Mechanisms of Exercise-Induced Cardiac Remodeling Differ Between Young and Aged Hearts

Emily E. Schmitt; Benjamin D. McNair; Sydney M. Polson; Ross F. Cook; Danielle R. Bruns

Disclosures

Exerc Sport Sci Rev. 2022;50(3):137-144. 

In This Article

Conclusions

Regular exercise training improves cardiovascular fitness, is undoubtedly protective against cardiovascular disease, and slows cardiac aging if initiated early in life. In the young heart, physiological hypertrophy and concomitant improved systolic and diastolic functions are well described. These adaptations to exercise training, however, are not mirrored in the aged heart (Figure 3). Although regular exercise improves cardiorespiratory fitness, slows cardiac aging, and lowers the risk for cardiovascular disease, in the setting of aging, exercise results in regression of LV mass, attenuation of fibrosis, and modest improvements in diastolic and systolic functions, which appear to be largely dictated by the intensity of and age at exercise initiation. Despite the significance of exercise as cardiovascular medicine, the mechanisms by which the young and aged hearts benefit from exercise training are far from clear. We suggest that elucidation of age-specific mechanisms for exercise-induced cardiac remodeling will facilitate the use of exercise as cardiac medicine for patients of all ages.

Figure 3.

Exercise-induced cardiac remodeling differs between young and aged hearts. The aged heart is hypertrophic and fibrotic compared with the young, with impaired systolic reserve and diastolic function. In response to exercise training, young hearts undergo hypertrophy with improvements in systolic and diastolic functions. Aged hearts do not undergo hypertrophic remodeling but demonstrate regression of fibrosis with minimal changes in cardiac function. Sex/gender, genetics, and factors such as exercise intensity, type, and age of initiation all likely contribute to the different mechanisms of exercise-induced cardiac remodeling in the young and old hearts. Elucidation of these age-specific mechanisms is warranted to facilitate the prescription of exercise as cardiovascular medicine.

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