Gene-environment interactions and the response to exercise

Many of the symptoms of heart failure (breathlessness and fatigue) are not primarily due to reduced cardiac output, but relate to an impairment of per ipheral muscle performance and metabolic efficiency. With regular training it is possible to increase skeletal muscle performance through improvements in muscle efficiency. Recent data suggest that such improvements may be mo dulated by local tissue renin-angiotensin systems and, in particular, by th e local activity of angiotensin-converting enzyme (ACE). These findings mig ht explain the remarkable benefits of ACE inhibition in the treatment of he art failure.