Vascular and cardiac remodeling in world class professional cyclists

Exercise Training Duration and Intensity Are Associated With Thicker Carotid Intima-Media Thickness but Improved Arterial Elasticity in Active Children and Adolescents

Even though exercise generally has a positive effect on health, intensive exercise can have adverse effects on the vascular system of adults. This study aimed to investigate the association between training duration and intensity and vascular structure and function in 427 physically active children and adolescents (14.0 ± 1.94 years). In this study, we examined carotid intima-media thickness (cIMT), carotid diameter, and cIMT:diameter-ratio as parameters of carotid arterial structure and arterial compliance (AC), stiffness index β (β), elastic modulus (Ep), and carotid pulse wave velocity (PWVβ) as parameters of carotid arterial function with high-resolution ultrasound. We collected central systolic blood pressure (cSBP) and aortic pulse wave velocity (aPWV) as parameters of central arterial stiffness with an oscillometric device. We used the MoMo Physical Activity Questionnaire to record training duration and intensity. Training duration (p = 0.022) and intensity (p = 0.024) were associated with higher cIMT. Further, training duration was associated with lower central arterial stiffness (cSBP: p = 0.001; aPWV: p = 0.033) and improved AC (p < 0.001). Higher training intensity was related to improved AC (p < 0.001) and larger carotid diameter (p = 0.040). Boys presented thicker cIMT (p = 0.010), improved AC (p = 0.006), and lower central arterial stiffness (cSBP: p < 0.001; aPWV: p = 0.016) associated with higher training duration. Girls presented improved AC (p = 0.023) and lower Ep (p = 0.038) but higher β (p = 0.036) associated with higher training duration. Only boys demonstrated thicker cIMT (p = 0.016) and improved AC (p = 0.002) associated with higher training intensity. A quintile analyses of the training duration revealed thicker cIMT of children and adolescents in Q1 and Q5 than that in Q4 and Q5. Besides, Q1 showed lower cSBP compared to Q4 and Q5. Regarding training intensity, Q5 had thicker cIMT than Q2 and Q3. Although a higher training load is associated with thicker cIMT, the common carotid artery is also more elastic. This suggests that a higher training load leads to a functional adaptation of the carotid artery in youth.

Arterial Function after a 246 km Ultra-marathon Running Race

There is little research about the effects of ultra-endurance exercise on arterial morphological and functional properties. The aim was to assess the acute changes of the carotid-femoral pulse wave velocity and carotid doppler-derived parameters following an ultra-marathon race as well as the intima-media thickness of the carotid artery in ultra-marathon runners. Twenty athletes were examined at baseline and within 10 mins after a 246 km running race. Measurements included carotid-femoral pulse wave velocity, peak-systolic and end-diastolic velocities of carotid artery blood flow, pulsatility and resistivity indices and blood biochemical parameters. The intima-media thickness of the right and left carotid artery was measured before the race. Arterial stiffness and carotid artery intima media thickness at rest remained within known normal limits. The ultra-marathon race significantly increased carotid-femoral pulse wave velocity by 22.6% and pulsatility index by 10.2%. There was a decrease in body weight by 3.35% and an increase of all biochemical markers of muscle damage after the race. Additionally, C-reactive protein was correlated with both pulsatility and resistivity indices post-race. This study shows that immediately after a 246 km ultra-marathon running race, acute increase of arterial stiffness and vascular resistance were evident. The carotid artery thickness of ultra-marathon runners was within normal range.

Impact of endurance exercise on the heart of cyclists: A systematic review and meta-analysis

OBJECTIVE

To compare heart structure and function in endurance athletes relative to participants of other sports and non-athletic controls in units relative to body size. A secondary objective was to assess the association between endurance cycling and cardiac abnormalities.

PATIENTS AND METHODS

Five electronic databases (CINAHL, Cochrane Library, Medline, Scopus, and SPORTdiscus) were searched from the earliest record to 14 December 2019 to identify studies investigating cardiovascular structure and function in cyclists. Of the 4865 unique articles identified, 70 met inclusion criteria and of these, 22 articles presented 10 cardiovascular parameters in units relative to body size for meta-analysis and five presented data relating to incidence of cardiac abnormalities. Qualitative analysis was performed on remaining data. The overall quality of evidence was assessed using GRADE. Odds ratios were calculated to compare the incidence of cardiac abnormality.

RESULTS

Heart structure was significantly larger in cyclists compared to non-athletic controls for left ventricular: mass; end-diastolic volume, interventricular septal diameter and internal diameter; posterior wall thickness, and end-systolic internal diameter. Compared to high static and high dynamic sports (e.g., kayaking and canoeing), low-to-moderate static and moderate-to-high dynamic sports (e.g., running and swimming) and moderate-to-high static and low-to-moderate dynamic sports (e.g., bodybuilding and wrestling), endurance cyclists end-diastolic left ventricular internal diameter was consistently larger (mean difference 1.2-3.2 mm/m²). Cardiac abnormalities were higher in cyclists compared to controls (odds ratio: 1.5, 95%CI 1.2-1.8), but the types of cardiac abnormalities in cyclists were not different to other athletes.

CONCLUSION

Endurance cycling is associated with a larger heart relative to body size and an increased incidence of cardiac abnormalities relative to controls.

Influence of Vigorous Physical Activity on Structure and Function of the Cardiovascular System in Young Athletes-The MuCAYA-Study

Objective: Moderate physical activity (PA) is associated with a reduced risk to develop cardiovascular disease. However, junior athletes exercise between 10 and 20 h a week with intensities exceeding moderate levels by far. In this regard, the cardiovascular system has to increase its work five to six times compared to moderate intensities. This may result in potentially pathological adaptations of the cardiovascular system. The underlying process of vascular adaptations to exercise is yet not fully understood and hardly investigated in junior athletes. An increased blood pressure and pulse wave velocity, ventricular hypertrophy, arrhythmia, and even sudden cardiac death (SCD) has been reported in adult athletes. Studies, examining the cardiovascular system in children, its association to intensity and type of exercise, are rare. Therefore, we present the study protocol of a prospective cross-sectional study that investigates the influence of PA on the cardiovascular system in young athletes.

Methods and Design: Children and adolescents, 7–18 years, presenting for their annual pre-participation screening at the Institute of Preventive Pediatrics, Faculty of Sports and Health Sciences, Technical University of Munich (TUM), are examined in this prospective cross-sectional study. Vascular parameters measured by ultrasound are carotid intima-media thickness (cIMT), vascular stiffness (AC, Ep, β, PWV β), and the vascular diameter (D) to calculate the IMT:Diameter-Ratio (IDR). Cardiac function is evaluated by a 12-lead ECG, and echocardiographic parameters (end-diastolic left ventricular diameter, left ventricular diastolic posterior wall thickness, diastolic septal thickness, left ventricular mass and relative wall thickness, ejection fraction, and shortening fraction). A cardiopulmonary exercise test is performed on a bicycle ergometer, muscular strength is assessed with the handgrip test, and physical activity with the MoMo questionnaire.

Discussion: It is essential to follow young athletes over the course of their career in order to detect pathophysiological changes in the myocardium as soon as possible. If these changes are preceded or followed by changes in vascular structure and function is not known yet. Therefore, we present the study protocol of the Munich Cardiovascular adaptations in young athletes study (MuCAYA-Study) which investigates the association between vascular and cardiac adaptation to intensive exercise in junior athletes.

Arterial adaptations in athletes of dynamic and static sports disciplines - a pilot study

BACKGROUND

Structural and functional arterial adaptations with regard to the type and level of training in young athletes are understudied. Our research aimed at evaluating them in two types of exercise (dynamic and static) and two levels of engagement (high and recreational).

METHODS

A total of 76 volunteers formed five groups. Group A included 17 high-level dynamic sports athletes 30·9 ± 6·4 years old, group B 14 recreational ones aged 28·7 ± 6·2 years, group C 15 high-level static sports athletes 26·4 ± 3·9 years old and group D 16 recreational ones, aged 25·8 ± 4·8 years. Fourteen sedentary men 30 ± 3·8 years old formed control group E. Structural indices of left cardiac chambers and thoracic aorta were echographically obtained, as well as common carotid intima-media thickness (cIMT). Furthermore, applanation tonometry was conducted, at rest and during a handgrip strength test, for the acquisition of central arterial pressure parameters, carotid-femoral pulse wave velocity (cfPWV) and total arterial compliance (C_τ ).

RESULTS

No significant differences in structural arterial markers were observed. However, group A obtained the highest handgrip central systolic pressure values (13·1% compared to group D, P<0·05). Resting cfPWV was lower in group B by 13·8% (P<0·05) than C and by 16·7% (P<0·01) than E, whereas C_τ was higher in group Β by 33·3% than C (P<0·05) and by 40·9% than E (P<0·01).

CONCLUSION

Functional arterial exercise-induced adaptations become apparent at an early age, without being in conjunction with structural ones. Recreational dynamic exercise results in the most favourable arterial characteristics.

Changes of intima-media thickness in marathon runners: A mid-term follow-up

Objective Carotid intima-media thickness (IMT) is used to assess cardiovascular risk and progression of atherosclerosis. It is known that regular physical activity of moderate intensity has beneficial effects on the vasculature. However, it is still discussed controversially whether prolonged exercise, including participation in exhaustive competitive sports such as long-distance races, has also beneficial effects or might even be harmful regarding the cardiovascular system. Patients and methods Thirty-eight male marathon runners (45.8 ± 7.3 years) were investigated twice (2009 and 2013) for their carotid IMT (using ultrasound techniques), anthropometrics and clinical chemistry. Additionally, training volume (running kilometres per year) and competition participation (half marathon, marathon and ultramarathon) within this follow-up period were assessed. Results During 3.8 ± 0.4 years of follow-up, runners performed 1587 (850-2500) training kilometres per year and participated in a total of 7 (4-12) long distance competitions. IMT increased in total by 0.05 ± 0.09 mm or annually by 0.013 ± 0.023 mm, respectively. Higher increase in IMT over that period was associated with higher fasting blood glucose (beta = .355, p = .045) at baseline examination. Effects of training volume and number of competitions on the progression of IMT could not be demonstrated in our longitudinal analysis. Conclusions Higher blood glucose levels are associated with detrimental effects on vasculature in otherwise healthy male marathon runners. Regular marathon training, including competition participation over at least several years, was not associated with detrimental effects on IMT or, vice versa, seems not to provide beneficial effects on vasculature.

Mortality of French participants in the Tour de France (1947-2012)

AIMS

In the context of recent concerns regarding performance enhancing techniques and potential negative health effects of high-level physical activity, data on the long-term outcomes and causes of death in elite endurance cyclists are of particular interest.

METHODS AND RESULTS

Characteristics and vital status of all French participants in the Tour de France were collected for the 1947-2012 period. Causes of death were obtained from 1968. Overall and disease-specific mortalities were compared with the French male population using overall and specific standardized mortality ratios (SMRs) with their 95% confidence intervals (CIs). Among the 786 French cyclists who participated at least once between 1947 and 2012, 208 (26%) died by 1 September 2012. Neoplasms and cardiovascular diseases accounted for 61% of deaths. We observed a 41% lower mortality in French cyclists (SMR: 0.59, 95% CI: 0.51-0.68, P < 0.0001), which did not change over time (P = 0.70). It was observed for main mortality causes: for neoplasms (SMR: 0.56; 95% CI: 0.42-0.72, P < 0.0001) and for cardiovascular death (SMR: 0.67; 95% CI: 0.50-0.88, P = 0.004), except mortality related to external causes (SMR: 1.06, 95% CI: 0.71-1.53, P = 0.80).

CONCLUSION

We observed a substantially and significantly lower mortality in participants in the Tour de France, compared with the general male population. However, our results do not allow us to assess in detail the balance between positive effects of high-level sports activity and selection of healthy elite athletes, vs. any potential deleterious effects of excessive physical exercise or alleged doping.

A prospective randomized longitudinal study involving 6 months of endurance or resistance exercise. Conduit artery adaptation in humans

Abstract  This randomized trial evaluated the impact of different exercise training modalities on the function and size of conduit arteries in healthy volunteers. Young (27 ± 5 years) healthy male subjects were randomized to undertake 6 months of either endurance training (ET; n = 10) or resistance training (RT; n = 13). High-resolution ultrasound was used to determine brachial, femoral and carotid artery diameter and wall thickness (IMT) and femoral and brachial flow-mediated dilatation (FMD) and glyceryl trinitrate (GTN)-mediated dilatation. Improvements in peak oxygen uptake occurred with ET (from 3.6 ± 0.7 to 3.8 ± 0.6 l min(-1), P = 0.024) but not RT. Upper body muscular strength increased following RT (from 57.8 ± 17.7 to 69.0 ± 19.5 kg, P < 0.001), but not ET. Both groups exhibited increases in lean body mass (ET, 1.4 ± 1.8 kg and RT, 2.3 ± 1.3 kg, P < 0.05). Resistance training increased brachial artery resting diameter (from 3.8 ± 0.5 to 4.1 ± 0.4 mm, P < 0.05), peak FMD diameter (+0.2 ± 0.2 mm, P < 0.05) and GTN-mediated diameter (+0.3 ± 0.3 mm, P < 0.01), as well as brachial FMD (from 5.1 ± 2.2 to 7.0 ± 3.9%, P < 0.05). No improvements in any brachial parameters were observed following ET. Conversely, ET increased femoral artery resting diameter (from 6.2 ± 0.7 to 6.4 ± 0.6 mm, P < 0.05), peak FMD diameter (+0.4 ± 0.4 mm, P < 0.05) and GTN-induced diameter (+0.3 ± 0.3 mm, P < 0.05), as well as femoral FMD-to-GTN ratio (from 0.6 ± 0.3 to 1.1 ± 0.8, P < 0.05). Resistance training did not induce changes in femoral artery parameters. Carotid artery IMT decreased in response to both forms of training. These findings indicate that 6 months of supervised exercise training induced changes in brachial and femoral artery size and function and decreased carotid artery IMT. These impacts of both RT and ET would be expected to translate to decreased cardiovascular risk.

Cardiac magnetic resonance assessment of left and right ventricular morphologic and functional adaptations in professional soccer players

BACKGROUND

Professional, long-term physical training is associated with cardiac morphologic and functional changes that depend on the type of exercise performed. So far, the specific effect of soccer training on cardiac morphology has not been investigated with cardiac magnetic resonance imaging (CMRI). We sought to use CMRI to study left ventricular (LV) and right ventricular (RV) morphologic and functional adaptations in professional soccer players.

METHODS

Twenty-nine male professional soccer players (mean age 24.6 +/- 3.9 years, range 18-31 years) in different playing positions and 29 nonathlete male controls (27.0 +/- 3.7 years, 21-34 years) underwent CMRI. Electrocardiographic-gated steady-state free-precession cine CMRI was used to measure myocardial mass (MM), end-diastolic volume (EDV) and end-systolic volume, stroke volume (SV), ejection fraction, and cardiac index at rest. We calculated the ventricular remodeling index (RI) to describe the pattern of cardiac hypertrophy.

RESULTS

Ventricular volume and mass indices were significantly (P < .001) higher in athletes. LVEDV and RVEDV on MRI was above normal in 27/29 athletes. There was a strong positive correlation between EDV and myocardial mass (P < .01). The LVRI and RVRI were similar (0.73 +/- 0.1 g/mL; 0.22 +/- 0.01 g/mL) to that of controls (0.71 +/- 0.1 g/mL; 0.22 +/- 0.01 g/mL). No significant differences were observed for LV ejection fraction and cardiac index. Neither the comparison of athletes in different playing positions nor the comparison of younger and older players revealed statistically significant differences.

CONCLUSION

Cardiac magnetic resonance imaging measurements enable studying the mechanisms of LV and RV adaptation in professional soccer players and reflect the ventricular response to combined endurance and strength based training.

Echocardiographic characteristics of professional tennis players at the Roland Garros French Open

BACKGROUND

Intensive sport may induce cardiac modifications. No recent study has been performed in elite tennis players. The aim of this cross-sectional study was to analyze the cardiac characteristics in a population of professional tennis players.

METHODS

During the 2004 French Open Tennis Tournament, we offered complete echocardiographic screening to all professional tennis players. The study population consisted of 160 subjects: 80 tennis players (50 men and 30 women) and age- and sex-matched control groups (n = 80).

RESULTS

Indexed left ventricular mass was significantly higher in tennis players (P < .0001). Left ventricular hypertrophy was present in 18 male (36%) and 6 female (20%) tennis players versus 2 men (4%) and no woman in the control groups (P < .0001 and P = .02, respectively). All indexed right and left atrial measurements were significantly higher in tennis players (P < .003). The incidence of left and right atrial dilation was significantly higher in tennis players (P < or = .0001). Indexed right atrial area and left atrial volume were significantly higher in baseline players as compared with offensive players and to control groups (P < .0001), whereas there was no significant difference in left ventricular mass according to the style of play (P > .75). No significant between-group difference was observed in Doppler data.

CONCLUSIONS

In the present study, professional tennis players presented significant cardiac differences, as compared to a control group, with moderate left ventricular hypertrophy, bilateral atrial dilation, and normal systolic and diastolic functions. Atrial dilation is related to the style of play (baseline or offensive) and should be considered as physiological in tennis players.

Non-traumatic lower limb vascular complications in endurance athletes. Review of literature

OBJECTIVES

To review the importance, clinical features, investigations, management and prognosis of non-traumatic vascular injuries, affecting the lower limbs of endurance athletes.

DESIGN

Review of literature.

MATERIALS AND METHODS

A literature search was conducted from Medline, Pubmed, the National Electronic Library for Health, Google and Yahoo search engines for related articles and case reports regarding non-traumatic vascular complications involving the lower limb of endurance athletes.

CONCLUSIONS

Non-traumatic vascular complications affecting the lower limbs include endofibrosis, stenosis/kinking of iliac arteries, dissection of external iliac artery, adductor canal syndrome, popliteal entrapment syndrome, chronic exertional compartment syndrome and effort-induced venous thrombosis. These are important as they affect athletes at the peak of their career and can be confusing to diagnose. The management is relatively well documented and produces good results in short term but the long term results are not known.

Serial left ventricular adaptations in world-class professional cyclists

OBJECTIVES

The purpose of this research was to study long-term left ventricular (LV) adaptations in very-high-level endurance athletes.

BACKGROUND

Knowledge of cardiac changes in athletes, who are at particularly high risk of sudden cardiac death, is mandatory to detect hypertrophic cardiomyopathy (HCM) or dilated (DCM) cardiomyopathy.

METHODS

We carried out echocardiographic examinations on 286 cyclists (group A) and 52 matched sedentary volunteers (group C); 148 cyclists participated in the 1995 "Tour de France" race (group A1), 138 in the 1998 race (group A2), and 37 in both (group B).

RESULTS

In groups A, A1, A2, and C, respectively, diastolic left ventricular diameter (LVID) was 60.1 +/- 3.9 mm, 59.2 +/- 3.8 mm, 61.0 +/- 3.9 mm, and 49.0 +/- 4.3 mm (A vs. C and A1 vs. A2, p < 0.0001), and maximal wall thickness (WT) was 11.1 +/- 1.3 mm, 11.6 +/- 1.3 mm, 10.6 +/- 1.1 mm, and 8.6 +/- 1.0 mm (A vs. C and A1 vs. A2, p < 0.0001). Among group A, 147 (51.4%) had LVID >60 mm; 17 of them had also a below normal (<52%) left ventricular ejection fraction (LVEF). Wall thickness exceeded 13 mm in 25 athletes (8.7%) (always <15 mm), 23 with LVID >55 mm. In group B, LVID increased (58.3 +/- 4.8 mm to 60.3 +/- 4.2 mm, p < 0.001) and WT decreased (11.8 +/- 1.2 mm to 10.8 +/- 1.2 mm, p < 0.001) with time.

CONCLUSIONS

Over one-half of these athletes exhibited unusual LV dilation, along with a reduced LVEF in 11.6% (17 of 147), compatible with the diagnosis of DCM. Increased WT was less common (always <15 mm) and scarce without LV dilation (<1%), eliminating the diagnosis of HCM. Serial examinations showed evidence of further LV dilation along with wall thinning. These results might have important implications for screening in athletes.

Left ventricular hypertrophy differences in male professional runners and in young patients suffering from mild hypertension

AIMS

This study was executed to evaluate left ventricular (LV) geometry, diastolic and systolic function assessed by B- and M-mode and pulsed Doppler echocardiography in a group of professional sprinter runners (group I), in young patients suffering from mild hypertension (group II) and in control young adults (group III). Twenty-one male sprinter runners were checked during a period of training and compared with 19 young patients suffering from mild hypertension and 15 healthy controls matched for gender and body size.

FINDINGS

LV septum thickness, LV posterior wall thickness, LV ejection fraction, LV shortening fraction, midwall fractional shortening and stroke volume were significantly higher in runners compared to hypertensive patients and controls (p < 0.001). A significant increase of diastolic function parameters of the early peak flow velocity, E, and the early/late diastolic wave ratio, E/A, and in the isovolumic relaxation time or in the E velocity deceleration time wave was observed in hypertensive patients when compared to runners and controls (p < 0.05). The study of the pulmonary venous flow revealed a significant increase in the early systolic flow velocity, S, in hypertensive patients compared to runners (p < 0.05); the late diastolic flow velocity, D, appeared to be similar in all groups, while atrial backward flow velocity, Ar, was higher in group I and II respect to control (p < 0.001).

CONCLUSIONS

Our data indicate that LV concentric hypertrophy in sportsmen is associated with improvement of systolic and diastolic performance, whereas diastolic dysfunction can occurs even in the early stages of hypertension in young patients, in whom an alteration in the LV filling appears even in absence of systolic dysfunction and evident concentric myocardial hypertrophy.

The Tour de France: a physiological review

On 5 July 2003, the Tour de France (TDF) has celebrated 100th running. Instead of a chimney sweep competing during his free time (as in 1903), the recent winner is a highly trained, professional cyclist whose entire life-style has been dedicated to reach his pinnacle during this event. The TDF has been held successfully for 100 years, but the application of the physiologic sciences to the sport is a relatively recent phenomenon. Although some historical reports help to understand the unique physiological characteristics of this race, scientific studies were not available in Sports Science/Applied Physiology journals until the 1990s. The aim of this article is to review the history of the TDF. Special emphasis is placed on the last decade where classic physiology has been integrated into applied scientific cycling data.

Size and blood flow of central and peripheral arteries in highly trained able-bodied and disabled athletes

In a cross-sectional study, central and peripheral arteries were investigated noninvasively in high-performance athletes and in untrained subjects. The diastolic inner vessel diameter (D) of the thoracic and abdominal aorta, the subclavian artery (Sub), and common femoral artery (Fem) were determined by duplex sonography in 18 able-bodied professional tennis players, 34 able-bodied elite road cyclist athletes, 26 athletes with paraplegia, 17 below-knee amputated athletes, and 30 able-bodied, untrained subjects. The vessel cross-sectional areas (CSA) were set in relation to body surface area (BSA), and the cross-section index (CS-index = CSA/BSA) was calculated. Volumetric blood flow was determined in Sub and Fem via a pulsed-wave Doppler system and was set in relation to heart rate to calculate the stroke flow. A significantly increased D of Sub was found in the racket arm of able-bodied tennis players compared with the opposite arm (19%). Fem of able-bodied road cyclist athletes and of the intact limb in below-knee amputated athletes showed similar increases. D of Fem was lower in athletes with paraplegia (37%) and in below-knee amputated athletes proximal to the lesion (21%) compared with able-bodied, untrained subjects; CS-indexes were reduced 57 and 31%, respectively. Athletes with paraplegia demonstrated a larger D (19%) and a larger CS-index in Sub (54%) than able-bodied, untrained subjects. No significant differences in D and CS-indexes of the thoracic and abdominal aorta were found between any of the groups. The changes measured in Sub and Fem were associated with corresponding alterations in blood flow and stroke flow in all groups. The study suggests that the size and blood flow volume of the proximal limb arteries are adjusted to the metabolic needs of the corresponding extremity musculature and underscore the impact of exercise training or disuse on the structure and the function of the arterial system.

Transmitral and pulmonary venous flow study in elite male runners and young adults

BACKGROUND

Even if diastolic function has been assessed in athletes by analysis of transmitral Doppler flow, no one has studied pulmonary venous flow in this population. The aim of this study was to establish if the physiological adaptations following a prolonged physical training could influence the diastolic function in a professional Olympic male runner group.

METHODS

From February to December 1999 we studied 25 athletes (Group I) during the period of maximal training compared with 18 age- and sex-matched healthy sedentary subjects (Group II). We used mono- and bidimensional Echocardiography to assess left ventricular structure and systolic function. The diastolic function was evaluated by Doppler method assessing transmitral and venous pulmonary flow.

RESULTS

From the comparison between the two groups, we found great differences in the interventricular septum and the posterior wall thickness; the analysis of the systolic function demonstrated a significant increase in ejection fraction, stroke volume, left ventricular mass, and end diastolic volume in the athletes' population. Fluximetric study showed that ventricular diastolic function is not influenced by hypertrophy: indeed, Doppler evaluation of the transmitral flow showed a bigger velocity of the E wave, similarly, when we assessed pulmonary venous flow, we found faster retrograde Ar wave in group I.

CONCLUSIONS

Our data indicate that diastolic function remains normal or improves in some cases after physical training; left ventricular hypertrophy and concentric remodeling do not involve diastolic changes like hypertrophic and hypertensive heart diseases.

Ethnic differences in carotid and left ventricular hypertrophy

OBJECTIVES

Afro-Caribbean subjects have a higher prevalence of hypertension, a lower prevalence of ischaemic heart disease and a higher premature mortality compared to White Europeans. Left ventricular hypertrophy (LVH) is also more prevalent in Afro-Caribbeans even at similar levels of blood pressure. It is widely believed that carotid artery intima-media thickening (IMT) represents an early marker for the development of atheroma, and carotid IMT and LVH are associated in White populations. Whether the relationship between carotid IMT and LVH is similar in Black subjects is unknown.

METHODS

Thirty-eight subjects were studied using carotid and femoral ultrasonography and echocardiography; 19 Afro-Caribbean and 19 White European subjects were matched for age, sex and mean 24 h systolic blood pressure.

RESULTS

The Afro-Caribbean group had a significantly greater left ventricular mass index (LVMI) compared to the White European: 136.4 +/- 6.1 versus 112.4 +/- 6.2 g/m2, P < 0.01. However, carotid IMT, carotid diameter, femoral IMT and femoral diameter were similar between the groups: 0.75 +/- 0.02 versus 0.77 +/- 0.04 mm, 6.54 +/- 0.15 versus 6.56 +/- 0.16 mm, 0.66 +/- 0.03 versus 0.68 +/- 0.03 mm and 8.40 +/- 0.33 versus 8.25 +/- 0.23 mm, respectively.

CONCLUSIONS

Afro-Caribbean subjects with similar blood pressures have similar mean carotid and femoral IMTs compared to White Europeans, in spite of marked differences in LVMI. Whether this reflects a discrepancy in the degree of cardiovascular risk for similar levels of LVMI or whether this is a reflection of an altered pattern of target organ damage associated with hypertension in Afro-Caribbean subjects is unclear.

Physiology of professional road cycling

Professional road cycling is an extreme endurance sport. Approximately 30000 to 35000 km are cycled each year in training and competition and some races, such as the Tour de France last 21 days (approximately 100 hours of competition) during which professional cyclists (PC) must cover >3500 km. In some phases of such a demanding sport, on the other hand, exercise intensity is surprisingly high, since PC must complete prolonged periods of exercise (i.e. time trials, high mountain ascents) at high percentages (approximately 90%) of maximal oxygen uptake (VO2max) [above the anaerobic threshold (AT)]. Although numerous studies have analysed the physiological responses of elite, amateur level road cyclists during the last 2 decades, their findings might not be directly extrapolated to professional cycling. Several studies have recently shown that PC exhibit some remarkable physiological responses and adaptations such as: an efficient respiratory system (i.e. lack of 'tachypnoeic shift' at high exercise intensities); a considerable reliance on fat metabolism even at high power outputs; or several neuromuscular adaptations (i.e. a great resistance to fatigue of slow motor units). This article extensively reviews the different responses and adaptations (cardiopulmonary system, metabolism, neuromuscular factors or endocrine system) to this sport. A special emphasis is placed on the evaluation of performance both in the laboratory (i.e. the controversial Conconi test, distinction between climbing and time trial ability, etc.) and during actual competitions such as the Tour de France.

Effect of blood pressure and physical activity on carotid artery intima-media thickness in stage 1 hypertensives and controls

The aim of the study was to investigate whether hypertension and physical training induce parallel changes in the arterial wall. Ninety-seven never-treated stage 1 hypertensive patients (HT) (systolic blood pressure 140 to 159 mm Hg or diastolic blood pressure 90 to 99 mm Hg) aged 18 to 45 years taking part in the Hypertension and Ambulatory Recording Venetia Study and 27 normotensive volunteers (NT) aged 30 +/- 9 years were studied. Data on physical or sports activity were collected and scored, and target organ involvement was investigated by assessing microalbuminuria, echocardiography, and carotid ultrasound study. The carotid arteries were examined according to the Atherosclerosis Risk in Communities protocol. Mean (m-IMT) and maximal (M-IMT) carotid intima-media thickness were measured at end-diastole in the far wall common carotid artery, in the bulb and internal carotid artery, in the lateral and posterior projection, averaging the left and right sides. A comparable level of physical activity was present in HT patients and NT subjects. Twenty-four-hour blood pressure and blood lipid levels, as well as target organ damage, were similar in physically active and sedentary HT. The m-IMT of the common carotid was greater in sedentary HT than in sedentary NT, as well as in active than in sedentary NT. The m-IMT of the internal carotid artery was also greater in active HT than in active NT, as well as in active than in sedentary HT. In logistic regression, comparing the first and fourth quartile of m-IMT, scored physical activity was a predictor of m-IMT in the internal carotid artery. No statistical interaction was found between physical activity and hypertension, indicating that these two items have a cumulative effect and act independently of each other. Sedentary HT had significantly greater levels of M-IMT than sedentary NT in all sites but the bulbs; in the internal and common carotid arteries, HT exercisers had significantly greater M-IMT than NT exercisers. Therefore, physical activity appears to be an early independent predictor of carotid wall thickness. This factor should be taken into consideration in population-based studies aimed at investigating supraortic vessels as it can act as a confounder.

Arterial properties of the carotid and femoral artery in endurance-trained and paraplegic subjects

In humans, the relationships of blood flow changes to structure, function, and shear rate of conducting arteries have not been thoroughly examined. Therefore, the purpose of this study was to investigate these parameters of the elastic-type, common carotid artery (CCA) and the muscular-type, common femoral artery (CFA) in long-term highly active and extremely inactive individuals, assuming that the impact of activity-induced blood flow changes on conduit arteries, if any, should be seen in these subjects. We examined 21 highly endurance-trained athletes (A), 10 paraplegic subjects (P), and 20 sedentary subjects (S) by means of noninvasive ultrasound. As a result, the CFA diameter and compliance were highest in A (9.7+/-0.81 mm; 1.84 +/-0.54 mm(2)/kPa) and lowest in P (5.9+/-0.7 mm; 0.54+/-0.27 mm(2)/kPa) compared with S (8.3+/-1.0 mm; 0.92+/-0.48 mm(2)/kPa) with P <0.01 among the groups. Both parameters correlated with each other (r = 0.62; P<0.01). Compared with A (378+/-84 s(-1); 37+/-15 s(-1)) and S (356+/-113 s(-1); 36+/-20 s(-1)), the peak and mean shear rates of the CFA were almost or more than doubled in P (588+/-120 s(-1); 89+/-26 s(-1)). In the CCA, only the compliance and peak shear rate showed significant differences among the groups (A: 1.28+/-0.47 mm(2)/kPa, 660+/-138 s(-1); S: 1.04+/-0.27 mm(2)/kPa, 588+/-109 s(-1); P: 0.65+/- 0.22 mm(2)/kPa, 490+/-149 s(-1); P<0.05). In conclusion, the results suggest a structural and functional adaptation in the CFA and a predominantly functional adaptation of the arterial wall properties to differences in the physical activity level and associated exercise-induced blood flow changes in the CCA. The results for humans confirm those from animal experiments. Similar shear rate values of S and P in the CFA support the hypothesis of constant shear stress regulation due to local blood flow changes in humans. On the other hand, the increased shear rate in the CFA in P indicates an at least partially nonphysiological response of the arterial wall in long-term chronic sympathectomy due to a change in local blood flow.