Concentric left ventricular morphology in aerobically trained kayak canoeists

The aim of the present study was to test the hypothesis that upper body aerobically trained athletes (kayak canoeists) would have greater left ventricular wall thickness, but similar left ventricular diastolic chamber dimensions, compared with recreationally active and sedentary men. Ultrasound echocardiography was used to determine cardiac structure and function in highly trained kayak canoeists (n?=?10), moderately active (n?=?10) and sedentary men (n?=?10). The septal and posterior left ventricular walls were ～0.2?cm thicker in kayak canoeists (P?<?0.05), and left ventricular mass was 51% and 32% greater (P?<?0.05) in canoeists than in the sedentary and moderately trained participants, respectively. There were no differences in left ventricular chamber dimension, suggesting that the kayak canoeists had a concentric pattern of left ventricular adaptation to aerobic upper body training. Scaling the data to body composition indices had no effect on the outcome of the statistical analysis. There were no differences in resting Doppler left ventricular diastolic or systolic function among the groups. Ejection fraction was lower in the kayak canoeists, but the magnitude of the difference was within the normal variability for this measurement. Thus aerobically upper body trained athletes demonstrated a concentric pattern of cardiac enlargement, but resting left ventricle function was not different between athletes, moderately active and sedentary individuals.     

Left ventricular morphology and function in endurance-trained female athletes

In this study,we investigated resting left ventricular dimensions and function in trained female rowers, canoeists and cyclists. In male populations, such athletes have demonstrated the largest left ventricular wall thicknesses and cavity dimensions. Echocardiograms were analysed from 24 athletes (rowers and canoeists, n=12; cyclists, n=12) and 21 age-matched controls to measure left ventricular end-diastolic dimension and volume, and septal (ST) and posterior wall (PWT) thicknesses. Left ventricular mass was calculated from M-mode data. Systolic and diastolic function were calculated from M-mode and Doppler echocardiography, respectively. Height, body mass, body surface area and fat-free mass were determined anthropometrically. The athletes were well matched with the controls for all anthropometric variables except fat-free mass (rowers and canoeists 49.7 3.6 kg, cyclists 48.0?+\- 3.8 kg, controls 45.0?+\- 5.4 kg; P < 0.05). The left ventricular end-diastolic dimension, mass and volume, and septal and posterior wall thicknesses, were all significantly greater in the athletes than the controls (P < 0.05). These differences persisted (except for left ventricular end-diastolic dimension) even after allometric adjustment for group differences in fat-free mass. Stroke volume was larger (rowers and canoeists 102?+\- 13 ml, cyclists 103?+\0 16 ml, controls 80?+\- 15 ml; P < 0.05) in both groups of athletes but all other functional data were similar between groups. As in male athletes, female rowers, canoeists and cyclists displayed significantly larger left ventricular cavity dimensions and wall thicknesses than controls.     

Left ventricular morphology and function in endurance-trained female athletes.

In this study, we investigated resting left ventricular dimensions and function in trained female rowers, canoeists and cyclists. In male populations, such athletes have demonstrated the largest left ventricular wall thicknesses and cavity dimensions. Echocardiograms were analysed from 24 athletes (rowers and canoeists, n = 12; cyclists, n = 12) and 21 age-matched controls to measure left ventricular end-diastolic dimension and volume, and septal (ST) and posterior wall (PWT) thicknesses. Left ventricular mass was calculated from M-mode data. Systolic and diastolic function were calculated from M-mode and Doppler echocardiography, respectively. Height, body mass, body surface area and fat-free mass were determined anthropometrically. The athletes were well matched with the controls for all anthropometric variables except fat-free mass (rowers and canoeists 49.7+/-3.6 kg, cyclists 48.0+/-3.8 kg, controls 45.0+/-5.4 kg; P < 0.05). The left ventricular end-diastolic dimension, mass and volume, and septal and posterior wall thicknesses, were all significantly greater in the athletes than the controls (P < 0.05). These differences persisted (except for left ventricular end-diastolic dimension) even after allometric adjustment for group differences in fat-free mass. Stroke volume was larger (rowers and canoeists 102+/-13 ml, cyclists 103+/-16 ml, controls 80+/-15 ml; P < 0.05) in both groups of athletes but all other functional data were similar between groups. As in male athletes, female rowers, canoeists and cyclists displayed significantly larger left ventricular cavity dimensions and wall thicknesses than controls.     

青少年足球运动员左室肥厚的生理极限研究

目的:确定青少年足球运动员左室肥厚的生理极限值,预防运动员运动性猝死的发生风险。方法:采用超声心动仪检测60名优秀青少年足球运动员和60名年龄、性别类似的健康对照者及40名其他项目运动员的左心室厚度。结果:与对照组相比,青少年足球运动员的左心室壁厚度(LVWT)较大,为9.5±1.7mm,对照组为8.4±1.4mm。其中5名运动员(8.3%)的最大LVWT超过了预测值的上限;只有1名男运动员的绝对LVWT值大于12mm(1.7%)。5名运动员的LVWT超过了预测限度,提示左心腔扩大(54.4±2.1mm;范围为52~60mm)。而女运动员LVWT值均小于11 mm。结论:与非运动员相比,有训练的青少年足球运动员的LVWT值更大。只有一小部分运动员的LVWT超过了上限,但少有大于12mm,而腔室一般都有扩大现象。提示,当有训练的青少年足球运动员男子LVWT>12mm,女子>11mm,极有可能属于肥厚性心肌病。     

Standardization indices of cardiac hypertrophy in weight lifters

In order to investigate further the use of standardization procedures to determine training effects on cardiac dimension and function, two groups of subjects were analysed noninvasively. A control group of sedentary men (n = 7) and an experimental group of weight lifters (n = 12) volunteered for a standard M-mode echocardiographic assessment. Indices of cardiac function as well as absolute left ventricular dimensions and left ventricular mass were similar between the groups. Standardizing for body surface area and body weight separated the groups. The weight lifters were shown to have a more muscular left ventricular posterior wall. The weight lifters also demonstrated a dilated left ventricle when indexing for body surface area. All other dimensional and volumetric indices were non-significant. The present investigation underlines the need for matching control and experimental groups to biometric variables in order to avoid misinterpreting cardiac enlargement. There is evidence for a true relative hypertrophy in weight lifters as indicated by similar absolute cardiac dimensions and similar biometric variables. Therefore, when evaluating athletes engaged in a chronic pressure overload, cardiac hypertrophy indices should consider body surface area (BSA), body weight and lean body weight (LBW). Future work in this field should incorporate rigorous controls on all biometric variables for better interpretation of hypertrophy in relative or absolute terms.     

我国优秀皮划艇运动员有氧能力的评价

目的:探讨我国优秀皮划艇运动员有氧能力的评价方法,为制定针对性的训练计划提供参考。方法:以备战伦敦奥运会国家皮划艇队运动员为研究对象,包括8名男子皮艇、7名女子皮艇和6名划艇运动员。利用皮划艇测功仪采用逐级递增负荷至力竭测最大摄氧量、利用4级1 000 m递增强度划船测试乳酸阈(4 mmol/l对应的船速)。结果:伦敦奥运周期我国优秀男子皮艇、女子皮艇和划艇运动员的绝对最大摄氧量分别为(5.25±0.22)l/min、(3.58±0.22)l/min、(4.85±0.13)l/min;相对最大摄氧量分别为(57.28±3.8 1)ml/(kg·min-1)、(50.92±3.78)ml/(kg·min-1)、(54.72±5.3)1ml/(kg·min-1),,经过3个月训练后男子皮艇和划艇运动员最大摄氧量无明显变化,女子皮艇运动员明显提高;男子皮艇、女子皮艇和划艇运动员乳酸阈船速经过3个月的训练后都明显提高,提高幅度分别为11.92%、3.77%和14.37%。结论:我国伦敦周期优秀皮划艇运动员的最大摄氧量高于国际优秀皮划艇运动员的平均水平,和最大摄氧量比较,乳酸阈表现出更好的训练可塑性,能够更为准确的反映皮划艇运动员有氧能力的动态变化。     

Does local dynamic stability of kayak paddling technique affect the sports performance? A pilot study

During competition, kayak athletes must optimally adapt to environmental factors (e.g. wind, waves) to achieve peak performance. However, the ability to adapt to such perturbations has never been assessed in kayak paddling. Therefore, the aim of the current study was to evaluate the local dynamic stability in sports technique of youth sprint kayak athletes. In a cross-sectional study, 14 healthy male athletes were recruited from an elite youth sprint kayak squad. During an incremental kayak ergometer test, mean power, heart rates and local dynamic technique stability of hands, arms, trunk and paddle were registered and the association with the athletes 2000?m free-water times were estimated using mixed models. The 2000?m free-water performance significantly predicted the paddles (p?=?.037) local dynamic stability whereas no association was found for the trunk or the upper extremity kinematics. In conclusion, kayak athletes with high-performance capability over 2000?m paddling depict high local dynamic technique stability. This emphasizes the importance of a stable technique for advanced kayak skills, especially regarding paddling movements.     

对大连市航海运动学校皮划艇运动员运动损伤的调查分析

文章通过运用问卷调查法等多种研究方法,对大连市航海运动学校划艇运动员常见运动损伤调查分析进行研究。结果显示:皮划艇运动员运动损伤在一年内经常发生,其中腰部和肩部由于是皮划艇运动的常用发力部位,所以是损伤发生的主要集中部位,春季和冬季由于人体的粘滞性高,所以出现损伤的季节主要是春季和冬季,而对于损伤原因的探究发现损伤主要是由身体疲劳所致。     

Sedentary behaviour and adiposity in elite athletes

Abstract

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a health risk. Even in athletes an increased adiposity affects health and performance. Sedentary behaviour has been associated with higher levels of adiposity, independent of moderate-to-vigorous physical activity. However, it is unclear whether this independent relationship still exists in highly trained athletes. The aim of this study was to examine the association of sedentary behaviour with body fatness in elite athletes. Cross-sectional data from 82 male athletes (mean age 22 years) were used. Total and regional body composition was measured by dual energy X-ray absorptiometry. Self-reported time spent in sedentary behaviour and weekly training time was assessed in all participants at one time point and multiple regression analyses were used. Sedentary behaviour predicted total fat mass (β = 0.77; 95% CI: 0.36–1.19, P < 0.001) and trunk fat mass (β = 0.25; 95% CI: 0.07–0.43, P = 0.007), independent of age, weekly training time, and residual mass (calculated as weight-dependent variable) but not abdominal fat. Also, no associations of sedentary behaviour with fat-free mass, appendicular lean soft tissue, and body mass index were found. These findings indicate that athletes with higher amounts of sedentary behaviour presented higher levels of total and trunk fatness, regardless of age, weekly training time, and residual mass. Therefore, even high moderate-to-vigorous physical activity levels do not mitigate the associations between sedentary behaviour and body fatness in highly trained athletes.     

Differences in energy expenditure between high- and low-volume training

Abstract

Several studies have examined energy expenditure in various sports but there is a lack of research on the contribution of exercise and habitual activity during different training periods. This study examined changes in total daily energy expenditure (TDEE) and its components during high- and low-volume training periods. Further, changes in time spent in sedentary, light, moderate and vigorous activity in response to different training volumes were explored. Energy expenditure was measured in 15 male endurance athletes during 2 non-consecutive weeks – 1 week of high volume (>13 hours) training and another week of low volume (<7 hours) training. The SenseWear Pro 3 Armband, individual heart-rate-oxygen consumption regression and indirect calorimetry was used to measure non-exercise activity thermogensis (NEAT), exercise energy expenditure (EEE) and resting metabolic rate, respectively. Time spent at different intensities was assessed using previously established MET cutpoints. TDEE as well as EEE increased significantly with higher training volume, while no difference in NEAT occurred. Further, significantly less time was spent in sedentary activities during the high-volume week. These results suggest that highly trained athletes do not compensate for increased training volume and reduce sedentary activities to allow for more training time.     

Echocardiographic dimensions in trained and untrained 12-year-old boys and girls

The purpose of this study was to compare echocardiographically measured left ventricular (LV) dimensions of 85 trained 11-12-year-old athletes with 106 untrained children matched for skeletal age and fat-free mass. Training status for each group applied to the 3 years prior to the measurements. It was found that 12 min and 100 m runs demonstrated the superior athletic ability of the trained children, but there were no significant differences in LV internal diameters at diastole and systole, in LV posterior wall thickness, or in LV end-diastolic volume and LV mass. These data indicate that little difference occurs in LV size between moderately trained and untrained 11-12-year olds or between boys and girls matched for fat-free mass and skeletal age. It is also evident that consistent but moderate training during late pre-adolescence has little effect on LV development.     

Global and regional cardiac function in lifelong endurance athletes with and without myocardial fibrosis

The aim of the present study was to compare cardiac structure as well as global and regional cardiac function in athletes with and without myocardial fibrosis (MF). Cardiac magnetic resonance imaging with late gadolinium enhancement was used to detect MF and global cardiac structure in nine lifelong veteran endurance athletes (58?±?5 years, 43?±?5 years of training). Transthoracic echocardiography using tissue-Doppler and myocardial strain imaging assessed global and regional (18 segments) longitudinal left ventricular function. MF was present in four athletes (range 1–8?g) and not present in five athletes. MF was located near the insertion points of the right ventricular free wall on the left ventricle in three athletes and in the epicardial lateral wall in one athlete. Athletes with MF demonstrated a larger end diastolic volume (205?±?24 vs 173?±?18?ml) and posterior wall thickness (11?±?1 vs 9?±?1?mm) compared to those without MF. The presence of MF did not mediate global tissue velocities or global longitudinal strain and strain rate; however, regional analysis of longitudinal strain demonstrated reduced function in some fibrotic regions. Furthermore, base to apex gradient was affected in three out of four athletes with MF. Lifelong veteran endurance athletes with MF demonstrate larger cardiac dimensions and normal global cardiac function. Fibrotic areas may demonstrate some co-localised regional cardiac dysfunction, evidenced by an affected cardiac strain and base to apex gradient. These data emphasize the heterogeneous phenotype of MF in athletes.     

皮划艇运动员在不同负荷状态下左心功能的研究

采用实验法,对皮划艇运动员不同负荷状态下左心功能的研究。结果发现,1 )运动员的心率出现安静时机能节省化、定量负荷反应低、恢复快等特点。运动员组心率恢复速度快于对照组;2 )无论处于何种状态,运动员组的左室射血时间均显著长于对照组,提示,其每搏输出量始终大于对照组,可视作训练程度高、训练效果佳的重要特征等     

恒定负荷运动中和运动后左室舒张功能的变化

采用脉冲多谱勒超声心动图观察运动中和运动后左室舒张功能的变化。研究结果显示运动时随强度的增加舒张早期最大的峰值速度E峰峰值流速、舒张晚期最大的峰值速度A峰峰值流速，舒张早期最大瞬时压差(PPGE)、舒张末期最大瞬时压差(PPGA)增加，但vE／vA值下降。其动力来源可能与运动时左室的收缩功能提高有关。运动后恢复期E峰、A峰峰值流速，PPGE、PPGA逐渐减少，vE／vA值逐渐增大，并很快恢复到安静状态。     

男子皮艇运动员周期训练时Hb、CK、BUN的变化特点

目的：探讨皮艇运动训练周期内的训练特点与运动员生化指标变化之间的关系和规律。方法：在皮艇运动训练周,对12名某队男子皮艇运动员的常规生化指标：血红蛋白（Hb）、血清肌酸激酶（CK）、血尿素氮（BUN）进行测试。结果：男子皮艇运动员BUN、Hb周期训练前的值处于正常人的范围,但个体差异较大;CK值高于正常人的范围;在整个训练周期,BUN,CK、Hb等指标随着训练周期训练方法的变化有周期性变化。结论与建议：BUN、CK和Hb各指标存在着不同程度的个体差异,纵向和横向综合比较BUN、CK、Hb指标对皮艇训练监控更有意义,不能以单一指标作为增加运动量或增加运动强度的标准;周期性训练模式既可以提高运动负荷能力又可以避免由于运动负荷对机体刺激过深产生过度疲劳。     

The dynamics of elite paddling on a kayak simulator

During kayak paddling, athletes attempt to maximize kayak velocity with the generation of optimal paddle forces. The aim of the current study was to examine ten elite kayakers and identify a number of key biomechanical performance variables during maximal paddling on a custom kayak simulator. These included analysing the effect of side (left and right) and period (beginning, middle, and end of the kayak simulation) on paddle force, paddle angle, mechanical efficiency, and stroke timing data. Paddle kinetics and kinematics were measured with strain gauge force transducers attached to either end of the ergometer paddle and using a 3D motion analysis system respectively. Results indicated a significantly greater mechanical efficiency during the right paddle stroke compared with the left (P < 0.025). In addition, analysing the effect of period, peak paddle force demonstrated a significant reduction when comparing the beginning to the middle and end of the simulated race respectively (P < 0.025). Examination of individual force profiles revealed considerable individuality, with significant variation in the time course of force application. Analysis of the profiles presented may provide meaningful feedback for kayakers and their coaches.     

过度运动对大鼠左心室舒张功能的影响

本实验采用８项反映心室舒张功能血流动力学指标对２０只大鼠力竭游泳运动后心脏功能变化进行测试研究．结果表明，力竭运动后，８项心室舒开张功能指标发生明显改变（Ｐ＜０．０１），说明力竭运动对心脏的舒张功能有明显的损害作用．这一结果为运动伤病的防治提供了实验资料。     

Cardiac Dimensions in Elite Young Track Athletes

The purpose of the study was to compare young sprint and distance runners for changes in their cardiac dimensions with increased age (10–17 years) or body surface area (1–2 m²). Echocardiographic dimensions were obtained on 73 male track athletes competing in the 1983 National Age Group Track and Field Association championships. Each group of athletes was also compared with a hypothetical normal population (matched for weight and age) generated from prediction equations derived by Henry, Gardin, & Ware (1980). The cardiac dimensions examined were: Left ventricular internal diameter, left ventricular posterior wall thickness, and interventricular septum thickness. The male distance runners (n = 38) had a significantly greater increase in left ventricular posterior wall thickness and interventricular septum thickness with increasing age or increasing body surface area compared to the sprinters (n = 35) or compared to the predicted normal population. The left ventricular internal diameter was not significantly different between the groups. These results indicate that the hearts of male distance runners are undergoing a training hypertrophy whereas the hearts of sprinters are no different than hearts in a normal population. The changes in cardiac dimensions of these young athletes run counter to the generalizations stated for adult athletes: That endurance training enlarges the left ventricular internal diameter, but does not increase the left ventricular posterior wall or interventricular septum thickness.     

不同专项运动训练对男大学生运动员骨密度的影响

目的探讨不同专项运动训练对男大学生运动员身体各部位骨密度(BMD)的影响。方法对网球专项、足球专项训练的男性大学生运动员各15名,无正规运动训练同龄大学生15名(对照组)进行BMD测试,测试部位分别为:左右前臂各区域、左右侧股骨各区域骨密度值。结果 2组训练组各部位BMD与对照组比较,均有升高的趋势,且大部分区域具有显著性差异;网球专项组与足球专项组比较,左右前臂有升高的趋势,其中一部分区域BMD有显著性差异,左右侧股骨BMD差异不明显。结论不同专项运动对不同部位的骨密度值影响有差异,运动训练能有效地提高男大学生机体的BMD及身体素质。