补充糖肽饮料对一次性抗阻训练人体运动能力和血液SOD、GSH-Px、T-AOC及MDA水平的影响

目的:观察补充糖肽饮料对一次性抗阻训练人体运动能力的影响,从血液抗氧化酶活性及自由基时相性变化的角度观察补充糖肽饮料对血液抗氧化能力的影响。方法:30名男性运动员随机分为服用大剂量糖肽饮料(HCP)、服用小剂量糖肽饮料(CP)、服用含糖对照饮料(CHO)三组,分别进行强度为80%、100%、100%8RM三个循环力量训练;第三个循环运动至力竭,并记录完成的动作次数。在运动前30 min(6 ml/kg)、第二个循环训练结束后(3 ml/kg)和第三个循环训练后(6 ml/kg),受试者分别摄取HCP(糖:肽=2:1)、CP(糖:肽=4:1)和CHO(单纯糖)饮料;分别于运动前、运动后即刻、运动后1 h、6 h、24 h取肘正中静脉血,测定血清SOD、GSH-Px活性及T-AOC、MDA水平。结果:第三个循环运动至力竭完成的单位瘦体重总负荷量组间差异无统计学意义;血清SOD活性、GSH-Px活性、T-AOC和MDA水平组间差异无统计学意义;血清T-AOC、MDA水平和SOD活性随时间变化的差异有统计学意义(P<0.01,P<0.05),GSH-Px活性无显著性差异。结论:一次性抗阻训练时补充糖肽饮料对人体运动能力影响不明显,提高人体血液抗氧化能力效果亦不明显。     

中药生脉饮对女子散打运动员夏训期体能与免疫功能的影响

目的:探讨夏训期服用中药生脉饮对女子散打运动员体能与免疫功能的调节机制。方法:14名女子散打运动员随机分为实验组和对照组,两组训练内容相同,实验组饮用含中药生脉饮40ml+酸梅汁160 ml的饮料,对照组只饮用酸梅汁饮料200 ml,每日上下午训练结束时各1次,持续4周。4周实验前后分别进行相关测试,包括体能测试、血常规、生化及免疫指标,采用日常训练状态监控测量表和RPE主观感觉疲劳程度评定量表进行日常机能监控。结果:饮用生脉饮4周后,实验组最大摄氧量、全力击打沙袋运动后7 min血乳酸值、IgG和IgM较实验前均有显著性差异(P<0.05);实验组和对照组肌酸激酶和血清睾酮实验前后差值比较有显著性差异(P<0.05)。日常训练状态监控测量表和RPE主观感觉疲劳程度评定量表数据显示两组运动员均未出现过度疲劳。结论:夏季饮用生脉饮对女子散打运动员有氧能力有一定的促进作用,对疲劳恢复有一定的调节作用;能提高运动员免疫球蛋白含量,一定程度上增强了机体的免疫力。     

补充糖肽饮料对一次性抗阻训练人体运动能力、糖代谢及血清嘌呤体浓度的影响

目的:观察补充糖肽饮料对一次性抗阻训练时人体运动能力、运动恢复和血液抗氧化能力的影响。方法:30名男性运动员随机分为HCP、CP、CHO三组,进行强度分别为最大强度为8RM的80%、100%和100%的三个循环力量训练(每个循环包括平板卧推、坐姿腿屈伸、重锤下拉、俯卧腿屈伸四个动作);第三个循环运动至力竭,并记录完成的动作次数。在运动前30min(6ml/kg)、第二个循环训练结束后(3ml/kg)和第三个循环训练后(6ml/kg),按不同分组受试者分别摄取HCP(糖∶肽=2∶1)、CP(糖∶肽=4∶1)和CHO(单纯糖)饮料;运动前、运动后即刻、运动后1h、6h、24h取肘正中静脉血,测定血糖、血乳酸、胰岛素及血清次黄嘌呤、黄嘌呤及尿酸的浓度。运动能力测试包括单位瘦体重负荷及运动至力竭所完成的单位瘦体重总负荷。结果:各组间运动能力无显著性差异。HCP组运动后1h血清胰岛素水平显著高于CHO组(P<0.05);而各时间点血糖、血乳酸及血清次黄嘌呤、黄嘌呤和尿酸浓度组间无显著差异。结论:一次性抗阻训练时补充不同比例的糖肽饮料和单纯含糖饮料对人体运动能力和黄嘌呤氧化酶途径自由基生成的影响无明显差异,补充糖肽比为2∶1的饮料可能有利于运动后机体的恢复。     

补充复合抗氧化剂对中长跑运动员身体机能的影响

目的 :观察运用复合抗氧化剂对耐力项目运动员促进体能恢复的作用。方法 :15名男性省级中长跑运动员随机分为对照组和实验组 ,进行为期 3周的大强度训练 ,实验组每天早晚各补充 10ml复合抗氧化剂“升态口服液” ,对照组服用安慰剂。分别测试受试对象实验前、后的乳酸无氧阈功率、心率恢复和血液生化指标。结果 :服用“升态口服液”后实验组的乳酸无氧阈功率明显提高 (P <0 0 1) ,而对照组则无显著变化。服用口服液 2周和 3周后实验组血清BUN水平明显低于对照组 (P <0 0 5 ) ;两组间及其组内不同时间的血清T水平无显著变化。对照组的CK活性实验后比实验前明显升高 (P <0 0 5 ) ;而实验组则无明显差异。实验组的LDH活性实验后明显低于实验前 (P <0 0 5 ) ,血清MDA浓度实验后明显低于实验前 (P <0 0 5 ) ,同时显著低于对照组 (P <0 0 5 )。对照组的血清SOD水平 ,实验后明显低于实验前 (P <0 0 5 ) ,而实验组无明显变化。提示服用“升态口服液”可降低运动后血清CK水平 ,促进中长跑运动员有氧能力提高 ,有效清除运动中产生的自由基 ,具有一定的抗疲劳作用。     

两周热环境训练结合营养干预对优秀女子网球运动员营养和机能状况的影响

目的:探讨高温、训练和营养干预对优秀女子网球运动员营养和机能状况的影响。方法:在2周热环境训练中对备战北京奥运会的8名国家队女子网球运动员进行营养干预,并在干预前(7月19日)和干预后(8月2日)测试其营养、形态和生化指标。结果:营养干预后,膳食总热能、碳水化合物和蛋白质摄入比例分别显著增加11.0%,3.2%和14.8%(P<0.05),均高于90%推荐值,脂肪摄入比例显著下降17.8%(P<0.05)。训练中补水、补糖和补盐量显著提高(P<0.05)。运动员瘦体重明显增加(P<0.05),体脂百分比显著降低(P<0.05)。血红蛋白、血尿素、肌酸激酶、睾酮和皮质醇指标维持正常。结论:合理膳食、营养补剂以及科学训练能改善网球运动员的营养和机能状况,有助于运动员热适应能力的提高。     

补充小麦肽对预防散打运动员发生过度训练的作用

目的:研究小麦肽预防散打运动员发生过度训练的干预效果。方法:将扬州大学33名高水平散打运动员随机分为对照组、小麦肽低剂量组(3g)、中剂量组(6g)和高剂量组(9g),于每次大负荷散打训练后分别补充安慰剂和低、中和高剂量小麦肽,实验前后分别测定各组体重、握力、腿部肌力、反应时以及血清肌酸激酶(CK)活性、睾酮(T)和皮质醇(C)含量。结果:(1)6周大负荷散打专项训练后,对照组体重、握力均显著下降,反应时显著延长,血清CK活性显著上升,T含量显著降低,C含量虽有升高,但无统计学意义。(2)在大负荷散打训练后补充不同剂量的小麦肽在一定程度上能减轻体重的降低和血清CK活性的升高;与训练前相比,小麦肽低剂量组除了腿部肌力显著增加和血清C显著降低外,其它指标均无显著性变化;中剂量组握力、腿部肌力和血清T含量显著增加,反应时和血清C含量显著降低;高剂量组除握力和腿部肌力显著增加外,其它指标均无显著性变化。从训练前后各指标的变化量来看,与对照组相比,低剂量组握力、腿部肌力显著增加,血清C含量显著降低,血清CK活性增加的幅度显著减小;中剂量组的体重、握力、腿部肌力、血清T含量均显著增加,反应时、血清CK活性、C含量均显著降低;高剂量组除握力、腿部肌力显著增加、反应时显著降低外,其它指标均无显著性差异。结论:6周的大负荷运动训练使散打运动员产生过度训练,而在大负荷散打训练时补充不同剂量的小麦肽均可有效减轻肌肉损伤,加速运动性疲劳的恢复,对防止过度训练的发生具有一定作用,其中以补充中剂量(6g)小麦肽的效果最好。     

耐力训练和益气补肾中药对睾酮合成的调节因素--StAR蛋白和P450SCC酶mRNA表达的影响

目的:探讨运动训练和益气补肾中药对影响睾酮合成的StAR蛋白和P450SCC酶的作用.方法:50只雄性Wistar大鼠随机分为安静对照组(n=10)、安静服药组(n=10)、耐力训练组(n=15)和训练服药组(n=15).经6周递增负荷游泳训练后,采用放免法测定大鼠血清睾酮水平,利用RT-PCR方法检测大鼠睾丸StAR和P450SCC mRNA的表达水平.结果:(1)训练组大鼠血清睾酮水平显著降低,而训练服药组大鼠的血清睾酮水平则未降低.(2)未服药训练大鼠的StAR mRNA水平比安静对照组明显下降(P<0.01);服用中药的安静大鼠和运动大鼠的StAR mRNA表达比安静对照组和训练组显著增强(P均小于0.001).(3)训练组和训练服药组大鼠P450SCC mRNA水平均显著低于安静对照组和安静服药组(P<0.05).结论:(1)研究结果提示长期大负荷训练后大鼠睾丸间质细胞StAR mRNA表达下降,益气补肾中药对StAR mRNA的表达转录水平有增强作用.长期大负荷运动造成的血清睾酮水平下降与StAR mRNA的表达强弱有关.(2)长期大负荷运动可造成大鼠睾酮合成限速酶P450SCC mRNA表达降低,益气补肾中药可维持血清睾酮水平,但其在mRNA水平对P450SCC的表达无明显效应,其对睾酮合成酶的影响仍需进一步探讨.     

中药消除运动性疲劳临床研究之二——内服中药“肾王膏”消除男子摔跤运动员运动性肾阴不足临床疗效观察

目的:观察自制内服中药"肾王膏"对男子摔跤运动员运动性肾阴不足的治疗效果。方法:选择88名男子摔跤运动员随机分为三组(实验组、阳性对照组和空白对照组)、两个中心进行观察。实验在训练周期中大强度运动训练期间(冬训)进行,连续20天。实验组采用内服药物为干预手段,阳性对照组采用目前运动队常用的提高睾酮的营养补剂,空白对照组采用安慰剂。检测实验期间(实验前,训练第10天,训练第20天)血清睾酮、皮质醇、血红蛋白(Hb)和红细胞(RBC)、主观疼痛度评分(VAS)、主观体力感觉等级(RPE)量表等指标的变化。结果:(1)样本脱落9人,共79人进入最后观察。(2)各组实验前后RPE结果无差异;实验组训练第20天VAS评分显著低于实验前,空白对照组训练第10天显著低于实验前,阳性对照组实验前后差异无显著性。(3)实验组血睾酮第20天较实验前显著上升,阳性对照组第10天较实验前显著下降,空白对照组第20天较实验前显著下降。实验前后各组皮质醇、睾酮/皮质醇比值无差异。(4)阳性对照组RBC第10天较实验前显著下降,实验组和空白对照组实验前后无差异,各组Hb实验前后均无差异。结论:内服中药"肾王膏"有在大强度训练期间稳定运动员血清睾酮的作用,能一定程度消除体能性运动疲劳。     

补充强化多肽片对耐力训练大鼠游泳力竭时间、肌糖原及血清T、BU、CK的影响

目的:探讨强化多肽片对耐力训练大鼠运动能力及疲劳恢复的影响。方法:将Wistar大鼠随机分为5组:安静对照组(n=12)、运动对照组(n=11)、高剂量强化多肽片(1.6mg/gBW/d)运动组(n=12)、中剂量强化多肽片(0.8mg/gBW/d)运动组(n=12)、低剂量强化多肽片(0.4mg/gBW/d)运动组(n=12)。采用递增负荷游泳运动方案,每周训练5天,上、下午各一次,游泳时间从第1周的20min/次增加至第6周的85min/次,共训练6周,第6周最后一次训练时令各运动组采用5%体重负荷游泳至力竭,记录力竭游泳时间。24小时后断头取血和股四头肌,检测血睾酮(T)、血尿素(BU)、肌酸激酶(CK)和肌糖原(MG)。结果:(1)中剂量强化多肽片运动组力竭运动时间显著长于运动对照组(P<0.01);高、中、低剂量多肽片运动组MG含量显著高于运动对照组(P<0.01,P<0.05)。(2)与安静对照组相比,运动对照组血T值显著降低(P<0.05),但高、中、低剂量多肽片运动组与安静对照组、运动对照组相比均无显著性差异(P>0.05);运动对照组血BU值显著高于安静对照组(P<0.01),中、低剂量多肽片运动组显著低于运动对照组(P<0.05);运动对照组血CK活性显著高于安静对照组(P<0.01),中、高剂量多肽片运动组较运动对照组显著下降(P<0.01)。结论:补充中剂量强化多肽片能延长大鼠力竭游泳时间,增加骨骼肌糖原含量,降低血清肌酸激酶和尿素水平,提示补充适宜剂量的强化多肽片有提高耐力训练大鼠运动能力和促进疲劳恢复的作用。     

6周负重跑训练和补充大豆多肽对D-半乳糖衰老大鼠骨骼肌IGF-I mRNA和GDF-8 mRNA表达的影响

目的:探讨6周负重跑训练和补充大豆多肽对衰老大鼠骨骼肌IGF-I mRNA和GDF-8 mRNA表达的影响。方法:56只雄性SD大鼠随机分为7组:成年组,模型组,大负重组,小负重组,补肽组,补肽+大负重组和补肽+小负重组。除成年组外,其余各组大鼠采用6周D-半乳糖皮下注射复制亚急性骨骼肌衰老模型,同时按分组分别施加大(70%最大负重)、小(30%最大负重)两种负重方式的跑台训练或/和补充15%大豆多肽的干预。6周实验结束后禁食12小时,处死所有大鼠,无菌取材,测试骨骼肌IGF-I mRNA和GDF-8mRNA表达量。结果:与成年组相比,模型组骨骼肌IGF-I mRNA表达显著下降(P<0.01),GDF-8 mRNA表达显著升高(P<0.01),负重或补肽单独干预及其联合干预均可有效逆转以上趋势(P<0.01),并且负重和补肽两者具有显著交互作用。结论:负重跑训练或补充大豆多肽干预,可有效改善衰老大鼠骨骼肌IGF-I mRNA低表达和GDF-8 mRNA高表达,并且两种手段联合运用也可达到相同效果。     

Hormonal and metabolic response in elite female gymnasts undergoing strenuous training and supplementation with SUPRO Brand Isolated Soy Protein

BACKGROUND: This study evaluates the metabolic and hormonal response in elite female gymnasts undergoing strenuous training and supplementation with SUPRO Brand Isolated Soy Protein. METHODS. EXPERIMENTAL DESIGN: 14 top female gymnasts (Romanian Olympic Team), took part in a study to examine their hormonal metabolic profile and to investigate any possible changes resulting from a 4-month program of strenuous training and daily supplementation with soy protein at a level of 1 g/kg body weight. Gymnasts wtare randomly assigned to one of two groups seven to the Supplemented Group (A) and seven to the Non-Supplemented Group (B). Both groups took part in the same program, which consisted of strenuous training for 4-6 hours/day (except on Sunday, controlled food intake and supplements including vitamins and minerals. Group A received a supplement of Sports Beverage Protein Mix with SUPRO Isolated Soy Protein (ISP) twice daily. Group B received a placebo identical in appearance and flavour. Selected parameters were measured before and after the 4-month training program (lean body mass, fat mass, serum hemoglobin, protein, fats, urea and creatinine, liver enzymes, serum total calcium and magnesium, immunoglobulins, urinary mucoproteins, serum T3 and T4, estradiol, progesterone, prolactin, testosterone and urinary 17-ketosteroids). RESULTS: Results demonstrated that the Supplemented Group (A) had an increase in lean body mass and serum levels of prolactin (p < 0.01) and T4 and a decrease in serum alkaline phosphetases (p < 0.01). The Non-Supplemented Group (B) had a decreased level of serum T4 and an increased level of urinary mucoproteins (p < 0.05). CONCLUSIONS: Our preliminary conclusions might suggest lower metabolic-hormonal stress in elite female gymnasts undergoing strenuous training and who received daily supplementation with isolated soy protein.     

Comparison of exertional indices following moderate training in collegiate athletes

BACKGROUND: To better understand the inflammatory response to two divergent training modalities: running and weight training. METHODS: Experimental design: prospective, repeat measures, observational study of subjects over the course of 8-10 weeks of training. Data analysis was consonant with this design and included a repeat measures ANOVA with multiple posthoc comparisons. The level of significance was set at 0.05. Setting: collegiate athletic training facilities. Patients: twenty-two subjects comprised the study group. These included both male and female collegiate athletes, ages 17-22 years of age with a mean height of 178.6 cm, a mean weight of 77.5 kg and a mean lean body mass of 67.2 kg. Exclusion criteria consisted of hemophilia or chronic conditions requiring anti-inflammatory medication. Interventions: training for runners (n=11) consisted of multiple 5-km runs throughout the course of a 60-75 minute workout. For a comparable time period, weight trainers participated in multiple joint, total body strengthening workouts. Measures: four exertional indices were examined. These included serum levels of creatine kinase, lactate, Interleukin-6, and C-reactive protein. Assessments of these markers were made immediately before and after each training session. Three sessions were monitored over an 8-10 week period. RESULTS: The data show that moderate exertion is accompanied by modest increases in these markers. Mean serum values did not exceed 125 U/L for serum creatine kinase, 5 mM/I for lactates, and 2.6 pg/ml for IL-6. C-reactive protein was sporadically detectable in weight lifters only. These increases were detected immediately postexercise. Each training modality produced a unique profile for creatine kinase and IL-6, suggestive of a training effect. CONCLUSIONS: Overall, the levels for all exertional markers reported herein are well below those reported for exhaustive exercise. As consistent exhaustive efforts can catalyze overtraining syndromes, periodic assessments of these exertional indices could help to document the appropriateness of the training stimulus.     

Effects of a 15-d race on plasma steroid levels and leg muscle fitness in runners

Effects of increased training distance on resting plasma testosterone and adrenal steroid levels, serum markers of protein catabolism and muscle fiber damage, and field tests of leg muscle fitness were studied in 19 male marathon runners. Data were collected 1-2 d before and 1 d after a 400-km road race over 15 d. The runners maintained their usual training speeds even though the race distance was twice their regular mileage. Testosterone levels decreased 31% (P less than 0.01), from 23.5 +/- 1.7 to 16.2 +/- 1.0 nmol.l-1. The ratio of cortisol to testosterone increased 83% (P less than 0.01). Blood urea nitrogen (BUN) concentration increased from 16.7 +/- 0.7 to 21.8 +/- 1.0 mg.dl-1 (P less than 0.05) and serum total protein decreased from 7.09 +/- 0.10 to 6.88 +/- 0.08 g.dl-1 (P less than 0.05). Serum creatine kinase (CK) activity increased 380%, from 152 +/- 11 to 731 +/- 74 U.l-1 (P less than 0.001) and was associated with persistent leg muscle soreness. There were no significant changes in body weight, estimated lean body weight, hematocrit, or plasma cortisol, aldosterone, progesterone, androstenedione, and DHEA sulfate levels. Test scores for leg power (vertical jump), strength (dead lift), flexibility (sit-and-reach), and speed (timed stands) did not change significantly. The decrease in plasma testosterone did not correlate with the changes in either BUN, total protein, or CK. The results indicate that existent leg muscle fitness was unaltered despite the suppression of circulating testosterone and the development of early protein catabolism and muscular damage.     

Dietary supplements and the promotion of muscle growth with resistance exercise

Nutritional strategies of overfeeding, ingesting carbohydrate/protein before and after exercise, and dietary supplementation of various nutrients [e.g. protein, glutamine, branched-chain amino acid, creatine, leucine, beta-hydroxy beta-methyl-butyrate (beta-HMB), chromium, vanadyl sulfate, boron, prasterone (dehydroepiandrosterone [DHEA]) and androstenedione] have been purported to promote gains in fat-free mass during resistance training. Most studies indicate that chromium, vanadyl sulfate and boron supplementation do not affect muscle growth. However, there is evidence that ingesting carbohydrate/protein prior to exercise may reduce catabolism during exercise and that ingesting carbohydrate/protein following resistance-exercise may promote a more anabolic hormonal profile. Furthermore, glutamine, creatine, leucine, and calcium beta-HMB may affect protein synthesis. Creatine and calcium beta-HMB supplementation during resistance training have been reported to increase fat-free mass in athletic and nonathletic populations. Prasterone supplementation has been reported to increase testosterone and fat-free mass in nontrained populations. However, results are equivocal, studies have yet to be conducted on athletes, and prasterone is considered a banned substance by some athletic organisations. This paper discusses rationale and effectiveness of these nutritional strategies in promoting lean tissue accretion during resistance training.     

Short-term creatine supplementation does not alter the hormonal response to resistance training

PURPOSE: In this study, the effect of short-term creatine supplementation on the growth hormone, testosterone, and cortisol response to heavy resistance training was investigated. METHODS: According to a double-blind crossover study design, 11 healthy young male volunteers underwent a 1-h standardized heavy resistance training session (3 series of 10RM; 12 exercises), both before (pretest) and after (posttest) 5 d of either placebo (P, maltodextrine) or creatine (CR; 20 g.d-1, 5 d) supplementation. A 5-wk washout period separated the treatments. Thirty minutes before each training session, CR subjects ingested 10 g of creatine monohydrate (CR) while P subjects received placebo. Venous blood was sampled before, immediately after, and 30 and 60 min after the training session. RESULTS: The exercise-induced increase (P < 0.05) of serum growth hormone was not altered by acute creatine intake and was similar in P and CR. The weight training session, either or not in conjunction with acute or chronic creatine intake, did not significantly impact on serum testosterone. However, serum cortisol during recovery tended to be higher in CR than in P. CONCLUSION: It is concluded that short-term creatine supplementation does not alter the responses of growth hormone, testosterone, and cortisol to a single bout of heavy resistance training.     

Testosterone, cortisol, and creatine kinase levels in male distance runners during reduced training

The purpose of this study was to examine if reduced training would reestablish normal testosterone, cortisol, and creatine kinase (CK) levels in male distance runners. Ten male runners (mean +/- SE) age 32.0 +/- 2.6 yrs, body fat 9.6 +/- 1.0%, VO2max 61.8 +/- 1.1 ml/kg/min) were monitored during 4 weeks of normal training (baseline training, BT) and 3 weeks of reduced training (RT). During BT running distance averaged 81 +/- 5 km/week, 6 days/week. During RT the runners reduced weekly training volume by 70% of BT to 24 +/- 2 km/week and training frequency to 5 days/week. Weekly resting blood samples were obtained between 0600-0900 hrs after an overnight fast. During BT resting total testosterone levels averaged 5.10 +/- 0.21 ng/ml, which is within the low ranges previously reported in male distance runners. Testosterone levels were not affected by RT (avg of 5.38 +/- 0.31 ng/ml). Cortisol levels were in the high range of normal during BT (23.61 +/- 1.18 ug/dl) and were not altered with RT (avg of 23.14 +/- 1.56 ug/dl). Creatine kinase was elevated (168 +/- 15 U/L) during BT and was significantly reduced (P less than 0.001) at weeks 1-3 of RT (avg of 99 +/- 9 U/L). These results suggest that normally training male runners have low resting total testosterone levels and cortisol levels in the high-normal range. Resting testosterone and cortisol were not responsive to the training reduction. Creatine kinase appears to be sensitive to relative changes in training.     

Anabolic and catabolic hormonal response of elite runners to training at high altitude

A 2-week training period 2000 meters above sea level performed by 6 male elite Swedish runners influenced neither basal anabolic (total and non-sex hormone-binding globulin (SHBG)-bound testosterone (NST) and insulin-like growth factor-1 (IGF-1) nor catabolic (cortisol) hormones when comparing serum levels prior to and after the training camp. The anabolic vs catabolic hormone balance, expressed as the NST: cortisol ratio, also remained unchanged as well as SHBG and body mass. Thus, training at 2000 meters above sea level, often practised by elite runners to improve performance in competition at sea level, does not result in a catabolic situation after return to sea level, as measured by peripheral hormones. However, the adaptation to high altitude was associated with a slight (NS) decrease in testosterone as well as in anabolic vs catabolic balance as measured the third day at high altitude. Simultaneously, a decrease in subjective performance was claimed by the runners, but could not be shown by objective measurements. From day 3 to day 9 at high altitude, all runners claimed a subjective recuperation of performance. Total and non-SHBG-bound testosterone increased significantly from day 3 at high altitude to the first post-camp sea-level test. The results reflect the necessity of adaptation when travelling to races at different altitudes. The Swedish runners had significantly higher cortisol, total testosterone and NST levels compared with basal values of a group of 17 elite Kenyan runners living and training at high altitude. Since the NST cortisol and IGF-1 values were not lower, a catabolic state or malnutrition was not likely to be present. The results might reflect an adaptation to altitude or ethnic variations.     

Regional body composition determined by dual-energy x-ray absorptiometry. Relation to Training, Sex Hormones, and serum lipids in male long-distance runners

This study investigated the regional distribution of fatty and lean tissue in long-distance runners, and the relation to training, sex hormones, and serum lipids. One hundred and twenty lean men (22 elite, 86 recreational runners and 12 non-running controls) aged 32±8.1 years (mean±SD) participated. Body composition (adipose and lean tissue) was measured by dual-energy x-ray absorptiometry in the total body and in the abdomen, the arms and the legs. Regional and total body fat correlated inversely with the performance at an incremental treadmill exercise test (−0.61相似文献   

Effects of whey isolate, creatine, and resistance training on muscle hypertrophy

PURPOSE: Studies that have attributed gains in lean body mass to dietary supplementation during resistance exercise (RE) training have not reported these changes alongside adaptations at the cellular and subcellular levels. Therefore, the purpose of this study was to examine the effects of two popular supplements--whey protein (WP) and creatine monohydrate (CrM) (both separately and in combination)--on body composition, muscle strength, fiber-specific hypertrophy (i.e., type I, IIa, IIx), and contractile protein accrual during RE training. METHODS: In a double-blind randomized protocol, resistance-trained males were matched for strength and placed into one of four groups: creatine/carbohydrate (CrCHO), creatine/whey protein (CrWP), WP only, or carbohydrate only (CHO) (1.5 g x kg(-1) body weight per day). All assessments were completed the week before and after an 11-wk structured, supervised RE program. Assessments included strength (1RM, three exercises), body composition (DEXA), and vastus lateralis muscle biopsies for determination of muscle fiber type (I, IIa, IIx), cross-sectional area (CSA), contractile protein, and creatine (Cr) content. RESULTS: Supplementation with CrCHO, WP, and CrWP resulted in significantly greater (P < 0.05) 1RM strength improvements (three of three assessments) and muscle hypertrophy compared with CHO. Up to 76% of the strength improvements in the squat could be attributed to hypertrophy of muscle involved in this exercise. However, the hypertrophy responses within these groups varied at the three levels assessed (i.e., changes in lean mass, fiber-specific hypertrophy, and contractile protein content). CONCLUSIONS: Although WP and/or CrM seem to promote greater strength gains and muscle morphology during RE training, the hypertrophy responses within the groups varied. These differences in skeletal muscle morphology may have important implications for various populations and, therefore, warrant further investigation.