One workout may provide immediate protection to heart

A new review published in JAMA Cardiology suggests a single workout can protect the heart from ischemia for up to several days.

This theory is based on the concept of ischemic preconditioning, which refers to “the observation in both animals and humans that brief periods of ischemia before prolonged occlusion reduce subsequent infarct size and/or the risk for harmful ventricular arrhythmias,” wrote Dick H. J. Thijssen, PhD, and colleagues.

Acute episodes of exercise are a form of this preconditioning, according to the authors.

“Exercise induces a cardioprotective preconditioning stimulus with early protection of the cardiovascular system for 2 to 3 hours and a more robust and longer period of protection that emerges after 24 hours and remains for several days,” they wrote. “Importantly, these associations are present on the first episode of exercise, with subsequent exercise sessions reactivating protective pathways and leading to ongoing beneficial effects with myocardial ischemia.”

It is widely accepted that a physically active lifestyle can reduce the risk of cardiovascular disease. However, this observation is generally attributed to exercise’s ability to reduce cardiovascular risk factors such as body mass, cholesterol levels, insulin levels and fat mass, among others.

Thijssen et al.’s analysis of animal and human studies suggests short exposures to exercise—which wouldn’t allow for meaningful changes in these risk factors—can still lead to temporary cardioprotective effects.

One way clinicians could apply this knowledge is by considering “prehabilitation” before cardiac interventions. In this scenario, a patient would participate in physical therapy before the intervention with the goal of reducing cardiovascular complications.

“Cardioprotection through exercise preconditioning is a facile, inexpensive, and potent therapy that deserves greater recognition and further resources to establish the optimal dose,” Thijssen and colleagues wrote. “Nonetheless, as is so often the case with the benefits of exercise, its prescription follows the cardinal rule: use it or lose it.”