What Is The Mechanism That Causes The Drop Of The Maximal Heart Rate During Normal Aging?
Gahlul S, Hofmann P, Morris G and Hoffmeister M
Published on: 2021-05-29
Aging reduces exercise capacity because of a general decline of body functions including the functions of the cardiovascular system. A major change is an age-dependent near linear decrease of maximal heart rate (HRmax).
In this narrative review, we highlight putative mechanisms causing the age-related decline in the HRmax.
The exact molecular mechanisms causing HRmax to decline with normal aging are unknown. Possible mechanisms responsible for the functional changes in the aging heart are:
- Anatomical and structural changes,
- Electrophysiological changes such as a decline in intrinsic heart rate and beta-adrenergic responsiveness and
- Changes in the rate of gene expression in human cardiac tissue. All these contribute to the age-dependent reduction of HRmax and consequently the decrease of the aerobic power (VO2max). Regular exercise is suggested to affect at least some of the prescribed influences on the age-related HRmax
Cardio-respiratory fitness, an important predictor of morbidity and mortality declines with normal aging partly due to the decline of the HRmax. However, the molecular mechanisms are unknown and to date there is no intervention with the potential to reverse this age-related decline in HRmax. Possible effects of exercise training are suggested but need to be proven.