I got the chance to ask a panel of experts from the Cleveland clinic a question that has been bothering me -- and I got back what I think is a wonderfully clear answer. So, for what it's worth, I wanted to share it with the 50+'rs...
Dr. Blackburn is the Director of Cardiac Rehabilitation, Preventive Cardiology at the Cleveland Clinic.
This was from a public chat and the transcripts are available online -- so I don't think I'm violating any copyright or privacy laws by posting this here...
GeorgeBMac: Hi, Everyone "knows" that exercise is good for the heart and the vascular system -- but why is AEROBIC exercise good for that system? Physiologically, what does it do that is good for the cardio/cerebral vascular system?
Gordon Blackburn PhD: Exercise and improvement in functional capacity have a strong impact in reducing risk for developing heart disease, in both the primary and secondary settings, and reducing mortality. For every 1 MET increase in functional capacity there is a 9 – 12 percent reduction in cardiovascular and all cause death. (Exercise intensity can be described in units of METS. 1 MET=1 kcal/kg body wt/hr).
Some of the direct effects of exercise include improved endothelial function (protective lining of the artery); increased capillary density; improved blood pressure control; improved glucose control; and slight improvement in HDL. All of these directly and indirectly decrease the risk of developing and progressing heart disease.
For myself, it drives me nuts when hear "it's good for you!" -- but there is no clear reason given for saying that. It sounds too much like my mom telling me to eat my veges... So, for the first time I think I have a better understanding of what cycling does for me. Thank you Dr. Blackburn!