			Home About us Contact

Endurance Athletes (endurance + athlete)

Distribution by Scientific Domains

Medical Sciences	62%
Life Sciences	37%

Kinds of Endurance Athletes

elite endurance athlete

Selected Abstracts

Echocardiographic Doppler Evaluation of Left Ventricular Diastolic Filling in Older, Highly Trained Male Endurance Athletes

ECHOCARDIOGRAPHY, Issue 1 2000
PETER R. JUNGBLUT M.D.
Previously published data have suggested that endurance training does not retard the normative aging impairment of early left ventricular diastolic filling (LVDF). Those studies, suggesting no effect of exercise training, have not examined highly trained endurance athletes or their LVDF responses after exercise. We therefore compared LVDF characteristics in a group of older highly trained endurance athletes (n= 12, mean age 69 years, range 65,75) and a group of sedentary control subjects (n= 12, mean age 69 years, range 65,73) with no cardiovascular disease. For all subjects, M-mode and Doppler echocardiographic data were obtained at rest. After baseline studies, subjects underwent graded, maximal cardiopulmonary treadmill exercise testing using a modified Balke protocol. Breath-by-breath respiratory gas analysis and peak exercise oxygen consumption (VO2max) measurements were obtained. Immediately after exercise and at 3,6 minutes into recovery, repeat Doppler echocardiographic data were obtained for determination of LVDF parameters. VO2max (44 ± 6.3 vs 27 ± 4.2 mllkglmin, P< 0.001), oxygen consumption at anaerobic threshold (35 ± 5.4 vs 24 ± 3.8 mllkglmin, P< 0.001), exercise duration (24 ± 3 vs 12 ± 6 minutes, P< 0.001), and left ventricular mass index (61 ± 13 vs 51 ± 7.8 kglm2, P< 0.05) were greater in endurance athletes than in sedentary control subjects, whereas body mass index was lower (22 ± 1.7 vs 26 ± 3.4 kglm2, P< 0.001). No differences in any of the LVDF characteristics were observed between the groups with the exception of a trend toward a lower atrial filling fraction at rest in the endurance athlete group versus the control subjects (P= 0.07). High-intensity endurance exercise training promotes exceptional peak exercise oxygen consumption and cardiovascular stamina but does not appear to alter normative aging effects on left ventricular diastolic function. (ECHOCARDIOGRAPHY, Volume 17, January 2000) [source]

Antioxidant Requirements of Endurance Athletes: Implications for Health

NUTRITION REVIEWS, Issue 3 2006
Sarah L. Williams BSc (Hons)
This review discusses studies investigating the effects of antioxidant supplementation on exercise-induced oxidative stress with a focus on the health implications. The aim is to determine antioxidant requirements for endurance athletes. Overall, differences in methodology make it difficult to compare the relatively small number of published studies on this topic. The types of studies needed to more adequately assess the health effects of antioxidant supplements in athletes (long-term interventions with hard end points) have not been done. Therefore, there is currently insufficient evidence to recommend antioxidant supplements for endurance athletes. [source]

The guanine nucleotide binding protein , polypeptide 3 gene C825T polymorphism is associated with elite endurance athletes

EXPERIMENTAL PHYSIOLOGY, Issue 3 2009
Nir Eynon
A functional C825T polymorphism in the human guanine nucleotide binding protein , polypeptide 3 (GNB3) gene has been associated with enhanced G protein activation. Since reports regarding the interaction between physical activity and the GNB3 C825T polymorphism are limited and inconsistent, the aim of this study was to determine the frequency of C825T alleles among 155 elite Israeli athletes (endurance athletes and sprinters) and 234 healthy control subjects. Genotyping for GNB3 C825T was performed using polymerase chain reaction on DNA from leucocytes. Results showed that there was a significant difference in GNB3 C825T polymorphism genotype frequencies between endurance athletes and sprinters (P= 0.045) as well as between endurance athletes and control subjects (P= 0.046). We also observed a significantly higher proportion of the GNB3 TT genotype in the group of endurance athletes (19%) compared with the sprinters (5%, P= 0.014) and the control subjects (8.5%, P= 0.026). In the group of athletes, the odds ratio of GNB3 TT genotype being an endurance athlete was 4.49 (95% confidence interval 1.4,14.3) and of GNB3 CC genotype was 0.91 (95% confidence interval 0.47,1.77). These results were even more pronounced when we compared between the subgroups of 20 top-level endurance athletes and 24 top-level sprinters. We conclude that in Israeli athletes the GNB3 TT genotype is higher in elite endurance athletes than it is in sprinters, and within the endurance group it is higher in top-level athletes, suggesting a positive association between the TT genotype and the likelihood of being an elite endurance athlete. [source]

Disparity in regional and systemic circulatory capacities: do they affect the regulation of the circulation?

ACTA PHYSIOLOGICA, Issue 4 2010
J. A. L. Calbet
Abstract In this review we integrate ideas about regional and systemic circulatory capacities and the balance between skeletal muscle blood flow and cardiac output during heavy exercise in humans. In the first part of the review we discuss issues related to the pumping capacity of the heart and the vasodilator capacity of skeletal muscle. The issue is that skeletal muscle has a vast capacity to vasodilate during exercise [,300 mL (100 g),1 min,1], but the pumping capacity of the human heart is limited to 20,25 L min,1 in untrained subjects and ,35 L min,1 in elite endurance athletes. This means that when more than 7,10 kg of muscle is active during heavy exercise, perfusion of the contracting muscles must be limited or mean arterial pressure will fall. In the second part of the review we emphasize that there is an interplay between sympathetic vasoconstriction and metabolic vasodilation that limits blood flow to contracting muscles to maintain mean arterial pressure. Vasoconstriction in larger vessels continues while constriction in smaller vessels is blunted permitting total muscle blood flow to be limited but distributed more optimally. This interplay between sympathetic constriction and metabolic dilation during heavy whole-body exercise is likely responsible for the very high levels of oxygen extraction seen in contracting skeletal muscle. It also explains why infusing vasodilators in the contracting muscles does not increase oxygen uptake in the muscle. Finally, when ,80% of cardiac output is directed towards contracting skeletal muscle modest vasoconstriction in the active muscles can evoke marked changes in arterial pressure. [source]

"Supranormal" Cardiac Function in Athletes Related to Better Arterial and Endothelial Function

ECHOCARDIOGRAPHY, Issue 6 2010
Maria Florescu M.D.
Objective: Athlete's heart is associated with left ventricular (LV) hypertrophy (LVH), and "supranormal" cardiac function, suggesting that this is a physiological process. Hypertrophy alone cannot explain increase in cardiac function, therefore, other mechanisms, such as better ventriculo-arterial coupling might be involved. Methods: We studied 60 male (21 ± 3 years) subjects: 27 endurance athletes, and a control group of 33 age-matched sedentary subjects. We assessed global systolic and diastolic LV function, short- and long-axis myocardial velocities, arterial structure and function and ventriculo-arterial coupling, endothelial function by flow-mediated dilatation, and amino-terminal pro-brain natriuretic peptide (NT-proBNP) and biological markers of myocardial fibrosis and of oxidative stress. Results: Athletes had "supranormal" LV longitudinal function (12.4 ± 1.0 vs 10.1 ± 1.4 cm/s for longitudinal systolic velocity, and 17.4 ± 2.6 vs 15.1 ± 2.4 cm/s for longitudinal early diastolic velocity, both P < 0.01), whereas ejection fraction and short-axis function were similar to controls. Meanwhile, they had better endothelial function (16.7 ± 7.0 vs 13.3 ± 5.3%, P < 0.05) and lower arterial stiffness (pulse wave velocity 7.1 ± 0.6 vs 8.8 ± 1.1 m/s, P = 0.0001), related to lower oxidative stress (0.259 ± 0.71 vs 0.428 ± 0.88 nmol/mL, P = 0.0001), with improved ventriculo-arterial coupling (37.1 ± 21.5 vs 15.5 ± 13.4 mmHg.m/s3× 103, P = 0.0001). NT-proBNP and markers of myocardial fibrosis were not different from controls. LV longitudinal function was directly related to ventriculo-arterial coupling, and inversely related to arterial stiffness and to oxidative stress. Conclusions: "Supranormal" cardiac function in athletes is due to better endothelial and arterial function, related to lower oxidative stress, with optimized ventriculo-arterial coupling; athlete's heart is purely a physiological phenomenon, associated with "supranormal" cardiac function, and there are no markers of myocardial fibrosis. (Echocardiography 2010;27:659-667) [source]

Echocardiographic Doppler Evaluation of Left Ventricular Diastolic Filling in Older, Highly Trained Male Endurance Athletes

ACE and angiotensinogen gene genotypes and left ventricular mass in athletes

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2001
F. Diet
Background Genetic factors may be important in modifying heart size due to long-term athletic training. The significance of polymorphisms of genes of the renin,angiotensin system in myocardial mass in a population of athletes participating in different disciplines is not known. Methods The angiotensin I-converting enzyme gene insertion/deletion (I/D) polymorphism, angiotensinogen gene M235T polymorphism and angiotensin II type 1 receptor gene A1166C polymorphism were determined in 83 male Caucasian endurance athletes and associated with left ventricular mass. Results No association with left ventricular mass was found for the polymorphisms of angiotensin I-converting enzyme gene I/D, angiotensinogen gene M235T and angiotensin II type 1 gene A1166C when studied separately. However, combined analysis of the angiotensin I-converting enzyme gene I/D polymorphism and angiotensinogen gene M235T polymorphism genotypes suggested an association with left ventricular mass (g m,2) (P = 0·023). Athletes with the angiotensin I-converting enzyme gene DD/angiotensinogen gene TT genotype combination had greater left ventricular mass compared with all other genotype combinations (179·8 ± 26·1 g m,2 vs. 145·2 ± 27·3 g m,2, P = 0·003). Conclusions These results suggest an association of combined angiotensin I-converting enzyme gene I/D polymorphism genotypes, and angiotensinogen gene M235T polymorphism genotypes with left ventricular hypertrophy due to long-term athletic training. A synergistic effect of angiotensin I-converting enzyme gene DD genotype and angiotensinogen gene TT genotype on left ventricular mass in endurance athletes appears to occur. [source]

The guanine nucleotide binding protein , polypeptide 3 gene C825T polymorphism is associated with elite endurance athletes

Ventilatory control in humans: constraints and limitations

EXPERIMENTAL PHYSIOLOGY, Issue 2 2007
Susan A. Ward
Below the lactate threshold (,L), ventilation responds in close proportion to CO2 output to regulate arterial partial pressure of CO2. While ventilatory control models have traditionally included proportional feedback (central and carotid chemosensory) and feedforward (central and peripheral neurogenic) elements, the mechanisms involved remain unclear. Regardless, putative control schemes have to accommodate the close dynamic ,coupling' between and . Above ,L, is driven down to constrain the fall of arterial pH by a compensatory hyperventilation, probably of carotid body origin. When requirements are high (as in highly fit endurance athletes), can attain limiting proportions. Not only does this impair gas exchange at these work rates, but there may be an associated high metabolic cost for generation of respiratory muscle power, which may be sufficient to divert a fraction of the cardiac output away from the muscles of locomotion to the respiratory muscles, further compromising exercise tolerance. [source]

Red Cell Pulmonary Transit Times Through the Healthy Human Lung

EXPERIMENTAL PHYSIOLOGY, Issue 2 2003
G. S. Zavorsky
It has previously been postulated that rapid red cell capillary transit through the human lung plays a role in the mechanism of diffusion limitation in some endurance athletes. Methodological limitations currently prevent researchers from directly measuring pulmonary capillary transit times in humans during exercise; however, first pass radionuclide cardiography allows direct measurement of red blood cell (RBC) transit times through the whole lung at various exercise intensities. We examined the relationship between mean whole lung red cell pulmonary transit times (cardiopulmonary transit times or CPTT) and different levels of flow in 88 healthy humans (76 males, 12 females) from several studies (mean age 31 years). The pooled data suggest that the relationship between CPTT and cardiac index (CI), beginning at rest and progressing through to maximum exercise demonstrates that CPTT reaches its minimum value when CI is about 8.1 l m2 min,1 (2.5-3 times the CI value at rest), and does not significantly change with further increases in CI. Cardiopulmonary blood volume (CPBV) index also does not change significantly until CI reaches 2.5 to 3 times the CI value at rest and then increases roughly linearly after that point. Consequently, the systematic increase in CPBV index with increasing pulmonary blood flow between 8.1 and 20 l m2 min,1 displays an adaptive response of the cardiopulmonary system by augmenting CPBV (and perhaps pulmonary capillary blood volume through distension and recruitment) to offset the reduction in CPTT, as no significant difference in mean CPTT is observed between these levels of flow (P > 0.05). Therefore, these data demonstrate that CPBV does not reach maximum capacity during strenuous or maximum exercise. This does not support the principle of quarter-power allometric scaling for flow when explaining modifications during exercise. Therefore, we speculate that the observed relationships between CPTT, CBPV index and flow may prevent mean CPTT (and perhaps mean pulmonary capillary transit times) from decreasing below the threshold time required for oxygenation. [source]

The utility of immature reticulocyte fraction as an indicator of erythropoietic response to altitude training in elite cyclists

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p2 2010
V. S. NADARAJAN
Summary Altitude training is sometimes employed by elite endurance athletes to improve their sea level performance. This improvement results from the increased red cell mass consequent upon the boost in erythropoietin (EPO) level that occurs as a response to the relatively hypoxic environment at high altitudes. We measured serum EPO levels together with various red cell and reticulocyte parameters including immature reticulocyte fraction (IRF) in eight national track-endurance cyclists, resident at sea-level, prior to and upon return from an altitude of approximately 1905 m. Reticulocytes and soluble transferrin receptor (sTfR) were significantly increased with reduction in ferritin levels immediately on return from high altitude indicating increased erythropoietic activity. IRF in particular showed a significant peak immediately on return but decline to sub-baseline levels by day 9, and recovery to baseline by day 16. Our results indicate that IRF is a sensitive marker of erythropoietic status in athletes undergoing altitude training and subsequent loss of EPO stimuli on return to sea level. [source]

Soldiers With Musculoskeletal Injuries

JOURNAL OF NURSING SCHOLARSHIP, Issue 3 2008
Bonnie M. Jennings
Purpose: To describe Soldiers' (e.g., U.S. Army personnel) perspectives of the effect of musculoskeletal injuries. Design: Data were collected in the summer of 2003 using a prospective survey design. The survey was mailed to active duty Soldiers on modified work plans because of musculoskeletal injuries. These Soldiers were assigned to one Army installation in the US. Methods: Responses to the survey questions were analyzed using descriptive statistics. The numerous handwritten comments were evaluated qualitatively. Findings: Injuries most often involved the back and knees (18% each). At least 47% of the injuries were work related. Injuries interfered with Soldiers' abilities to perform military tasks such as road marching (80%) and organized physical training (69%). Although many respondents indicated they were not experiencing pain, at least some Soldiers reported mild pain for each of 19 anatomic locations. Severe pain was reported most often for the lower back (21%). In their written comments, Soldiers expressed a sense of frustration with their injuries, the healthcare system and providers, and their unit leaders. Conclusions: Healthcare personnel are challenged to better manage Soldiers with musculoskeletal injuries and expedite their return to full duty. Unit leaders are challenged to create work environments that focus on injury prevention and allow injured Soldiers time to heal. Clinical Relevance: The Soldiers in this study were often engaged in physically challenging work or sports activities when injured. Because people outside the Army engage in similar activities (e.g., construction workers, endurance athletes), the findings from this study might be applicable to nonmilitary communities. Additionally, with the number of Reserve and National Guard Soldiers currently on active duty, civilian nurses might be caring for Soldiers with musculoskeletal injuries. [source]

Antioxidant Requirements of Endurance Athletes: Implications for Health

Inspiratory muscle performance in endurance athletes and sedentary subjects

RESPIROLOGY, Issue 2 2001
Peter R. Eastwood
Objective: The aim of this study was to determine whether whole-body endurance training is associated with increased respiratory muscle strength and endurance. Methodology: Respiratory muscle strength (maximum inspiratory pressure (PImax)) and endurance (progressive threshold loading of the inspiratory muscles) were measured in six marathon runners and six sedentary subjects. Results: PImax was similar between the two groups of subjects but the maximum threshold pressure achieved was greater in marathon runners (90 ± 8 vs 78 ± 10% of PImax, respectively, mean ± SD, P < 0.05). During progressive threshold loading, marathon runners breathed with lower frequency, higher tidal volume, and longer inspiratory and expiratory time. At maximum threshold pressure, marathon runners had lower arterial O2 saturation, but perceived effort (Borg scale) was maximal in both groups. Efficiency of the respiratory muscles was similar in both groups being 2.0 ± 1.7% and 2.3 ± 1.8% for marathon runners and sedentary subjects, respectively. Conclusions: The apparent increase in respiratory muscle endurance of athletes was a consequence of a difference in the breathing pattern adopted during loaded breathing rather than respiratory muscle strength or efficiency. This implies that sensory rather than respiratory muscle conditioning may be an important mechanism by which whole-body endurance is increased. [source]

Effects of hypoxia on diaphragmatic fatigue in highly trained athletes

THE JOURNAL OF PHYSIOLOGY, Issue 1 2007
Ioannis Vogiatzis
Previous work suggests that exercise-induced arterial hypoxaemia (EIAH), causing only moderate arterial oxygen desaturation (: 92 ± 1%), does not exaggerate diaphragmatic fatigue exhibited by highly trained endurance athletes. Since changes in arterial O2 tension have a significant effect on the rate of development of locomotor muscle fatigue during strenuous exercise, the present study investigated whether hypoxia superimposed on EIAH exacerbates the exercise-induced diaphragmatic fatigue in these athletes. Eight trained cyclists (: 67.0 ± 2.6 ml kg,1 min,1; mean ±s.e.m.) completed in balanced order four 5 min exercise tests leading to different levels of end-exercise (64 ± 2, 83 ± 1, 91 ± 1 and 96 ± 1%) via variations in inspired O2 fraction (: 0.13, 0.17, 0.21 and 0.26, respectively). Measurements were made at corresponding intensities (65 ± 3, 80 ± 3, 85 ± 3 and 90 ± 3% of normoxic maximal work rate, respectively) in order to produce the same tidal volume, breathing frequency and respiratory muscle load at each . The mean pressure time product of the diaphragm did not differ across the four exercise tests and ranged between 312 ± 28 and 382 ± 22 cmH2O s min,1. Ten minutes into recovery, twitch transdiaphragmatic pressure (Pdi,tw) determined by bilateral phrenic nerve stimulation, was significantly (P= 0.0001) reduced after all tests. After both hypoxic tests (: 0.13, 0.17) the degree of fall in Pdi,tw (by 26.9 ± 2.7 and 27.4 ± 2.6%, respectively) was significantly greater (P < 0.05) than after the normoxic test (by 20.1 ± 3.4%). The greater amount of diaphragmatic fatigue in hypoxia at lower leg work rates (presumably requiring smaller leg blood flow compared with normoxia at higher leg work rates), suggests that when ventilatory muscle load is similar between normoxia and hypoxia, hypoxia exaggerates diaphragmatic fatigue in spite of potentially greater respiratory muscle blood flow availability. [source]

RESTING METABOLIC RATE AND POST-PRANDIAL THERMOGENESIS BY LEVEL OF AEROBIC POWER IN OLDER ATHLETES

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2004
Alessio Sullo
SUMMARY 1.,The aim of the present study was to evaluate the resting metabolic rate (RMR) and thermogenic effect of a meal (TEM) in older athletes. 2.,Eighteen older male volunteers were divided into three groups according to their aerobic power related to fat-free mass (FFM) as follows: (i) group I, high aerobic power (Vo2max > 70 mL/kg FFM per min); (ii) group II, moderate aerobic power (Vo2max = 55,70 mL/kg FFM per min); and (iii) group III, low aerobic power (Vo2max < 55 mL/kg FFM per min). 3.,The RMR values, covariated for FFM using analysis of covariance (ancova), were higher in group I (mean (±SEM) 1.09 ± 0.04 kcal/min) than in groups II and III (0.99 ± 0.05 and 0.91 ± 0.03 kcal/min, respectively). Group I had a tendency for higher mean TEM values compared with the other groups, but the differences were not statistically significant for absolute or percentage values. 4.,Master endurance athletes with high aerobic power exhibit a higher RMR than master endurance athletes of similar age and body composition but with lower aerobic power. [source]

Adaptative or maladaptative hypertrophy, different spatial distribution of myocardial contraction

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2010
Francesco Cappelli
Summary Background:, Left ventricular hypertrophy (LVH) may be an adaptative remodelling process induced by physical training, or result from pathological stimuli. We hypothesized that different LVH aetiology could lead to dissimilar spatial distribution left ventricular (LV) contraction, and compared different components of LV contraction using 2-dimensional (2-D) speckle tracking derived strain in subjects with adaptative hypertrophy (endurance athletes), maladaptative hypertrophy (hypertensive patients) and healthy controls. Method:, We enrolled 22 patients with essential hypertension, 50 endurance athletes and 24 healthy controls. All subjects underwent traditional echocardiography and 2-D strain evaluation of LV longitudinal, circumferential and radial function. LV basal and apical rotation and their net difference, defined as LV torsion, were evaluated. Results:, LV wall thicknesses, LV mass and left atrium diameter were comparable between hypertensive group and athletes. LV longitudinal strain was reduced only in hypertensive patients (P < 0·05). LV apex circumferential strain was higher in hypertensive patients than in other groups (P < 0·001), LV basal circumferential strain, although slightly increased, did not reach significant difference. Hypertensive patients showed significantly increased rotation and torsion (P < 0·001), while no differences were observed between athletes and control. Conclusion:, In patients with pathological LVH, LV longitudinal strain was reduced, while circumferential deformation and torsion were increased. No differences were observed in LV contractile function between subjects with adaptative LVH and controls. In pathological LVH, increasing torsion could be considered a compensatory mechanism to counterbalance contraction and relaxation abnormalities to maintain a normal LV output. [source]

Left ventricular end-diastolic geometrical adjustments during exercise in endurance athletes

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 2 2008
Egil Henriksen
Summary The increase in left ventricular (LV) end-diastolic volume has recently been shown to explain more than 70% of the increase in stroke volume during upright exercise in endurance athletes. As the end-diastolic volume enhancement not could be explained by an increase in axial cavity length an augmentation in LV short-axis diameters is to be expected. To investigate LV end-diastolic geometrical alterations during exercise, 15 endurance athletes were examined using contrast exercise echocardiography. LV end-diastolic short-axis diameters were made from apical views at several LV cavity levels. From upright rest to upright exercise the LV end-diastolic internal cavity measurements increased significantly. During exercise, the LV cavity became geometrically more spherical with the largest increase in the LV end-diastolic short-axis cavity diameters in the mid and apical parts of the left ventricle. The LV internal long axis showed significant increase from rest to exercise but the absolute increase was small. [source]