Key points from article :
Study analysed hearts of people aged 45-64 with no history of exercising regularly.
Progressive aerobic exercise over the two years saw improvement in heart health.
Maximum oxygen intake improved, as did plasticity in the left ventricular muscle.
Result was a reversal of decades of a sedentary lifestyle on the heart.
Benefits not seen in people taking yoga and weight training.
Heart appears to retain ability to remodel itself up to the age of 65.
The study was published in Circulation journal.
