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1.
Abstract

The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon®), an oral booster immunomodulator, or placebo to 16 professional cyclists (n=8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.  相似文献   

2.
We tested the hypothesis that changes in serum cartilage oligomeric matrix protein (COMP), tumour necrosis factor α (TNF-α), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) concentration after regular endurance training and running a marathon race depend on body mass index (BMI) and/or on marathon performance. Blood samples were collected from 45 runners of varying BMI and running experience before and after a 10-week marathon training programme and before, immediately and 24 h after a marathon race. Serum biomarker concentrations, BMI and marathon finishing time were measured. The mean (95% confidence interval (CI)) changes from before to immediately after the marathon were COMP: 4.09 U/L (3.39–4.79 U/L); TNF-α: ?1.17 mg/L (?2.58 to 0.25 mg/L); IL-6: 12.0 pg/mL (11.4–12.5 pg/mL); and hsCRP: ?0.08 pg/mL (?0.14 to ?0.3 pg/mL). The mean (95% CI) changes from immediately after to 24 h after the marathon were COMP: 0.35 U/L (?0.88 to 1.57 U/L); TNF-α: ?0.43 mg/L (?0.99 to 0.13 mg/L); IL-6: ?9.9 pg/mL (?10.5 to ?9.4 pg/mL); and hsCRP: 1.52 pg/mL (1.25–1.79 pg/mL). BMI did not affect changes in biomarker concentrations. Differences in marathon finishing time explained 32% of variability in changes in serum hsCRP and 28% of variability in changes in serum COMP during the 24 h recovery after the marathon race (P < 0.001). Slower marathon finishing time but not a higher BMI modulates increases in pro-inflammatory markers or cartilage markers following a marathon race.  相似文献   

3.
Abstract

The aim of this study was to determine whether the highest vitamin C supplementation associated with complete bioavailability influences the plasma and blood mononuclear cell IL-6 and IL-10 response to exercise. A double-blinded study of supplementation with vitamin C was performed. After 15 days of supplementation with vitamin C (500 mg · day?1, n = 16) or a placebo (n = 15), participants in the study completed a 15-km run competition. Blood samples were taken before and after competition. Oxidative stress markers, antioxidants, cortisol, IL-6 and IL-10 were determined in plasma or serum. IL-6 and IL-10 protein and mRNA levels were measured in blood mononuclear cells. Although higher plasma and blood mononuclear cell vitamin C levels were observed in the supplemented group when compared with the placebo one, the two groups showed identical exercise-induced changes in all the measured parameters. Exercise induced increased IL-6 and IL-10 levels in plasma and blood mononuclear cells. IL-6 and IL-10 mRNA levels in blood mononuclear cells increased after the competition. After recovery, IL-6 mRNA returned to basal levels and IL-10 mRNA levels remained elevated. In conclusion, exercise induced increased IL-6 and IL-10 production in blood mononuclear cells. However, vitamin C supplementation did not influence IL-6 and IL-10 response to exercise.  相似文献   

4.
金其贯  王海军  顾明 《体育与科学》2007,28(5):74-76,81
为了研究糖的补充对大负荷训练大鼠免疫功能的影响,通过对大鼠进行为期8周、每周6次,每次150min的游泳训练,建立运动性免疫抑制的模型,并补充糖,测定机体淋巴细胞的增殖功能、细胞因子等免疫指标的变化和淋巴细胞凋亡的变化。结果发现:8周的大负荷运动训练后,大鼠外周血液中淋巴细胞转化率、血清IL-2和GM-CSF含量均显著降低,而血清sIL-2R含量和淋巴细胞凋亡率显著增高。从而说明,大负荷的运动训练可能引起外周淋巴细胞凋亡增加,导致机体细胞免疫功能的降低。而在每次训练之前补充糖,可以使训练大鼠外周血液中淋巴细胞转化率、血清IL-2和GM-CSF含量均显著增高,淋巴细胞凋亡率显著降低。从而说明,糖的补充对大负荷训练引起的运动性免疫抑制具有重要的干预作用。  相似文献   

5.
We evaluated the effects of specific inspiratory muscle training on simulated time-trial performance in trained cyclists. Using a double-blind, placebo-controlled design, 16 male cyclists (VO 2max = 64 - 2 ml·kg -1 ·min -1 ; mean - sx ¥ ) were assigned at random to either an experimental (pressure-threshold inspiratory muscle training) or sham-training control (placebo) group. Pulmonary function, maximum dynamic inspiratory muscle function and the physiological and perceptual responses to maximal incremental cycling were assessed. Simulated time-trial performance (20 and 40 km) was quantified as the time to complete pre-set amounts of work. Pulmonary function was unchanged after the intervention, but dynamic inspiratory muscle function improved in the inspiratory muscle training group ( P h 0.05). After the intervention, the inspiratory muscle training group experienced a reduction in the perception of respiratory and peripheral effort (Borg CR10: 16 - 4% and 18 - 4% respectively; compared with placebo, P h 0.01) and completed the simulated 20 and 40 km time-trials faster than the placebo group [66 - 30 and 115 - 38 s (3.8 - 1.7% and 4.6 - 1.9%) faster respectively; P = 0.025 and 0.009]. These results support evidence that specific inspiratory muscle training attenuates the perceptual response to maximal incremental exercise. Furthermore, they provide evidence of performance enhancements in competitive cyclists after inspiratory muscle training.  相似文献   

6.
Strenuous physical exercise of the limb muscles commonly results in damage, especially when that exercise is intense, prolonged and includes eccentric contractions. Many factors contribute to exercise-induced muscle injury and the mechanism is likely to differ with the type of exercise. Competitive sports players are highly susceptible to this type of injury. AM3 is an orally administered immunomodulator that reduces the synthesis of proinflammatory cytokines and normalizes defective cellular immune fractions. The ability of AM3 to prevent chronic muscle injury following strenuous exercise characterized by eccentric muscle contraction was evaluated in a double-blind and randomized pilot study. Fourteen professional male volleyball players from the First Division of the Spanish Volleyball League volunteered to take part. The participants were randomized to receive either placebo (n=7) or AM3 (n=7). The physical characteristics (mean+/-s) of the placebo group were as follows: age 25.7+/-2.1 years, body mass 87.2+/-4.1 kg, height 1.89+/-0.07 m, maximal oxygen uptake 65.3+/-4.2 ml.kg(-1).min(-1). Those of the AM3 group were as follows: age 26.1+/-1.9 years, body mass 85.8+/-6.1 kg, height 1.91+/-0.07 m, maximal oxygen uptake 64.6+/-4.5 ml.kg(-1).min(-1). All participants were evaluated for biochemical indices of muscle damage, including concentrations of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatine kinase (CK) and its MB fraction (CK-MB), myoglobin, lactate dehydrogenase, urea, creatinine and gamma-glutamyltranspeptidase, both before and 30 days after treatment (over the peak of the competitive season). In the placebo group, competitive exercise (i.e. volleyball) was accompanied by significant increases in creatine kinase (494+/-51 to 560+/-53 IU.l(-1), P < 0.05) and myoglobin (76.8+/-2.9 to 83.9+/-3.1 microg.l(-1), P < 0.05); aspartate aminotransferase (30.8+/-3.0 to 31.1+/-2.9 IU.l(-1)) and lactate dehydrogenase (380+/-31 to 376+/-29 IU.l(-1)) were relatively unchanged after the 30 days maximum effort. AM3 not only inhibited these changes, it led to a decrease from baseline serum concentrations of creatine kinase (503+/-49 to 316+/-37 IU.l(-1), P < 0.05) and myoglobin (80.1+/-3.2 to 44.1+/-2.6 IU.l(-1), P < 0.05), as well as aspartate aminotransferase (31.1+/-3.3 to 26.1+/-2.7 IU.l(-1), P < 0.05) and lactate dehydrogenase (368+/-34 to 310+/-3 IU.l(-1), P < 0.05). The concentration of CK-MB was also significantly decreased from baseline with AM3 treatment (11.6+/-1.2 to 5.0+/-0.7 IU.l(-1), P < 0.05), but not with placebo (11.4+/-1.1 to 10.8+/-1.4 IU.l(-1)). In conclusion, the use of immunomodulators, such as AM3, by elite sportspersons during competition significantly reduces serum concentrations of proteins associated with muscle damage.  相似文献   

7.
Vertigo has been described after the practice of mountain bike. This study aimed to investigate the prevalence of vertigo following competitions or training sessions of downhill mountain biking (DMB) or road cycling (RC). One hundred and two DMB riders, 79 road cyclists and 73 control participants filled in a survey intended to evaluate the prevalence of vertigo in daily living activities and following competitions or training sessions. Vertigo causal factors (crashes, head trauma, fatigue, characteristics of the path/road ridden) were recorded. DMB riders and road cyclists did not report more vertigo during daily living activities than controls. But DMB riders older than 30 had more risk to report vertigo than age-matched road cyclists (OR: 5.06, 95% CI: 1.23–20.62). Road cyclists aged between 20 and 29 were 2.59-fold (95% CI: 1.06–6.27) more likely to report vertigo than controls. After competitions and training sessions, DMB riders were 2.33-fold (95% CI: 1.22–4.41) more likely to report vertigo than road cyclists. Vertigo causal factors were crash with head trauma in DMB riders and fatigue in road cyclists. Vertigo during daily living activities may be of concern for cyclists, particularly older DMB riders. The accumulation of impacts (crashes, vibrations) during the career of a DMB rider may generate micro-traumatisms of the central nervous system and/or peripheral vestibular structures, particularly the otolith organs. In RC, the pathophysiological mechanisms generating vertigo might be effort-related disturbance of homeostasis. To avoid injuries, DMB riders should be aware that vertigo may occur at the end of training sessions or competitions.  相似文献   

8.
研究目的：研究运动训练后采用低氧处理对肾组织低氧应激反应基因mRNA表达的影响。研究方法：将健康雄性SD大鼠32只，随机分为4组，采用基因芯片方法，检测肾组织中低氧应激反应基因mRNA表达。研究结果：低氧训练可改变大鼠肾组织中部分低氧应激基因的mRNA的丰度，其中，PDIPL mRNA、RHODANESE mRNA表达上调，AM mRNA、HSP40 mRNA、ECE1 mRNA、ENO-1 mRNA、IL-1B mRNA、IL-6 mRNA、TSG-14 mRNA袁达下调；低氧训练没有改变IL-1A mRNA、BMYB mRNA的丰度。肾组织中低氧应激基因mRNA在低氧训练的第3、6、13天呈现不同的变化，RHODANESE mRNA表达持续上升，而AM mRNA、HSP40 mRNA、ECE1 mRNA、ENO-1 mRNA、IL-1B mRNA、IL-6 mRNA、PDIPL mRNA、TSG-14 mRNA表达下调并于训练的第13天回到安静状态的表达水平。  相似文献   

9.
The psychobiological status of cyclists over a period of 8 months of training was assessed by measuring the sympatho-adrenal level, the central noradrenergic activity, and the cortisol-testosterone ratio status noninvasively. Alteration of these indices after a large increase in training load lasting 4 days (+ 187%) was also examined. Urinary excretion of methoxyamines (metanephrine, normetanephrine) and 3-methoxy-4-hydroxyphenylglycol sulphate (MHPG-S), and salivary concentrations of cortisol and testosterone, were measured in 12 national cyclists after a non-specific training period and 48 h before 4 days of increased training (T1), after these 4 days (T2) and at the end of 4 months of specific training (T3). Urinary and salivary samples were also collected during a rest period (T0). At each of these times, mood states and ratings of perceived muscle soreness were assessed, and a questionnaire of early clinical symptoms of the overtraining syndrome (Profile of Mood States) was administered. A significant increase in normetanephrine (P < 0.05) and a decrease in the testosterone-cortisol ratio (P < 0.05) were observed at T2, while MHPG-S excretion remained unchanged. Over the same periods, increased training loads did not induce mood disturbances. Eight months of training were associated with significant alterations in metanephrine (P < 0.05) and MHPG-S (P < 0.05). These results suggest a dissociation between the neural and endocrine catecholaminergic components systems. Opposite responses between MHPG-S and Profile of Mood States scores show that further investigations are needed to understand the relationship between central noradrenergic function, which is recognized as a regulatory factor of mood, and psychological tests measuring mood.  相似文献   

10.
Adverse effects of energy restriction on myogenic enzymes in judoists   总被引：1，自引：1，他引：0  
In this study, we examined the effects of weight reduction by restricting energy intake on muscle function and serum concentrations of myogenic enzymes in judoists. Twenty-seven male judoists aged 19.3 +/- 0.6 years (mean +/- s) were divided into three groups based on the extent of body weight reduction: high weight reduction (height 1.70 +/- 0.05 m, body mass 78.5 +/- 13.6 kg), low weight reduction (height 1.70 +/- 0.05 m, body mass 80.7 +/- 13.1 kg) and a group that maintained body weight while continuing to perform exercise training (height 1.78 +/- 0.07 m, body mass 78.7 +/- 8.8 kg). Body composition, blood biochemistry, energy intake and anaerobic power were assessed on four occasions: 20 days (baseline data), 4 days and 1 day before and 7 days after competition. Compared with baseline, body mass and fat-free mass were significantly lower 1 day before competition in the high and low weight reduction groups (both P < 0.01); these changes persisted for 7 days after competition in the high weight reduction group. Serum creatine kinase was significantly elevated 1 day before competition in all groups (all P < 0.05), and remained higher 7 days after competition in both the high and low weight reduction groups. Compared with baseline, maximal anaerobic power was significantly lower 1 day before competition only in the high weight reduction group (P < 0.01). Our results suggest that energy restriction in addition to intense exercise training before major competition has an adverse effect on anaerobic power and elevates serum creatine kinase concentration, leading to an impairment of muscular function and an increased susceptibility of muscle tissue to injury.  相似文献   

11.
目的：比较在赛前训练阶段采用加压训练结合SIT训练与单独SIT训练对公路自行车运动员运动能力的影响。方法：将12名云南省女子公路自行车运动员随机分为两组，在训练前后分别进行身体成分测试、递增负荷测试和Wingate无氧功测试。结果：（1）两组运动员训练前后体重、肌肉量无明显变化，加压组体脂率较训练前差异呈显著性（P＜0.05），对照组骨骼肌含量较训练前有显著差异（P＜0.05）；（2）训练后加压组最大摄氧量相对值、无氧阈心率 、最大心率与每搏输出量较训练前差异非常显著（P＜0.01），最大有氧输出功率较训练前差异呈显著性（P＜0.05），对照组各指标的变化趋势与加压组相似，但增长幅度较加压组小，无氧阈心率、最大心率较训练前差异呈显著性（P＜0.05），每搏输出量较训练前差异呈非常显著性（P＜0.01），两组运动员VE均较训练前有所下降；（3）训练后加压组峰值功率、相对峰值功率、平均功率、相对平均功率较训练前差异呈显著性（P＜0.05）；对照组峰值功率与相对峰值功率较训练前差异呈显著性（P＜0.05）；平均功率与相对平均功率较训练前稍有下降。结论：（1）赛前3周加压训练结合SIT训练和单纯SIT训练均可引起机体蛋白质分解代谢和降解加速，而导致骨骼肌含量下降；（2）赛前加压训练结合SIT训练和单纯SIT训练均可有效提高公路自行车运动员的有氧运动能力，且加压训练结合SIT训练较单纯SIT训练的增长幅度更明显，训练效果更佳；（3）赛前加压训练结合SIT训练可有效提升公路自行车运动员爆发力水平和无氧耐力水平。  相似文献   

12.
自行车场地全能赛是2012年伦敦奥运会自行车正式比赛项目,运动员在连续两天内需要完成6个小项的比赛。全能赛对运动员的专项速度和耐力素质水平均有较高要求,其中速度能力对比赛成绩的影响大于耐力,速度型运动员可能更加适合从事全能赛项目。全能赛对运动员专项能力的全面要求决定了训练的复杂性,应根据阶段训练目标和运动员的不足针对性的安排专项能力、身体力量和有氧能力训练。  相似文献   

13.
目的:观察世居高原自行车运动员在亚高原训练期间的机能变化.方法:以8名世居高原(海拔1910m)男子公路自行车运动员为研究对象,系统测试每名运动员在下亚高原前、亚高原(海拔1300m)训练第2天、第4天、第8天、第18天、第25天及第32天的红细胞(RBC)、红细胞压积(Hct)、血红蛋白(Hb)、血清睾酮(T)、皮质醇(C)、晨脉(HR)、脉搏血氧饱和度(SpO2)等血液生化指标及生理指标.结果:①世居高原运动员下到亚高原环境,大气氧分压增加了10mmHg,运动员Sp02上升了1％,晨脉下降了5次/分,均无统计学差异.②运动员RBC、Hct、Hb在亚高原训练的第2天开始下降,并在第4天降至最低,RBC下降明显(P＜0.01),较高原下降了9.25％,Hb稍有下降;一周后各血象指标逐渐回升,并在第25天时升至最高水平,Hb升高了4.33％,且差异显著(P＜0.05),RBC无变化.③运动员血清T在亚高原训练的前3周与高原相比无差异,3周后升高,并在第25天显著升高(P＜0.05),较高原升高15.56％;C在第二天较高,随后下降,T/C比值变化甚微.结论:世居高原男子自行车运动员亚高原训练期间第1周身体机能状况较差,随后逐渐恢复,在3周后达到最好水平.提示世居高原男子自行车运动员到亚高原比赛时的最佳时间为下至亚高原3周后.  相似文献   

14.
In this study, we examined the effects of weight reduction by restricting energy intake on muscle function and serum concentrations of myogenic enzymes in judoists. Twenty-seven male judoists aged 19.3±0.6 years (mean±s) were divided into three groups based on the extent of body weight reduction: high weight reduction (height 1.70±0.05?m, body mass 78.5 ±13.6?kg), low weight reduction (height 1.70±0.05?m, body mass 80.7±13.1?kg) and a group that maintained body weight while continuing to perform exercise training (height 1.78± 0.07?m, body mass 78.7±8.8?kg). Body composition, blood biochemistry, energy intake and anaerobic power were assessed on four occasions: 20 days (baseline data), 4 days and 1 day before and 7 days after competition. Compared with baseline, body mass and fat-free mass were significantly lower 1 day before competition in the high and low weight reduction groups (both P?<0.01); these changes persisted for 7 days after competition in the high weight reduction group. Serum creatine kinase was significantly elevated 1 day before competition in all groups (all P?<0.05), and remained higher 7 days after competition in both the high and low weight reduction groups. Compared with baseline, maximal anaerobic power was significantly lower 1 day before competition only in the high weight reduction group (P?<0.01). Our results suggest that energy restriction in addition to intense exercise training before major competition has an adverse effect on anaerobic power and elevates serum creatine kinase concentration, leading to an impairment of muscular function and an increased susceptibility of muscle tissue to injury.  相似文献   

15.
All traumatic and overuse injuries occurring during an average period of 4 years (2002/09) in a group of 51 currently active road top-level cyclists were retrospectively registered through clinical interviews. Average age was 25.8 years. Average training and competition period was 28.3 ± 2.4 h a week. Only 8 cyclists (15.6%) were completely free from lesions during the period of study. The remaining 43 cyclists suffered a total of 112 lesions; however, 9 out of these were unrelated to their cycling practice. These 103 cycling-related injuries include 50 (48.5%) traumatic and 53 (51.5%) overuse injuries. Twenty-eight fractures were reported, the clavicle being the most frequently affected bone (11 cases). The 68.5% of overuse injuries were located in the lower limbs. Most overuse injuries (89.6%) occurred during the training period. According to the injury abbreviated scale (AIS), severe lesions were only found in 4 cases (8% of traumatic injuries). Overall injury rates were 0.50 per racer/year, 2.02 per studied racer, and 0.007 per 1000 km of training and competition. Active professional top-level cyclists are exposed to a high injury risk. According to the scarce previously published data the current study provides relevant information on the injury occurrence of still active top-level road cycling.  相似文献   

16.
We evaluated the effects of specific inspiratory muscle training on simulated time-trial performance in trained cyclists. Using a double-blind, placebo-controlled design, 16 male cyclists (VO2max = 64 +/- 2 ml x kg(-1) x min(-1); mean +/- s(x)) were assigned at random to either an experimental (pressure-threshold inspiratory muscle training) or sham-training control (placebo) group. Pulmonary function, maximum dynamic inspiratory muscle function and the physiological and perceptual responses to maximal incremental cycling were assessed. Simulated time-trial performance (20 and 40 km) was quantified as the time to complete pre-set amounts of work. Pulmonary function was unchanged after the intervention, but dynamic inspiratory muscle function improved in the inspiratory muscle training group (P < or = 0.05). After the intervention, the inspiratory muscle training group experienced a reduction in the perception of respiratory and peripheral effort (Borg CR10: 16 +/- 4% and 18 +/- 4% respectively; compared with placebo, P < or = 0.01) and completed the simulated 20 and 40 km time-trials faster than the placebo group [66 +/- 30 and 115 +/- 38 s (3.8 +/- 1.7% and 4.6 +/- 1.9%) faster respectively; P = 0.025 and 0.009]. These results support evidence that specific inspiratory muscle training attenuates the perceptual response to maximal incremental exercise. Furthermore, they provide evidence of performance enhancements in competitive cyclists after inspiratory muscle training.  相似文献   

17.
Maximal strength, power, muscle cross-sectional area, maximal and submaximal cycling endurance characteristics and serum hormone concentrations of testosterone, free testosterone and cortisol were examined in three groups of men: weightlifters (n = 11), amateur road cyclists (n = 18) and age-matched controls (n = 12). Weightlifters showed 45-55% higher power values than road cyclists and controls, whereas the differences in maximal strength and muscle mass were only 15% and 20%, respectively. These differences were maintained when average power output was expressed relative to body mass or relative to muscle cross-sectional area. Road cyclists recorded 44% higher maximal workloads, whereas submaximal blood lactate concentration was 50-55% lower with increasing workload than in controls and weightlifters. In road cyclists, workloads associated with blood lactate concentrations of 2 and 4 mmol.l-1 were 50-60% higher and occurred at a higher percentage of maximal workload than in weightlifters or controls. Basal serum total testosterone and free testosterone concentrations were lower in elite amateur cyclists than in age-matched weightlifters or untrained individuals. Significant negative correlations were noted between the individual values of maximal workload, workloads at 2 and 4 mmol.l-1 and the individual values of muscle power output (r = -0.37 to -0.49), as well as the individual basal values of serum total testosterone and free testosterone (r = -0.39 to -0.41). These results indicate that the specific status of the participants with respect to training, resistance or endurance is important for the magnitude of the neuromuscular, physiological and performance differences observed between weightlifters and road cyclists. The results suggest that, in cycling, long-term endurance training may interfere more with the development of muscle power than with the development of maximal strength, probably mediated by long-term cycling-related impairment in anabolic hormonal status.  相似文献   

18.
Good sleep is critical for optimising recovery and athletic performance. Yet, few studies have investigated how athletes sleep before and during competition. The aim of this study was to determine whether such sleep is poorer than that before a usual training day. Twenty-one male endurance cyclists’ (age: 19.9 ± 1.7 years) sleep/wake behaviour was assessed using wrist activity monitors for 11 nights, including a six-night baseline training phase, three nights before competition and two nights during competition. Cyclists had less sleep on the night before competition (6.5 ± 0.9 h) and during the first night of competition (6.8 ± 0.8 h) than at baseline (7.4 ± 0.6 h). Cyclists also went to bed and woke up earlier during competition than at baseline. Competition schedules and competition itself can disrupt the sleep/wake behaviour of athletes during competition. Future investigations should examine sleep during three stages of competition (i.e. before, during and after competition). This will help coaches develop a greater understanding of how sleep changes during different phases of competition and enable them to plan post-competition training programmes to ensure appropriate rest and recovery is obtained.  相似文献   

19.
This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue.  相似文献   

20.
通过对上海市男子短距离自行车运动员在10运会前一年的比赛、训练情况进行连续追踪，应用SRM训练系统对运动员在训练和比赛情况进行分析，对SRM训练系统在自行车运动员专项力量训练中的应用进行了探讨，结果发现：（1）使用SRM训练系统可以监测自行车运动员比赛或训练中的实时情况，通过功率、速度以及频率等指标，可以反映自行车运动员专项能力的变化情况。（2）自行车运动员的运动成绩取决于专项力量的大小，而不是绝对力量的高低。（3）自行车运动员的专项力量是在自行车运动中表现出来的一种高频率的踏蹬力量。  相似文献   

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