Resistance training (RT) is a popular method of conditioning to enhance sport 
performance as well as an effective form of exercise to attenuate the 
age-mediated decline in muscle strength and mass. Although the benefits of RT on 
skeletal muscle morphology and function are well established, its effect on left 
ventricular (LV) morphology remains equivocal. Some investigations have found 
that RT is associated with an obligatory increase in LV wall thickness and mass 
with minimal alteration in LV internal cavity dimension, an effect called 
concentric hypertrophy. However, others report that short- (<5 years) to 
long-term (>18 years) RT does not alter LV morphology, arguing that concentric 
hypertrophy is not an obligatory adaptation secondary to this form of exertion. 
This disparity between studies on whether RT consistently results in cardiac 
hypertrophy could be caused by: (i) acute cardiopulmonary mechanisms that 
minimise the increase in transmural pressure (i.e. ventricular pressure minus 
intrathoracic pressure) and LV wall stress during exercise; (ii) the underlying 
use of anabolic steroids by the athletes; or (iii) the specific type of RT 
performed. We propose that when LV geometry is altered after RT, the pattern is 
usually concentric hypertrophy in Olympic weightlifters. However, the pattern of 
eccentric hypertrophy (increased LV mass secondary to an increase in diastolic 
internal cavity dimension and wall thickness) is not uncommon in bodybuilders. 
Of particular interest, nearly 40% of all RT athletes have normal LV geometry, 
and these athletes are typically powerlifters. RT athletes who use anabolic 
steroids have been shown to have significantly higher LV mass compared with 
drug-free sport-matched athletes. This brief review will sort out some of the 
factors that may affect the acute and chronic outcome of RT on LV morphology. In 
addition, a conceptual framework is offered to help explain why cardiac 
hypertrophy is not always found in RT athletes.