In the 1980s, Dr Ralph Paffenberger tracked the exercise habits of 16,936 men at Harvard University between 1916 and 1950 and found men who expended 2,000 calories or more a week through vigorous exercise, lived longer and had a 39% lower risk of heart disease than those who did not.
For each hour of physical activity, exercisers lived an extra two to three hours. |
 |
Benefits in life span and cardiovascular health
At the ESC Congress 2007 in Vienna, a Basic Science Track session will explore the molecular mechanisms whereby exercise may produce benefits in life span and cardiovascular health. The session will explore how changes in myocytes, skeletal muscles, endothelial cells and stem cell release contribute to the beneficial effects. By understanding the mechanisms, researchers hope to discover a switch that would be open to pharmacological manipulation. “But an additional advantage is that once we know the exact mechanism it’s likely to be easier to motivate people to exercise,” said Oyvind Ellingsen (Trondheim, Norway).
Aerobic exercise and arterial thickness
Douglas Seals (Boulder, USA) believes habitual aerobic exercise prevents the increased arterial thickness and impaired vascular endothelial function that can accompany ageing. Studies have shown that the greater the maximum oxygen intake (an indicator of the amount of exercise), the less stiff arteries are likely to be. Exercise may be associated with preserved basic nitric oxide production.
The enhanced functioning of cardiac myocytes that occurs in fit people secures pump function and protects against the possibility of lethal arrhythmias, says Ellingsen. He believes that beneficial changes in myocytes are mediated through activation of IGF-1/Akt and Cam Kinase signalling, resulting in improved calcium handling, which enables the myocardium to contract more vigorously.
Exercise significantly increased the activity of radical scavenger enzymes
Volker Adams (Leipzig, Germany) believes that exercise decreases the load of reactive oxygen species in muscle. His group randomised 23 heart failure patients to six months of exercise training or a sedentary life style and found that training significantly increased the activity of radical scavenger enzymes such as superoxide dismutase, catalase and glutathione peroxidase in muscle.
“Exercise is likely to decrease protein turnover in their bodies with a beneficial effect on ageing,” said Adams, adding that the effect occurred throughout the body and was likely to occur in heart muscle.
Finally, Viviane Conraads (Antwerp, Belgium) says regular exercise results in the release of endothelial progenitor cells from the bone marrow into the circulation, which probably repairs damaged endothelium and promotes new blood vessels.