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

Abstract

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.

Physiological Society Symposium – the Athlete's Heart

“…Athletes participating in purely resistance sports such as power lifting, wrestling and judo are subject to large increases in cardiac afterload, which results in an increase in LVWT to normalise wall tension but without much increase in left ventricular cavity size. Echocardiographic studies evaluating athletes either participating in purely isotonic (endurance) or isometric (resistance) events confirm this theory (Morganroth et al 1975;Longhurst et al 1980;Telford et al 1988). However, most sporting disciplines involve a combination of endurance and resistance training, therefore the majority of athletes show increases in both LVWT and left ventricular cavity size.…”

“…However, there have been a small number of studies in younger athletes which suggest that age has an effect on cardiac adaptation to regular intensive physical training. Most studies confined to prepubertal athletes (Hollmann et al 1986;Gutin et al 1988;Telford et al 1988;Rowland et al 1994) have either attempted to study cardiac adaptation in young athletes or to test the hypothesis that children who excel in sport may be preselected due to their greater cardiac dimensions. These studies show no evidence for preselection and indicate only modest clinical evidence of 'athlete's heart' in prepubertal athletes compared with adult athletes.…”

Cardiac dimensions, physical activity, and submaximal working capacity in youth of the Québec Family Study

“…The results are consistent with those of Ricci et al (1982), who noted no signi®cant changes in cardiac dimensions following 8 weeks of endurance, sprint, or strength training. Telford et al (1988) reported no differences in cardiac dimensions between moderately trained and untrained 11-to 12-year-old children who were matched for skeletal age and estimated fat-free mass. Among the 9-to 12-year-old boys investigated in the present study, there was a low, but signi®cant association between estimated EE and ST (r=0.28) and LVM (r=0.24).…”

“…However, 9-to 12-year-old boys at the extremes of estimated EE and MVPA did not dier signi®cantly in echocardiographic dimensions (Tables 4 and 5). 1.8*** 6.9 1.5 9.9 2.2*** 6.5 1.8 11.1 2.1*** 7.5 1.8 *P<0.05 Statistically signi®cant between genders within age groups; **P<0.01 statistically signi®cant between genders within age groups; ***P<0.001 statistically signi®cant between genders within age groups Several authors have speculated about a``critical threshold'' of exercise intensity that may exist for inducing cardiac enlargement (Janz et al 1996;Savage et al 1990;Telford et al 1988). This has previously been hypothesized by Maron (1986), but no studies have examined the in¯uence of various exercise intensities on the development of cardiac enlargement.…”

“…Although the results of some studies indicate that cardiac dimensions are greater in young athletes than in non-athletes (Allen et al 1977;Hollman and Bouchard 1970;Medved et al 1986), others have not found such dierences (Rowland et al 1994;Telford et al 1988). The results of short-term (2±8 months) endurance training programs have demonstrated either increases (Geenan et al 1982) or no signi®cant changes (Ekblom 1967;Ricci et al 1982) in cardiac dimensions in younger subjects.…”