trained males matched by maximal oxygen uptake (V?O₂ Max) completed a double-blind, randomised placebo-controlled trial. Topical Arnica was applied to the skin superficial to the quadriceps and gastrocnemius muscles immediately after a downhill running protocol designed to induce DOMS. Topical Arnica was reapplied every 4 waking hours for the duration of the study. Performance measures (peak torque, countermovement and squat jump), pain assessments (visual analogue scale (VAS) and muscle tenderness) and blood analysis (interleukin-1 beta, interleukin-6, tumour necrosis factor-alpha, C-reactive protein, myoglobin and creatine kinase) were assessed at seven time points over five days (pre-, post-, 4, 24, 48, 72 and 96 hours after the downhill run). Participants in the topical Arnica group reported less pain as assessed through muscle tenderness and VAS 72 hours post-exercise. The application of topical Arnica did not affect any performance assessments or markers of muscle damage or inflammation. Topical Arnica used immediately after intense eccentric exercise and for the following 96 hours did not have an effect on performance or blood markers. It did however demonstrate the possibility of providing pain relief three days post-eccentric exercise.     

延迟性肌肉酸痛的研究进展

机体大强度或不习惯的运动,尤其是离心运动,常常会引起肌肉的延迟性酸痛,并在运动后的2~3天达到高峰,伴有一系列的肌肉结构、组织学及生物化学的改变,严重时会影响到人们体育健身及运动训练的效果。有关延迟性肌肉酸痛的研究已有百年的历史,但其产生的病因、机制等至今仍不完全清楚,也没有找到真正有效地清除或减轻肌肉酸痛的方法。通过对国内外相关文献的归纳、分析和综合,对运动性延迟性疼痛的产生机制及防治进展等进行广泛探讨,为体育健身和运动训练提供理论依据。     

Muscle soreness and serum enzyme activity following consecutive drop jumps

The purpose of this study was to evaluate changes in muscle soreness and serum enzyme activity following consecutive drop jumps. Seven male subjects (mean age 30.6 years) performed drop jumps from a 80-cm box height every 7 s until exhaustion (mean = 114 drop jumps). A questionnaire was used to assess muscle soreness (0 = no pain, 7 = unbearable painful) both pre- and post-exercise (0, 12, 24, 36 and 48 h, and 3, 4 and 5 days after the exercise). Blood samples were also taken from three subjects at each of these times. For the other four subjects, blood samples were taken pre-exercise and 0, 12 and 36 h and 5 days post-exercise only. Although there was large inter-subject variability in the development of muscle soreness, all the subjects reported muscle soreness in their lower extremity muscles, especially in the quadriceps femoris. Muscle soreness developed significantly (P less than 0.01) over time, its peak (mean +/- S.E. = 3.7 +/- 0.7) occurring 12-48 h post-exercise. Serum enzyme activity changed significantly over time (P less than 0.05), but the changes were small. Not one subject showed a large increase in creatine kinase, and the average increase was less than 1.3 times as much as the pre-exercise level throughout the period of study. These results suggest that the muscle damage that occurs after drop jumping is not associated with a large release of muscle enzymes into the blood, and muscle soreness is not necessarily related to enzyme elevation following drop jumps.