Add intervals of intensity for a stronger heart
When it comes to exercise, interval training offers the best of both worlds.
When faced with an arduous physical task, most people break up the work with short periods of rest. Piano movers alternate bursts of heavy lifting with rest breaks; people with severe heart failure stop every now and then when climbing stairs. Giving stressed muscles time to recover lets them work harder and longer. The same thing holds true for conditioning the heart. For people with various forms of heart disease, an exercise plan that alternates bursts of intense activity with periods of rest or gentler activity seems to be better than longer stretches of continuous activity.