Early echocardiographic studies of left ventricular (LV) morphology and fun
ction focused on single discipline athletes, primarily endurance and streng
th trained. To date there are few studies examining multi-disciplinary trai
ned athletes. The present echocardiographic study examined LV morphology an
d function in 18 elite triathletes (swimming, cycling, and running) and 11
elite modern pentathletes (running, swimming, shooting, fencing, and show-l
umping) compared with age- and sex-matched controls. Elite triathletes demo
nstrated significantly (p < 0.05) increased LV wall thickness and cavity di
mensions together with LV mass, both in absolute terms and scaled for body
surface area, compared with controls. Elite modern pentathletes demonstrate
d significantly (p < 0.05) increased LV wall thickness with a non-significa
nt increase in LV internal diameter. Despite significant LV enlargement, th
e distribution of hypertrophy and diastolic filling indices were normal in
both triathletes and modern pentathletes and significantly increased in the
triathletes. It is concluded that multi-disciplinary training results in v
ariations in LV morphology. The inciting stimulus resulting in LV enlargeme
nt in triathletes is associated with prolonged endurance activity, together
with an isometric component accompanying cycling. In contrast, elite moder
n pentathletes experience a reduced endurance component combined with a hig
h isometric component associated with fencing.