运动负荷对青年学生和运动员心脏功能的影响

用无创法(阻抗法)测量了40名青年学生和40名运动员在两种运动负荷(50W和150W)运动前、运动后即刻和恢复时程的收缩时间间期(STI)和心率(HR)。在静态时,“运动员组”的心率较缓(P<0.01)、QS_1较长(P<0.05)、PEP/LVET比值较大(P<0.05和P<0.01)、LVETc较短(P<0.001)。运动后即刻,“学生组”和“运动员组”都表现为QS_z、LVET、PEP、IVCT、QS_1缩短、PEP/LVET比值减小、心率增速和LVETc延长。但“运动员组”QS_2、LYET的缩短和心率增速的程度较少,而PEP/LVET比值的减小和LVETc延长的程度较大。除PEP/LVET比值外,其余各项指标的恢复速度均与负荷量有关。“运动员组”的恢复速度较快,尤其在150W时更为明显。本文指出:1)用阻抗法测算动态下的STI更为实用;2)系统训练可提高心脏活动的潜力,改善泵功能,促进心脏活动的调节速度。     

Arrhythmogenic right ventricular dysplasia and sudden cardiac death in Croatians' young athletes in 25 years

The paper deals with the sudden cardiac death during training in male athletes in Croatia. The data are a part of a retrospective study dealing with 67 sudden death due to physical activity in men in Croatia during 25 years: from January 1, 1986 to December 31, 2010. Two of them suddenly died during training due to malignant ventricular arrhythmia because of the arrhythmogenic right ventricular dysplasia. First was a short trails runner aged 24, with no any previous physical discomforts, who suddenly collapsed and died during training. The second was a soccer player aged 13, with no any previous physical discomfort, who suddenly collapsed and died during training. A sudden cardiac death due to physical exercise in young athletes in Croatia suffered of arrhythmogenic right ventricular dysplasia reached 0.07/ 100.000 yearly (p = 0.00000), in all young athletes suffered of heart diseases reached 0.19/100 000 (p = 0.00005), and in the total male population aged 15-40 engaged in sports and recreational physical exercise: 0.71/100.0000 (p = 0.00001).     

The impact of exercise on thyroid hormone metabolism in children and adolescents.

Thyroid hormones are important regulators of energy metabolism and may influence energy processes during physical exercise. There are controversial results concerning thyroid hormone metabolism during strenuous exercise in adult athletes and only scant data concerning the impact of strenuous exercise on thyroid hormone metabolism in children and adolescents. Although some studies demonstrate a transient change in thyroid hormones during intense physical performance, most studies agree that these changes are of minor impact, practically reflecting the relative negative energy balance during strenuous exercise. This state of hypometabolism during intense physical performance has also been confirmed in highly trained female young athletes, who may be also characterized by reproductive axis dysfunction, manifested either as luteal-phase deficiency or amenorrhea, alongside the typical constellation of low T3, insulin and leptin levels. More importantly, strenuous exercise during childhood or adolescence is mostly accompanied by a delay of skeletal maturation, and height and may have a long-lasting negative effect on growth and acquisition of maximum bone mass. In conclusion, although thyroid hormones are only transiently or insignificantly changed during strenuous exercise, adequate caloric intake should be guaranteed in highly performing young athletes in order to counteract the relative negative energy balance and prevent alterations in endocrine-metabolic profile. Moreover, when growth and pubertal progression in very young athletes are significantly impaired, a reduction in the intensity of the physical exercise should be advocated in order to guarantee better final height and adequate acquisition of bone mass.     

运动员心功能评估新方法和新指标的研究

目的：探讨无创检测和评估心功能的新指标和新方法。方法：随机抽取81名体育系学生（买验组,n=81）和41名普通系学生（对照组,n=41）,完成规定运动量的台阶运动后,通过采集心音信号,进行了心率,D／S比值以及S1／S2比值的对照研究。结果：在静息状态下,体育系学生的心率为66．2±8．7,D／S比值为2．04±0．33;晋通系学生的心率为70．8±8．0,D／S比值为1．82±0．27;在全运动量下,体育系学生的S1／S2比值为7．34±4．04;普通系学生的S1／S2比值为5．22±2．38。,结论：体育系学生比普通系学生具有较高水平的心脏储备：该方法可用来评估运动员与一般人的心脏储备,为运动员选拔以及一般人体质评估提供一种客观量化的新指标。     

Glucose tolerance in young and older athletes and sedentary men

Groups of endurance-trained masters athletes (60 +/- 2 yr), older untrained men (62 +/- 1 yr), lean older untrained men (61 +/- 2 yr), endurance-trained young athletes (26 +/- 1 yr), and young untrained men (28 +/- 1 yr) were studied to obtain information on the separate effects of age, physical activity, and body fatness on glucose tolerance and insulin sensitivity. Each subject underwent an oral 100-g glucose tolerance test. Skinfold thickness was determined at six sites. The trained groups had a higher maximum O2 uptake capacity and lower sum of skinfolds than their sedentary peers. The lean older untrained group had a sum of skinfolds similar to that of the young untrained group. The masters athletes, young athletes, and young untrained men exhibited similar glucose tolerance whereas the two older untrained groups had an almost twofold greater total area under the glucose curve (P less than 0.05). The masters and young athletes had significantly blunted plasma insulin responses compared with the other three groups (P less than 0.05). The young and the lean older untrained groups had similar plasma insulin responses with significantly lower insulin levels than the older untrained group (P less than 0.05). These results provide evidence that regularly performed vigorous exercise can, in some individuals, prevent the deterioration of glucose tolerance and insulin sensitivity with age.     

Hypertrophic cardiomyopathy and sudden cardiac death due to physical exercise in Croatia in a 27-year period

The paper deals with the sudden cardiac death during physical exercise in males in Croatia. The data are a part of a retrospective study dealing with 69 sudden death due to physical activity in men in Croatia during 27 years: from January 1, 1984 to December 31, 2010. Three of them suddenly died during training and two of them died during recreational physical exercise, probably because of malignant ventricular arrhythmia due to hyperthrophic cardiomyopathy. One had an obstructive form of hypertrophic cardiomyopathy with i.v. septum of 40 mm and four had a non-obstructive forms of hyperthrophic cardiomyopathy with left ventricular wall of 18-20-22-25 mm. First athlete was a short trails runner, aged 24, with no any previous physical discomforts, who suddenly collapsed and died during training. The second athlete was a soccer player aged 18, with no any previous physical discomfort, who suddenly collapsed and died during training. The third aged 15, was a school boy, basketball player, with no any previous physical discomfort, who collapsed and died during training. Two aged 25 and 34, were with no physical discomfort during exercise and died suddenly during recreational soccer games. A sudden cardiac death due to physical exercise in young athletes in Croatia suffered of hyperthropic cardiomyopathy reached 0.06/100 000 yearly (p = 0.00000) in 27 years, in teenagers 0.26/100 000 (p = 0.00226), in teenagers suffered of hypertrophic cardiomyopathy reached 0.10/100 000 (p = 0.00000), in all young athletes suffered of other heart diseases reached 0.19/100 000 (p = 0.00005), and in the total male population aged 15 or more, engaged in sports and recreational physical exercise: 0.71/100.0000 (p = 0.00001).     

A hemodynamic comparison of young and older endurance athletes during exercise

This study assessed the hemodynamic responses to exercise of master athletes (56 +/- 5 yr of age) who placed in the top 10% of their age groups in local 10-km competitive events, competitive young runners (26 +/- 3 yr), young runners matched in training and performance to the master athletes (25 +/- 3 yr), and healthy older sedentary subjects (58 +/- 5 yr). The maximal O2 consumption (VO2max) of the master athletes was 9 and 19% lower than that of the matched young and competitive young runners, respectively. When compared at the same relative submaximal work rates, these three groups had similar stroke volumes and arteriovenous O2 (aVO2) differences, though the master athletes had lower VO2, cardiac output, and heart rate, and higher vascular resistance. The older sedentary group had a lower stroke volume, aVO2 difference, and higher vascular resistance than the master athletes. Maximal stroke volume and estimated aVO2 difference were the same in the three groups of athletes; the lower maximal heart rate of the master athletes appears to account for their lower VO2max. The older sedentary subjects' VO2max was 47% lower than that of the master athletes; this difference was almost equally the result of a lower stroke volume and a lower a-VO2 difference. Thus these older athletes did not exhibit the decline in maximum stroke volume and aVO2 difference that occurs with aging in sedentary individuals; they also appear to have retained a greater peripheral vasodilatory response than their sedentary peers.     

Physiological characteristics of system quanta of athletic performance

Physiological mechanisms of muscle activity during cyclic physical exercises of various intensity, including individual maximum exercise intensity, have been studied in 30 athletes. The system quantization of behavior showed that the spectral components of heart rate variability during attainment of individual maximum exercise intensity by athletes change in different directions. An increase in the individual maximum exercise intensity is accompanied by an increase in the maximum movement pace after each system quantum of muscle activity and is performed at a lower heart rate. This increases the absolute spectral power of the EEG β₂ range, and each system quantum of physical activity induces adequate triggering of autonomic mechanisms ensuring the activity. The results of this study may be used for professional selection or development of criteria of the endurance of athletes with regard to high cyclic exercise intensities.     

Heart rate and plasma catecholamines during 24 h of everyday life in trained and untrained men.

Physical training decreases resting heart rate as well as heart rate and catecholamine responses to ordinary physical activity and mental stress. These effects have been speculated to diminish cardiac morbidity. However, the sparing of heartbeats and catecholamine production might be outweighed by exaggerated responses during training sessions. To elucidate this issue, heart rate was measured continuously and plasma catecholamine concentrations were measured frequently during 24 h of ordinary living conditions in seven endurance-trained athletes (T) and eight sedentary or untrained (UT) young males. T subjects had lower heart rates than UT subjects during sleep and during nontraining awake periods. However, because of the increase during training, the total 24-h heartbeat number did not differ between groups (107,737 +/- 3,819 for T vs. 113,249 +/- 6,879 for UT, P = 0.731). Neither during sleep nor during awake nontraining periods were catecholamine levels lower in T than in UT subjects. Peak catecholamine levels during exercise in T were much higher than peak levels in UT subjects, and 24-h average epinephrine and norepinephrine concentrations were twice as high. We concluded that in highly trained athletes the total number of heartbeats per day is not decreased and the catecholamine production is, in fact, increased.     

The durations of the phases and periods of the cardiac cycle in athletes as dependent on the specific type of training

Polycardiography was used to analyze cardiac cycle phases in young track athletes during a two-year training cycle. The subjects were examined in the state of relative muscular rest and during moderate bicycle ergometer exercise. It was found that track training leads to a decrease in the heart rate and regulatory myocardial hypodynamic syndrome. Adaptive rearrangements in myocardial contractility were observed; they depended on the age of athletes and the type of training during the training macrocycle. The performance of the test with a moderate intensity was accompanied by a hyperdynamic syndrome, the degree of its manifestation depending on the age of the subject and the exercise intensity.     

Effects of heavy physical exercise and adaptogens on nitric oxide content in human saliva.

Since heavy physical exercise increases the content of nitric oxide and cortisol in blood and saliva, standardized extracts of the adaptogen herbal drugs Schizandra chinensis and Bryonia alba roots were applied to several groups of athletes in a placebo controlled double blind study. In the beginning of a test with athletes Schizandra chinensis and Bryonia alba extracts increased the concentration of NO and cortisol in blood plasma and saliva similar to athletes with heavy physical exercise. These results correlate with an increased physical performance in athletes taking adaptogens versus athletes taking placebo. In contrast after treatment with the adaptogen heavy physical exercise does not increase salivary NO and cortisol in athletes, whereas athletes treated with placebo heavy physical exercise increased salivary NO. These results show that the salivary NO test can be used both for evaluation of physical loading and stress protective effect of an adaptogen.     

A Broad-Based Estimation of the Physical Work Capacity of Young Men

The physical work capacity of young men (17–21 years old) was estimated during this broad-based study. The subjects were divided into two groups depending on the level of their motor activity: those who were in general sport fitness programs (166 subjects) and those who had achieved high recognition in sports (149 subjects). Two stages in the development of physical work capacity in young men were detected. The first stage covered the 17- to 18-year-old men and was characterized by a significant increase in physical development and aerobic capacity, the improved hemodynamic responses to physical exercise, and a high tension in the cardiac regulatory mechanisms. The second stage (18–21 years) was a period of relative stabilization of physical development and body functions, during which the organism came to a new functional level typical of adulthood. A comparative analysis of the physical work capacity in subjects with different levels of motor activity showed that the indices of physical development, physical fitness, and aerobic capacity in 17-year-old athletes exceeded the same indices in the untrained age-matched group. Physical work capacity was significantly higher in athletes than in the untrained subjects during the whole juvenile period. In athletes the age-related physical fitness and aerobic capacity increased to a greater extent but physical development increased to a lesser extent than the same in the untrained subjects.     

Cytokine response to strenuous exercise in athletes and non-athletes--an adaptive response

Exercise and physical strenuous activity have been demonstrated to increase the serum TNF-alpha and IL-6. Regular physical training is expected to attenuate such a response. This study was undertaken to understand the impact of regular exercise training on IL-6 and TNF-alpha in athletes and non-athletes. Ten athletes, who have been on regular training for the past 6 months, and 10 age- and sex-matched subjects (non-athlete group) who had no practice of regular exercise, were recruited. Both were subjected to undergo the same frequency level of strenuous exercise. Blood samples were collected; one before strenuous exercise and the other after the exercise. Plasma cytokines, IL-6 and TNF-alpha, were estimated using Sandwich ELISA method. All participants in the study were male with the athletes' age being 18.00+/-1.3years (mean+/-SD) and the non-athletes were aged 20.00+/-0.6years (mean+/-SD). Majority of the athletes and non-athletes demonstrated a rise in IL-6 and a fall in TNF-alpha levels. Further, the athletes showed a lesser magnitude of change in the cytokine levels following a longer duration of exercise than non-athletes. Athletes appear to have an attenuated cytokine response. Regular physical training has been demonstrated to attenuate the immune response to exercise in either direction.     

Effect of 10 days of physical inactivity on glucose tolerance in master athletes

Master athletes who exercise regularly appear to avoid the development of insulin resistance and deterioration of glucose tolerance (GT) commonly seen with aging. To evaluate the possibility that exercise prevents rather than masks the aging-related changes responsible for development of insulin resistance, we investigated the effects of 10 days of physical inactivity in 14 master athletes aged 61 +/- 2 (SE) yr. The response of 10 of these men to inactivity was similar to that of young athletes, with an unchanged plasma glucose response and a significantly greater insulin response to an oral glucose tolerance test (OGTT) after 10 days of inactivity. These 10 athletes appeared to have been protected against the aging-related changes in GT because their plasma glucose and insulin levels during the OGTT after 10 days of inactivity were not significantly different from those of young lean sedentary men. In contrast, a deterioration in GT occurred in four of the master athletes during 10 days of inactivity; this was sufficiently marked in two of them to be classified as impaired GT. We conclude that regular exercise may 1) protect against the development of insulin resistance and decline in GT with aging in individuals with normal GT and 2) normalize GT by means of short-term effects of exercise in some individuals with abnormal GT.     

Physical activity related to forced vital capacity and strength performance in a sample of young males and females

To identify the extent of physical performance differences between active and sedentary subjects taking into account sexual dimorphism physical activity level was recorded by interview from a sample of 319 young university students of both sexes. Anthropometric variables and physical performance values were obtained. The sex factor was the main variable explaining the differences in physical performance between active and sedentary young. Also contributors to those differences were forced vital capacity (FVC), heart rate after exercise and rest heart rate, together with the explosive component of strength (vertical jump). The effect of physical activity was shown in the increment of FVC and the decrease of resting heart rate. In the overall sample, heart rate after exercise, either in active males or active females, was lowered with respect to the sedentary subjects, showing that active females experienced a greater cardiovascular benefit following adaptation to training than sedentary.     

Cardiovascular adaptations to exercise training in the elderly

Maximal O2 uptake (VO2max) and left ventricular function decrease with age. Endurance exercise training of sufficient intensity, frequency, and duration increases VO2max in the elderly. The mechanisms underlying the increased VO2max in the elderly are enhanced O2 extraction of trained muscle during maximal exercise leading to a wider arteriovenous O2 difference, and higher cardiac output in the trained state. However, increased cardiac output during true maximal exercise has not been documented in elderly subjects. Endurance exercise training results in a lower heart rate and rate pressure product during submaximal exercise at a given intensity. However, no improvement in left ventricular function has been reported in the elderly after exercise training. Highly trained master athletes exhibit proportional increases in the left ventricular end-diastolic dimension and wall thickness suggestive of volume-overload hypertrophy compared with age-matched sedentary controls. The magnitude of left ventricular enlargement is similar to that in young athletes. The failure of exercise training to alter the age-related deterioration of left ventricular function in the elderly may reflect an insufficient training stimulus rather than the inability of the heart to adapt to training in elderly subjects.     

Comparison of blood pro/antioxidant levels before and after acute exercise in athletes and non-athletes

The aims of our study were to assess the redox state of adolescent athletes and non-athletes both at rest and after acute exposure to physical load and to find relations between parameters of redox state and morphofunctional characteristics of subjects. 58 young handball players and 37 non-athletes were subjected to body composition analysis, measuring of maximal oxygen consumption and blood sampling immediately before and after a maximal progressive exercise test. At rest, athletes had significantly higher superoxide dismutase (SOD) and catalase (CAT) activity, higher levels of glutathione (GSH) and nitric oxide (NO) and lower levels of lipid peroxidation (TBARS) compared with non-athletes. A maximal exercise test induced statistically significant rise of superoxide anion radical (O2-), hydrogen peroxide (H2O2) and NO levels in non-athletes, while TBARS levels decreased. Athletes experienced the fall in NO levels and the fall in CAT activity. After exercise, athletes had significantly lower levels of O2- compared with non-athletes. Two way repeated measures ANOVA showed that the response of O2-, NO and TBARS to the exercise test was dependent on the sports engagement (training experience) of subjects. Significant correlations between morphofunctional and redox parameters were found. These results suggest that physical fitness affects redox homeostasis.     

Invited Review: Dynamic exercise performance in Masters athletes: insight into the effects of primary human aging on physiological functional capacity.

Physiological functional capacity (PFC) is defined here as the ability to perform the physical tasks of daily life and the ease with which these tasks can be performed. For the past decade, we have sought to determine the effect of primary (healthy) adult human aging on PFC and the potential modulatory influences of gender and habitual aerobic exercise status on this process by studying young adult and Masters athletes. An initial approach to determining the effects of aging on PFC involved investigating changes in peak exercise performance with age in highly trained and competitive athletes. PFC, as assessed by running and swimming performance, decreased only modestly until age 60-70 yr but declined exponentially thereafter. A progressive reduction in maximal O2 consumption (V(O2 max)) appears to be the primary physiological mechanism associated with declines in endurance running performance with advancing age, along with a reduction in the exercise velocity at lactate threshold. Because V(O2 max) is important in mediating age-related reductions in exercise performance and PFC, we then investigated the modulatory influence of habitual aerobic exercise status on the rate of decline in V(O2 max) with age. Surprisingly, as a group, endurance-trained adults appear to undergo greater absolute rates of decline in V(O2 max) with advancing age compared with healthy sedentary adults. This appears to be mediated by a baseline effect (higher V(O2 max) as young adults) and/or a marked age-related decline in exercise training volume and intensity (stimulus) in endurance-trained adults. Thus the ability to maintain habitual physical activity levels with advancing age appears to be a critical determinant of changes in PFC in part via modulation of maximal aerobic capacity.     

Plasma protein carbonylation and physical exercise

Regular physical activity is associated with a reduced risk of coronary heart disease, as it probably modifies the balance between free-radical generation and antioxidant activity. On the other hand, however, acute physical activity increases oxygen uptake and leads to a temporary imbalance between the production of reactive oxygen and nitrogen species (RONS) and their disposal: this phenomenon is called oxidative stress. Proteins are one of the most important oxidation targets during physical exercise and carbonylation is one of the most common oxidative protein modifications. In cells there is a physiological level of oxidized proteins that doesn't interfere with cell function; however, an increase in oxidized protein levels may cause a series of cellular malfunctions that could lead to a disease state. For this reason the quantification of protein oxidation is important to distinguish a healthy state from a disease state. Several studies have demonstrated an increase of carbonylated plasma proteins in athletes after exercise, but none have identified targets of this oxidation. Recently a process of protein decarbonylation has been discovered, this may indicate that carbonylation could be involved in signal transduction. The aim of our research was to characterize plasma protein carbonylation in response to physical exercise in trained male endurance athletes. We analyzed by proteomic approach their plasma proteins at resting condition and after two different kinds of physical exercise (PE). We used 2D-GE followed by western blot with specific antibodies against carbonylated proteins. The 2D analysis identified Haptoglobin as potential protein target of carbonylation after PE. We also identified Serotransferrin and Fibrinogen whose carbonylation is reduced after exercise. These methods have allowed us to obtain an overview of plasma protein oxidation after physical exercise.     

The effect of short-term Swiss ball training on core stability and running economy

The purpose of this study was to investigate the effect of a short-term Swiss ball training on core stability and running economy. Eighteen young male athletes (15.5 +/- 1.4 years; 62.5 +/- 4.7 kg; sigma9 skinfolds 78.9 +/- 28.2 mm; VO2max 55.3 +/- 5.7 ml.kg(-1).min(-1)) were divided into a control (n = 10) and experimental (n = 8) groups. Athletes were assessed before and after the training program for stature, body mass, core stability, electromyographic activity of the abdominal and back muscles, treadmill VO2max, running economy, and running posture. The experimental group performed 2 Swiss ball training sessions per week for 6 weeks. Data analysis revealed a significant effect of Swiss ball training on core stability in the experimental group (p < 0.05). No significant differences were observed for myoelectric activity of the abdominal and back muscles, treadmill VO2max, running economy, or running posture in either group. It appears Swiss ball training may positively affect core stability without concomitant improvements in physical performance in young athletes. Specificity of exercise selection should be considered.