Unaltered left ventricular mechanics and remodelling after 12 weeks of resistance exercise training – a longitudinal study in men

Previous longitudinal studies suggest that left ventricular (LV) structure is unaltered with resistance exercise training (RT) in young men. However, evidence from aerobic exercise training suggests that early changes in functional LV wall mechanics may occur prior to and independently of changes in LV size, although short-term changes in LV mechanics and structural remodelling in response to RT protocols have not been reported. Therefore, the purpose of this study was to examine the effects of RT on LV mechanics in healthy men performing two different time-under-tension protocols. Forty recreationally-trained men (age: 23Âą3 years) were randomized into 12 weeks of whole-body higher-repetition RT (20-25 repetitions/set to failure at ~30-50% 1RM; n=13), lower-repetition RT (8-12 repetitions/set to failure at ~75-90% 1RM; n=13), or an active control period (n=14). Speckle tracking echocardiography was performed at baseline and following the intervention period. Neither RT program altered standard measures of LV volumes (end-diastolic volume, end-systolic volume, or ejection fraction; P>0.05) or indices of LV mechanics (total LV twist, untwisting rate, twist-to-shortening ratio, untwisting-to-twist ratio, or longitudinal strain; P>0.05). This is the first longitudinal study to assess both LV size and mechanics after RT in healthy men, suggesting a maintenance of LV size and twist mechanics despite peripheral muscle adaptations to the training programs. These results provide no evidence for adverse LV structural or functional remodelling in response to RT in young men and support the positive role of RT in the maintenance of optimal cardiovascular function, even with strenuous RT.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author