Cardiovascular studies on former endurance athletes

Occurrence of chronic disease in former top-level athletes. Predominance of benefits, risks or selection effects?

Former elite athletes from most sports disciplines have lower overall morbidity risk and enjoy better self-rated health in later years compared with the general population and matched controls who were healthy at young age. This is seen particularly among former endurance athletes who have a lower incidence of coronary heart disease and type 2 diabetes mellitus. Most often data are available only for men. Based on the available data, participation in elite sports cannot be regarded as an overall health hazard. However, aside from a high risk of acute injury in specific sports, possible negative effects of long-standing athletic activity on the development of osteoarthritis should not be neglected. It should also be remembered that elite athletes are a biologically and genetically select group who are not representative of the population at large. Given the nature of the available data, the possible health consequences of recent changes in different characteristics of sports, such as training practices, professionalism and use of doping, cannot be properly predicted.

Factors affecting levels of physical activity in adults

A large proportion of adults in Western cultures are physically inactive, despite several decades of warnings about the potentially negative health consequences of a sedentary lifestyle. Efforts to promote physical activity have focused on identifying its determinants and designing interventions that might effectively promote regular physical activity. The multitude of factors that induce adults to initiate and maintain programmes of physical activity have been divided into those that are invariable (age, gender, race, ethnicity) and those that are presumed to be modifiable (behavioural and personality characteristics, environmental circumstances and community settings). The lack of consistency in the design, analysis and reporting of interventions in the lives of inactive or sedentary individuals has produced equivocal results. However, several social and environmental factors have systematically emerged as determinants of physical activity in adults. In ethnic minorities, the removal of barriers such as unaffordable facilities and unavailable childcare, high crime rates, fear for personal safety and culturally inappropriate activities are of primary importance. Social support from family, peers, communities and healthcare providers has resulted in modest improvements across cultures, ages and genders in selected settings, but the definition of specific interventions and their outcomes deserve additional attention. Longitudinal studies indicate that components of physical fitness are relatively transitory, with low to modest correlations between physical activity and measures of physical fitness in childhood and adolescence and in adulthood. Attempts to explain the activity behaviour of adults by applying various theories in programmes of intervention have also produced mixed results. Successful interventions tailor programmes to individual needs, account for personal levels of fitness, allow for personal control of the activity and its outcomes, and provide for social support by family, peers and communities. The initiation and maintenance of regular physical activity in adults depends on a multitude of biological and sociocultural variables that demand attention across the lifespan.

Coronary heart disease risk factors in middle-aged former top-level athletes

A cross-sectional study was conducted to determine the impact of previous athleticism on coronary heart disease (CHD) risk factors in 168 middle-aged men and 147 middle-aged women in Estonia. Participants were divided into four groups: physically active ex-athletes (AA), sedentary ex-athletes (SA), recreational exercisers (RE), and non-exercisers (NE). The Sharkey's questionnaire was applied to determine the CHD risk factors, health habits, medical, safety, personal, psychological and women's risk factors scores. Anthropometric characteristics, resting systolic and diastolic blood pressure values (SBP, DBP), and physical working capacity (PWC170) were measured. Concentrations of total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), triacylglycerols (TG), and glucose were determined. Low-density lipoprotein cholesterol (LDL-C) and HDL-C/CHOL ratio were computed. From the questionnaire results, significant differences in CHD risk scores in both sex groups in favour of AA and RE were found. DBP in men was significantly higher in SA, and SBP in women was significantly higher in NE in comparison with other groups. PWC170 and PWC170/kg was highest in AA and lowest in NE in both sex groups. There were no significant differences for blood biochemical parameters between women's groups. In men, AA had a lower CHOL level in comparison with SA and NE, and lower concentrations of TG and LDL-C than other groups. AA and RE had a higher HDL-C concentration and HDL-C/CHOL ratio in comparison with the other groups. In conclusion, differences in CHD risk factors were related to current physical activity, and were more expressed in men than in women.

Physical activity and its relationship to blood pressure in school children

The present report analyzes the relationship between physical activity and blood pressure in 1341 school children aged 7-14 years (girls = 598, boys = 743) participating in a screening for cardiovascular risk factors that took place in the suburban area of Naples. During the baseline examination, systolic (SBP) and diastolic (DBP) blood pressure, height, weight, and resting pulse rate (PR) were measured. The Harvard-Modified Step Test was also performed in order to score both a crude recovery index (RI) and an index corrected for the initial resting pulse rate (RI-PR) used as measures of the level of habitual physical activity. Significant differences have been found between the quartiles of distribution of both the crude recovery index and the corrected index in girls and boys with regard to systolic blood pressure but not diastolic. In both sexes, better responders to the Harvard-Modified Step Test showed on the average lower systolic blood pressure than poorer responders. In boys, the inverse association between systolic blood pressure and the recovery index was independent of the effect of age, body mass index, height, and resting pulse rate, while in girls the same association did not reach statistical significance. Our results support the hypothesis that systolic blood pressure is independently related to the level of habitual physical activity in children.

Effects of physical deconditioning after intense endurance training on left ventricular dimensions and stroke volume

To determine the role of preload in maintaining the enhanced stroke volume of upright exercise-trained endurance athletes after deconditioning, six highly trained subjects undergoing upright and supine bicycle ergometry were characterized before and after 3, 8 and 12 weeks of inactivity that reduced oxygen uptake by 20%. During exercise, oxygen uptake, cardiac output by carbon dioxide rebreathing, cardiac dimensions by M-mode echocardiography, indirect arterial blood pressure and heart rate were studied simultaneously. Two months of inactivity resulted in a reduction in stroke volume, calculated as cardiac output/heart rate, during upright exercise (p less than 0.005) without a significant change during supine exercise. A concomitant decrease in the left ventricular end-diastolic dimension from the trained to the deconditioned state was observed in the upright posture (5.1 +/- 0.3 versus 4.6 +/- 0.3 cm; p = 0.02) but not with recumbency (5.4 +/- 0.2 versus 5.1 +/- 0.3 cm; p = NS). There was a strong correlation between left ventricular end-diastolic dimension and stroke volume (r greater than 0.80) in all subjects. No significant changes in percent fractional shortening or left ventricular end-systolic dimension occurred in either position after cessation of training. Estimated left ventricular mass was 20% lower after 3 and 8 weeks of inactivity than when the subjects were conditioned (p less than 0.05 for both). Thus, the endurance-trained state for upright exercise is associated with a greater stroke volume during upright exercise because of augmented preload. Despite many years of intense training, inactivity for only a few weeks results in loss of this adaptation in conjunction with regression of left ventricular hypertrophy.

Muscle strength and body composition as determinants of blood pressure in young men

The correlations of blood pressure to various indices of muscularity and fatness were studied in 183 young healthy men (mean age 19.7, SD 2.1 years). Systolic pressure showed significant positive correlations with body fat percentage, isometric strength of trunk extensors, body mass index, lean body mass, strength of leg extensors, heart rate, and the sum of four skinfolds. Diastolic pressure had significant positive correlations with body mass index, lean body mass, body fat percentage, sum of skinfolds, strength of leg extensors, strength of trunk extensors, and age. A stepwise selective multiple regression analysis for systolic pressure resulted in four significantly correlating variables: body fat percentage (p less than 0.001), heart rate (p less than 0.01), lean body mass (p less than 0.05), and strength of trunk extensors per kg body weight (p less than 0.05). For diastolic pressure the analysis resulted in two explaining variables: body mass index (p less than 0.001) and age (p less than 0.05). In a regression equation with 13 variables the strength of trunk flexors was negatively correlated with diastolic pressure. It is concluded that both fatness and muscularity are factors related to blood pressure in young men. The muscularity effect is more clearly associated with trunk and leg extensor strength.

The athlete's heart syndrome: a new perspective

Although earlier electrocardiographic and roentgenographic studies suggested that the heart of trained athletes differed from that of nonathletes, little was known of the cardiac dimensions of the athlete's heart until the advent of echocardiography. Echocardiographic studies have demonstrated that trained athletes may have increased left ventricular mass and that the structural change accounting for this increase is related to the type of physical conditioning. Athletes participating primarily in isotonic exercise have an increase in left ventricular end-diastolic volume with little or no increase in left ventricular wall thickness whereas those athletes participating primarily in isometric exercise have an increase in left ventricular wall thickness associated with normal left ventricular end-diastolic volume. Comparisons between echocardiographically determined cardiac changes in college and world class athletes were made, and the electrocardiographic and chest roentgenographic changes present in the athlete's heart syndrome were reviewed.

Noninvasive evaluation of ventricular hypertrophy in professional athletes

Athletes often exhibit ECG findings which are considered to be abnormal. Therefore, we used noninvasive graphic methods to study 42 active professional male basketball players, ranging in age from 21 to 31 years, without clinically evident heart disease. Of the 42, 11 (25%) met the Romhilt-Estes ECG voltage criteria for left ventricular hypertrophy, and 12 (29%) satisfied VCG criteria for left ventricular enlargement; nine (21%) had left ventricular hypertrophy by both methods. In 33 subjects (79%) the 0.04 sec vector in the horizontal plane was anterior, and 29 of these exhibited one or more standard criteria for right ventricular enlargement; the ECG and VCG were concordant for right ventricular hypertrophy in 16 subjects (38%). Submaximal treadmill exercise tests (Bruce protocol) were normal in eight athletes, while in one subject ventricular premature beats occurred during the test. In 24 of 25 athletes (96%) from whom phonocardiograms were obtained a third heart sound was recorded, while in 14 (56%), a fourth heart sound was present. Of the 14 athletes who had a fourth heart sound, 12 (86%) had either ECG or VCG evidence of ventricular hypertrophy. Only four of 23 athletes had an increased cardiothoracic ratio (greater than .50) on routine chest X-ray. Ten athletes and ten control subjects matched for height, weight and body surface area had echocardiograms satisfactory for analysis. The left ventricular end-diastolic dimension in the athletes averaged 53.7 +/- 1.3 (SE) mm compared with a value of 49.9 +/- 0.7 mm in the control subjects (P less than 0.02), and was increased (greater than or equal to 56 mm) in four. Left ventricular posterior wall thickness averaged 11.1 +/- 0.6 mm, compared with a value of 9.8 +/- 0.5 mm in the control subjects (P less than 0.05), and was increased (greater than or equal to 11 mm) in six athletes. The right ventricular end-diastolic dimension averaged 20.8 +/- 1.1 mm compared with a value of 12.9 +/- 2.2 mm in the controls (P less than 0.004), and was increased (greater than or equal to 23 mm) in four athletes. No athlete or control subject exhibited paradoxical septal motion. In the athletes, ejection fraction (cube method) averaged 79 +/- 2.0% and mean Vcf averaged 1.13 +/- 0.04 circ/sec; these values did not differ from those of the control subjects. Thus, both right and left ventricular enlargement ("physiological hypertrophy") are often present in the well-trained athlete, but left ventricular performance remains normal in the basal state in such individuals. We condlude that these individuals represent a selected subgroup of subjects who are variants of normal.