有氧运动对大鼠中枢神经系统HSP70表达的影响

目的:探讨有氧运动对大鼠中枢神经系统(CNS)细胞热休克蛋白70(HSP70)表达的影响.方法:40只SD大鼠分成5组,分别为对照组、中等强度耐力训练组、中等强度耐力训练 大强度力竭运动组、大强度耐力训练组和大强度耐力训练 大强度力竭运动组,耐力训练持续6周,力竭运动在最后1次耐力训练后次日进行,各组取材后采用免疫组化和图像分析方法观察运动对CNS脑和脊髓6个部位HSP70表达的影响.结果:中等、大强度耐力训练组CNS各部位HSP70表达水平与对照组相比显著增加;力竭运动组CNS各部位HSP70表达水平均高于相应的耐力训练组,其中中等强度耐力训练 大强度力竭运动组表达增加最显著.结论:耐力训练是CNS各部位HSP70表达水平增加的重要诱导因素,运动强度的适应性改变是决定耐力训练后CNS各部位HSP70表达量的主要因素.     

Relationships between leptin levels and carbohydrate intake during rowing training

AIM: This study was designed to determine the relationship between diet and leptin levels during rowing training. METHODS: Dietary intakes using 3-day food records, training volume and leptin responses to a 90-min exercise (measurement before, at the end and after 2 and 24 h of recovery) were assessed at the beginning and at the end of an 8-month training season for heavyweight rowers. RESULTS: During the training, we observed increases in energy intake and in training volume (12.1+/-1.8 and 14+/-1.4 MJ/day, and 3.8+/-1.1 and 6.5+/-1.8 sessions/week, respectively at the beginning and at the end of the season). Carbohydrate (CHO) and protein intakes were increased (P<0.001 and P<0.05, respectively), whereas those of lipid were unchanged (P=0.08). Leptin levels at rest were unchanged, while delayed decreases occurred (at 2 h postexercise) in response to the 90-min exercise (P<0.01). At the end of the season, postexercise and 24 h postexercise leptin levels were positively correlated to CHO intake (r=0.62 and r=0.69, respectively; P<0.05). CONCLUSION: There is an increase in CHO intake over a training season for rowers. Our results suggested that repeated hypoleptinemia in response to acute exercise triggered the particular choice of CHO in order to insure the energy homeostasis.     

Factors influencing the variations of ejection fraction during exercise in chronic aortic regurgitation

The influence of left ventricular volume variations and regurgitant fraction variations upon left ventricular ejection fraction during exercise was examined using equilibrium radionuclide angiography in patients suffering from aortic regurgitation. Ejection fraction (EF), regurgitant fraction (RF), end diastolic volume (EDV) and end systolic volume (ESV) variations from rest to peak exercise were determined in 44 patients suffering from chronic aortic regurgitation (AR) and in 8 healthy volunteers (C). In C, EF increased (+0.10 +/- 0.03, P less than 0.01) and ESV decreased significantly (-23% +/- 12%, P less than 0.01), RF and EDV did not vary significantly. In AR patients, EF, EDV and ESV did not vary significantly because of important scattering of individual values. Changes in EF and ESV were inversely correlated (r = -0.79, P less than 0.01) and RF decreased significantly (-0.12 +/- 0.10, P less than 0.01). Volumes and EF changes during exercise occurred in three different ways. In a 1st subgroup of 7 patients, EF increased (+0.09 +/- 0.03, P less than 0.05) in conjunction with a reduction of ESV (-24% +/- 12%, P less than 0.05) without a significant change in EDV. In a 2nd group of 22 patients, EF decreased (-0.04 +/- 0.07, P less than 0.01) in association with an increase in ESV (+17% +/- 16%, P less than 0.01) and no change in EDV. In a 2nd group of 22 patients, EF decreased (-0.04 +/- 0.07, P less than 0.01) in association with an increase in ESV (+17% +/- 16%, P less than 0.01) and no change in EDV. In a 3rd subgroup of 15 patients, EF decreased (-0.02 +/- 0.06, P less than 0.01) despite a reduction in ESV (-7% +/- 6%, P less than 0.01) because of a dramatic EDV decrease (-10% +/- 6%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Physiological and performance effects of low- versus mixed-intensity rowing training

PURPOSE: To examine the impact of low-intensity and a mixture of low- and high-intensity training on physiological and performance responses in rowing. METHODS: Eighteen experienced rowers undertook a 12-wk program of 100% < or = lactate threshold (LT) training (LOW) or 70% training at < or = LT and 30% at halfway (50%Delta) between the V O2 at LT and V O2peak (MIX). Responses were assessed before and after training by a progressive exercise test to exhaustion; multiple "square-wave" rest-to-exercise transitions of 6-min duration at 50%Delta; and a maximal 2000-m ergometer time trial. RESULTS: Improvements (P < 0.001) in 2000-m ergometer performance and V O2peak occurred independently of groups (P = 0.8 and 0.42, respectively). LOW improved the power at LT (23.5 +/- 12.2 vs 5.1 +/- 5.0 W, P = 0.013) and power at a [blood lactate] of 4 mM (32.3 +/- 6.9 vs 13.1 +/- 3.7 W, P = 0.03) compared with MIX. The time constant and gain of the primary component were unchanged with training, whereas the gain of the V O2 slow component was reduced with training, but independently of group. CONCLUSIONS: Both LOW and MIX training programs improved performance and V O2peak by the same magnitude, whereas LOW attenuated the blood lactate response to a given exercise intensity more so than MIX.     

Rate and amplitude of adaptation to intermittent and continuous exercise in older men

PURPOSE: This study determined the amplitude and rate of adaptation to 10 wk of continuous (CEx) and intermittent exercise (IEx) in a group of older men when the training intensity and total amount of work completed by each exercise group were the same. METHODS: Ten healthy men were assigned to either a CEx (63 +/- 1 yr) or IEx (65 +/- 1 yr) group while a further five subjects (65 +/- 1 yr) acted as nonexercising controls (CON). The three groups (CEx, IEx, and CON) were matched for age, peak oxygen uptake (VO2peak), and cardiac output (Qpeak) before commencing training. The CEx group trained for 30 min at an intensity corresponding to 70-75% VO2peak, and the IEx group trained for a total exercise time of 30 min using intermittent exercise (60-s exercise, 60-s rest) at the same absolute intensity as the CEx group (CEx 112 +/- 5W; IEx 112 +/- 5W). The exercise groups trained three times per week and completed a similar amount of work during each training session (CEx, 199 +/- 9 kJ; IEx 195 +/- 9 kJ, P = 0.67). RESULTS: The CEx and IEx groups had similar and significant amplitude increases in peak VO2, ventilation (VEpeak), power, Q, and SV after training. Peak VO2, Qpeak, SVpeak, and peak arteriovenous O2 difference for the CON group were unchanged. The change in VO2peak, peak ventilation, and peak power for CEx and IEx groups were best described by a linear model. Moreover, the CEx and IEx groups had the same rate of change in VO2peak (CEx: 0.02 +/- 0.00 L x min(-1) x wk(-1), IEx: 0.02 +/- 0.00 L x min(-1) x wk(-1), P = 0.32), VEpeak (CEx: 2.0 +/- 0.2 L x min(-1) x wk(-1), IEx: 1.2 +/- 0.5 L x min(-1) x wk(-1), P = 0.10), and peak power (CEx: 2.6 +/- 0.4 W x wk(-1), IEx: 2.6 +/- 0.4 W x wk(-1), P = 0.92). CONCLUSION: These results suggest that the amplitude and rate of change of select adaptations in men aged 60-70 yr are independent of the mode of training (i.e., continuous or intermittent exercise) when the absolute training intensity and the total amount of work completed were similar.     

Ventilatory responses and entrainment of breathing during rowing

The purpose of this investigation was to investigate the hypothesis that respiration was coupled with the mechanics of the rowing stroke. In the first part of the study, physiologic responses during incremental exercise on the variable-resistance rowing ergometer were compared in 16 untrained female subjects (U), 17 collegiate female rowers (C), and 21 elite oarswomen (E). Minute ventilation (VE) and frequency of respiration (fR) were examined on a log scale as their relationship with oxygen consumption (VO2) was exponential. The slopes for log VE/VO2 were similar for collegiate (0.65 +/- 0.02) and elite (0.59 +/- 0.01) rowers, but the slope was significantly higher for the untrained (0.87 +/- 0.01) subjects (P less than 0.001). Elite rowers utilized a higher tidal volume (VT) response per VO2 (0.68 +/- 0.04 vs 0.30 +/- 0.05; P = 0.01) and lower log fR response per VO2 (0.27 +/- 0.02 vs 0.50 +/- 0.03; P = 0.01) compared with collegiate rowers. The ratio of fR/strokes per minute (SPM) averaged 1.5 in E athletes but varied in the U and C groups. In the second part of the study, pattern and timing of respiration were recording using an inspiratory pneumotachygraph, analyzed, and compared with specific phases of the rowing stroke in ten untrained subjects and nine elite rowers. The ratio of inspiratory time (T1)/total respiratory time (TTOT) decreased during the drive phase and increased during the recovery phase in both untrained subjects and elite rowers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spine bone mineral density increases in experienced but not novice collegiate female rowers

PURPOSE: There is evidence that rowing exercise targets the spine, but the dose of exercise required to build bone is poorly understood. To further explore this topic, we studied the bone response at the spine in novice and experienced female collegiate rowers over their 6-month competitive season. We hypothesized that, with rowing strokes similar between groups during training, experienced rowers would produce greater force at the spine than novices and thus, gain more bone mineral density (BMD). METHODS: Subjects included 16 experienced rowers (21.2 +/- 1.2 yr) who had been rowing 26 +/- 10 months and 19 novice rowers (19.5 +/- 0.8 yr) who had been rowing three months and 14 controls (19.2 +/- 1.6 yr). BMD was assessed by DXA at baseline and after the 6-month competitive season. During the season, all rowers participated in the same training program and took approximately the same number of strokes per training session (1000-1200 repetitions). On the 2000- and 6000-m rowing ergometer tests experienced rowers had faster times, indicating that their power output, and thus force production, was greater than novices. RESULTS: In ANCOVA, adjusting for body mass index, age, and initial BMD, the experienced rowers demonstrated a 2.5% increase at the spine that was significantly different than that of the novice rowers, but BMD change scores in the rowing groups were not different than controls. CONCLUSION: Because the number of strokes (repetitions) was similar between rowing groups during training, the higher power output in experienced rowers produced higher forces at the spine over the 6-month period that resulted in gains in spine BMD. These results support the theory that force magnitude is a key variable in osteogenesis.     

Laboratory blood lactate profile is suited to on water training monitoring in highly trained rowers

AIM: This study validated the laboratory testing used to monitor on water training. The purpose was to test that reference heart rates (HR) determined during an incremental test elicit comparable blood lactate levels ([La](b)) during a 30 min on water rowing. METHODS: Blood lactate profile were determined during incremental graded exercise in 14 national and international level oarsmen. The HR corresponding to [La](b) of 2 and 3 mmol x l(-1) were determined (HRLa2 and HRLa3 respectively). The rowers then performed a 30 min training session in a boat. Training intensity, as assessed by HR monitors, had to range between HRLa2 and HRLa3. Field [La](b) (Laf) and HR (HRf) were measured at the end of the training session. RESULTS: Laf was 2.13+/-0.49 mmol x l(-1) (range: 1.43-3.07) and did not differ significantly from 2 mmol x l(-1). HRf (162+/-7.4 beats x min(-1)) ranged from HRLa2 (159+/-9.5 beats x min(-1)) to HRLa3 (171+/-9 beats x min(-1)). HRf was not significantly different from HRLa2. CONCLUSIONS: It was concluded that the HR determined during the laboratory testing are valid for monitoring on water training in highly trained rowers.     

Effects of short- and long-term detraining on the metabolic response to endurance exercise

Changes in the metabolic response to an endurance exercise were studied (18 rowing km at 75 % of maximal aerobic velocity) during detraining in ten rowers previously highly-trained. Maximal aerobic velocity (VO2 max) and the metabolic response to exercise were determined in the 1 st, 24 th, and 47 th week (training), and in the 52 nd, 76 th, and 99 th week (detraining). Over the decrease of VO2 max, detraining induced a biphasic alteration of the previously observed training adaptations: 1-short-term detraining (5 weeks) resulted in a lower adipose tissue triglyceride (TG) delivery during exercise (p = 0.029), but this one did not represent a direct metabolic limit to exercise since the liver TG delivery increased (p = 0.039), allowing that total fatty acid concentration remained unchanged (12.1 +/- 2.4 vs. 11.8 +/- 2.1 mmol/l; weeks 47 vs. 52); 2-long-term detraining (52 weeks) altered even more the metabolic response to exercise with a decreased total fatty acid concentration during exercise (week 99: 10.6 +/- 2.0 mmol/l; p = 0.022), which induced a higher glycolysis utilization. At this moment, a hemolytic response to endurance exercise was observed through haptoglobin and transferrin concentration changes (weeks 47 vs. 99; p = 0.029 and 0.027, respectively), which resulted probably from higher red blood cell destruction. Endurance-trained athletes should avoid detraining periods over a few weeks since alterations of the metabolic adaptations to training may become rapidly chronic after such delays.     

Inspiratory muscle training improves rowing performance

PURPOSE: To investigate the effects of a period of resistive inspiratory muscle training (IMT) upon rowing performance. METHODS: Performance was appraised in 14 female competitive rowers at the commencement and after 11 wk of inspiratory muscle training on a rowing ergometer by using a 6-min all-out effort and a 5000-m trial. IMT consisted of 30 inspiratory efforts twice daily. Each effort required the subject to inspire against a resistance equivalent to 50% peak inspiratory mouth pressure (PImax) by using an inspiratory muscle training device. Seven of the rowers, who formed the placebo group, used the same device but performed 60 breaths once daily with an inspiratory resistance equivalent to 15% PImax. RESULTS: The inspiratory muscle strength of the training group increased by 44 +/- 25 cm H2O (45.3 +/- 29.7%) compared with only 6 +/- 11 cm H2O (5.3 +/- 9.8%) of the placebo group (P < 0.05 within and between groups). The distance covered in the 6-min all-out effort increased by 3.5 +/- 1.2% in the training group compared with 1.6 +/- 1.0% in the placebo group (P < 0.05). The time in the 5000-m trial decreased by 36 +/- 9 s (3.1 +/- 0.8%) in the training group compared with only 11 +/- 8 s (0.9 +/- 0.6%) in the placebo group (P < 0.05). Furthermore, the resistance of the training group to inspiratory muscle fatigue after the 6-min all-out effort was improved from an 11.2 +/- 4.3% deficit in PImax to only 3.0 +/- 1.6% (P < 0.05) pre- and post-intervention, respectively. CONCLUSIONS: IMT improves rowing performance on the 6-min all-out effort and the 5000-m trial.     

A comparative study of left ventricular structure and function in elite athletes.

Adaptations to left ventricular (LV) structure and function appear to be dependent on the type, intensity and duration of exercise training. We therefore studied two clearly defined groups of elite athletes, by M-mode and Doppler echocardiography, with a group of inactive individuals as controls. All groups were age matched. Group 1 comprised ten elite endurance athletes with maximal oxygen consumption (VO2 max) of 74.7 +/- 1.43 (mean +/- SEM). Group 2 consisted of ten elite weightlifters with VO2 max 45.3 +/- 2.00. Group 3 comprised of ten inactive individuals with VO2 max 44.5 +/- 2.13. Left ventricular end diastolic dimension was significantly higher in group 1 (5.72 +/- 0.07) than in groups 2 or 3 (5.29 +/- 0.09 and 5.19 +/- 0.09 respectively, p less than 0.001). Left ventricular mass index was significantly higher in groups 1 and 2 (156.4 +/- 5.97 and 138.6 +/- 7.27 respectively) than in group 3 (104.1 +/- 3.16 p less than 0.001). Percentage fractional shortening was used as an index of systolic function and no significant difference was found between groups. Doppler E:A ratio was taken as an index of diastolic function and was found to be significantly elevated in group 1 at rest (3.37 +/- 0.24) compared with 2.38 +/- 0.16 and 1.99 +/- 0.10 in groups 2 and 3 respectively (p less than 0.003). On exercise, the E:A ratio in group 1 was significantly higher than in group 3 (1.95 +/- 0.14 and 1.23 +/- 0.05 respectively p less than 0.001), and tended to be higher than group 2 (1.68 +/- 0.15 p = ns). These data show that both modes of intense training produce left ventricular hypertrophy. Diastolic function is not impaired in the athletes and may be augmented in the endurance athletes.     

Weight lifting training and left ventricular function in adolescent subjects

AIM: Training during adolescence may influence the myocardium's adaptation. Effects of exercise training on left ventricular function differ depending whether they result from pressure or volume overload. Accordingly, the present study was designed to examine, by echocardiography studies, the effects of endurance versus weight lifting training modes on left ventricular contractility in healthy adolescent boys. METHODS: Sixty healthy adolescent boys were randomly and evenly divided into 3 groups: weightlifting training, run-training, and control. Exercising groups underwent 28-week training programs, 3-4 times a week, 35 min each session. The weight lifting program for consisted of training on 6 dynamic resistive machines at resistance corresponding to 6-repetition maximum. The running program was composed of aerobic exercise training at 65% of their VO(2max). RESULTS: At rest, only in the runners end diastolic volume and end systolic pressure-volume ratio differed significantly (P<0.05) from pre- to post-testing. During post-testing session at peak exercise, runners compared to weightlifters demonstrated improvement respectively in: wall stress (245+/-42 and 290+/-35 103 dyn.cm(2)), end systolic pressure-volume ratio (7.2+/-.7 and 6.4+/-.5 ratio) and ejection fraction (82+/-5% and 76+/-5%). Maximal oxygen uptake (48.2+/-3.2 and 43.8+/-3.5 mL.kg(-1).min(-1)), also improved significantly (P<0.05). Maximal load was significantly (P<0.05) higher in the runners and weight lifters than in the control group with significantly (P<0.05) higher values for the weight lifters than runners. CONCLUSION: This study has showed that in adolescent boys the mode of exercise training leads to significant differences in left ventricular function and contractility, related to differences in volume-after-load relationship and not to fundamental differences in the properties of the myocardium.     

Heart rate recovery from submaximal exercise in boys and girls

PURPOSE: To examine the changes in heart rate (HR) after two different submaximal exercise bouts in boys and girls. METHODS: Eleven boys (10.5 +/- 1.0 yr) and 10 girls (10.8 +/- 0.7 yr) participated in this study. Each child completed an initial graded exercise test to determine peak VO2. On subsequent and separate days, a 5-min submaximal exercise bout on a cycle ergometer was performed. One bout was conducted at 70 W, and the other bout corresponded to an intensity of 85-90% of peak VO2. VO2 and HR were measured during and after (1 min and 3 min). HR recovery responses from each submaximal exercise bout were analyzed using a group by time ANOVA, and Pearson-product correlations were determined between resting HR, peak VO2, and postexercise HR responses. RESULTS: HR in the boys was lower at the end of exercise and the first minute of recovery versus girls but not at the 3rd min of recovery. There were no differences in HR recovery after the relative exercise bout. Resting HR was significantly correlated with postexercise HR from both bouts (r = 0.52-0.69), whereas peak VO2 did not correlate to postexercise HR. ANCOVA using resting HR as the covariate eliminated the gender different noted with the recovery from the 70-W bout. CONCLUSIONS: In summary, postexercise HR responses differed between boys and girls when submaximal exercise was performed at an absolute work rate. When exercise was performed at a relative intensity, HR recovery responses were similar between the two groups. Resting HR appears to account for variations in postexercise HR better than peak VO2.     

Physiological changes following a 12 week gym based stair-climbing, elliptical trainer and treadmill running program in females

AIM: Despite the growing popularity in recent years of the elliptical trainer aerobic exercise modality the physiological changes induced following a training program using elliptical trainers remains unknown. The present study investigated the metabolic and cardiorespiratory improvements following a 12-week aerobic training program using elliptical trainer, treadmill or stair-climbing modalities. METHODS: Twenty-two moderately active females (28.6 +/- 5.3 y, 1.65 +/- 0.05 m) were randomly assigned to treadmill running (n=7), elliptical trainer (n=8) or stair-climber (n=7) groups and trained 3 days x week(-1) initially at 70-80% of maximum heart rate (HRmax) for 30 min, progressing to 80-90% HRmax for 40 min. Subjects performed incremental exercise to volitional exhaustion using an electronically loaded cycle ergometer before and upon completion of the program. In addition, subjects performed sub-maximal fixed load tests at 0, 4, 8 and 12 weeks, using ergometers specific to their exercise group. RESULTS: No significant inter-group differences were recorded for pre-training VO2max or VEmax. Significant (p<0.05) post-training increases in cycling VO2max and VEmax were observed for treadmill (mean +/- SEM, 40.7 +/- 2.2 vs 43.4 +/- 2.6 ml x kg(-1) x min(-1) and 82.9 +/- 5.1 vs 90.2 +/- 6.4 l x min(-1)), elliptical trainer (36.9 +/- 2.5 vs 39.6 +/- 2.4 ml x kg(-1) x min(-1) and 86.8 +/- 2.3 vs 92.5 +/- 4.1 l x min(-1)) and stair-climber (37.4 +/- 2.9 vs 39.2 +/- 3.1 ml x kg(-1) x min(-1) and 95.9 +/- 5.8 vs 97.4 +/- 5.8 l x min(-1)) modalities, however, the increases were not significantly different between groups. For all groups, sub-maximal HR significantly decreased from week 0 to 4, and from week 4 to 8. CONCLUSION: In moderately active females similar physiological improvements were observed using stair-climber, elliptical trainer and treadmill running when training volume and intensity were equivalent.     

Rate and amplitude of adaptation to two intensities of exercise in men aged 65-75 yr

PURPOSE: To test the hypothesis that in males aged 65-75 yr when the total amount of work completed is similar in endurance training three times per week for 12 wk at either 50% or 70% peak oxygen uptake (VO2(peak)), there will be no significant difference in time course and amplitude of selected responses. METHODS: Subjects were randomly assigned to three groups: 70% VO2(peak), N = 19; 50% VO2(peak), N = 16; or control group, N = 19. Subjects underwent a maximal cycle exercise test and blood volume (Evans Blue) determination at 0, 4, 8, and 12 wk. A submaximal exercise test (50 W) was conducted at weeks 0 and 12 where cardiac output was determined. The exercise groups maintained the same exercise relative intensity throughout the 12 wk and completed a similar total amount of work. RESULTS: There were significant and similar increases in peak VO2, power and heart rate (HR) for both exercise groups. Linear models best described the time course for peak power and HR in both exercise groups. In the 70% VO2(peak) group, a quadratic model for VO2 and a linear model for VE were the best fit. There were no significant changes in blood or plasma volume for any groups over the 12 wk. Significant increases in stroke volume and significant decreases in HR at 50 W were found in both exercise groups after training. CONCLUSION: Moderate-intensity cycle exercise (50% VO2(peak)) to achieve 180-200 kJ per session, three times a week for 12 wk is a safe and effective stimulus for healthy asymptomatic men aged 65-75 yr to improve functional capacity in a primarily linear manner.     

Seasonal variation of aerobic performance in soccer players according to positional role

AIM: The purpose of this study was to evaluate the seasonal variation in the cardiorespiratory fitness of soccer players according to positional role in the team. METHODS: Thirty-two male soccer players U-19 years old were studied, consisting of 10 central defenders (18.2+/-0.9 years and 8.5+/-1.6 years of training (Group A), 12 midfielders (18+/-1 years and 8.1+/-1.4 years of training (Group B) and 10 attackers (18.2+/-0.9 years and 8.4+/-1.5 years of training (Group C). All subjects underwent anthropometric measurements and maximal exercise tests on a treadmill four times during their annual training cycle and maximal blood lactate accumulation analysis in order to verify that maximal exertion was reached. The measurements took place in the beginning and at the end of the preparation period, in the middle as well as at the end of the competitive season. RESULTS: Group A showed increased VO2(max) (mL.kg(-1.)min(-1)) by 19.3% in the 2nd measurement, by 22.9% in the 3rd and by 17.6% in the 4th compared to the beginning, respectively (P 相似文献   

螺旋藻复方合剂对运动小鼠肝细胞、心肌和骨骼肌细胞超微结构及HSP70表达的影响

目的:研究螺旋藻复方对递增大负荷运动小鼠肝脏、心肌和骨骼肌的保护作用及对HSP70表达的影响.方法:用光学显微镜和电子显微镜分别观察递增大负荷运动和递增大负荷运动加螺旋藻复方对小鼠心肌、骨骼肌和肝组织的形态学影响.用免疫组化法(SP法)研究适量运动、递增大负荷运动、适量运动加螺旋藻复方和递增大负荷运动加螺旋藻复方对小鼠心肌细胞、骨骼肌细胞和肝细胞的HSP70蛋白表达的变化.结果:在光镜下,递增大负荷运动组小鼠心肌、骨骼肌和肝细胞出现了不同程度的水肿、变性和坏死,在电镜下,可见肌原纤维断裂、细胞肿胀、线粒体肿胀,空泡样变和细胞核核质溶解,可见凋亡小体.而递增大负荷运动加螺旋藻复方组小鼠心肌、骨骼肌和肝脏的病变程度明显减轻.运动各组小鼠心肌细胞、骨骼肌细胞和肝细胞HSP70表达均显著高于正常组(均P＜0.01),适量运动加螺旋藻复方组小鼠心肌细胞、骨骼肌细胞和肝细胞HSP70表达均高于适量运动组(P＜0.01或P＜0.05).递增大负荷运动加螺旋藻复方组小鼠心肌细胞、骨骼肌细胞和肝细胞HSP70表达均显著低于递增大负荷运动组(P＜0.01或P＜0.05),但与适量运动加螺旋藻复方组比较,无显著性差异(均P＞0.05).结论:螺旋藻复方能抵抗递增大负荷运动导致的组织细胞损伤,其分子机理可能与该方可提高运动诱导HSP70表达水平有关.     

Plasma leptin responses to prolonged sculling in female rowers

AIM: Plasma leptin concentrations are reduced in the presence of a negative energy balance. The purpose of this study was to investigate the effects of a prolonged single endurance rowing training session on plasma leptin concentrations in female rowers. METHODS: Ten female college level single scull rowers participa-ted in this study. Venous blood samples were obtained during the early follicular phase of the menstrual cycle immediately before and after on-water rowing lasting about 2 h (7518+/-293 s; distance covered 18.9+/-1.4 km; heart rate 150+/-7 beats. min(-1)). RESULTS: Blood lactate concentration did not change significantly during sculling training session (from 1.6+/-0.4 to 1.9+/-0.5 mmol. L(-1)) indicating that training was performed at moderate intensities. Leptin values were significantly reduced immediately after prolonged rowing by a mean 44% and no further changes occurred during the first 2 h of recovery. Insulin and glucose values were also decreased immediately after prolonged rowing. A further reduction in insulin was seen during the 2(nd) hour of recovery. No further changes occurred during the first 2 h of recovery in glucose concentration. Plasma leptin concentrations immediately after (r=-0.64), and 30 min (r=-0.66) and 2 h (r=-0.64) after an endurance rowing training session were related (p<0.05) to the distance covered. No such relation was observed for other measured blood biochemical parameters. Leptin also correlated with insulin measured at different time points after endurance training (r>0.64; p<0.05). Regression analyses demonstrated a positive relationship between total body fat mass and plasma leptin (R(2)>0.70; p<0.001) regardless of sampling time in female rowers. CONCLUSION: Our findings indicate that a prolonged low-intensity rowing training session results in an energy deficit beyond the threshold that is necessary to reduce plasma leptin concentration without changing body fat mass in female rowers. It was suggested that plasma leptin could be regarded as a signal for metabolic reaction to endurance rowing training session and following recovery in female endurance athletes.     

利用低氧帐篷进行"高住低练"对划船运动员运动能力影响的初探

目的探讨"高住低练"(运动员睡在相当于2500m的高度,训练则在平原)与"低住低练"对划船运动员运动能力影响的差别.通过对20名划船运动员的对比研究,发现运动员在进行为期4周的高住低练过程中,实验组在实验第15天、第30天,红细胞数、红细胞压积及血红蛋白水平均明显高于实验前水平,对照组则在上述时间段无明显变化.HiLo组运动员4mmol/L乳酸无氧阈功率明显高于实验前,比实验前平均增长了31W,对照组仅增长了10.5W,与实验前相比无明显差异,实验组的增长值明显高于对照组.两组运动员的无氧作功能力无明显差异.实验组和对照组2000m成绩与实验前比较,均无显著性差异,但实验组的平均成绩提高幅度要大于对照组;5000m成绩两组与实验前比较都有明显提高,但是实验组出现十分显著的提高,提高值显著高于对照组.以上结果表明,高住低练能明显提高运动员的有氧耐力和专项耐力成绩.