Scientists claim the experimental drug can even strengthen weak hearts.
The pill is based on a protein called CT1(cardiotrophin 1) that tricks the heart into thinking it is being exercised by growing healthily and pumping more blood.
This replicates what happens during a workout, jog or cycle ride.
Tests found that CT1 also repairs heart damage and improves blood flow.
It is not clear at this early stage how often it would have to be taken to have the desired effect.
Professor Lynn Megeney of Ottawa University said: “When part of the heart dies the remaining muscles try to adapt by getting bigger. But this happens in a dysfunctional way and it doesn’t actually help the heart pump more blood. We found CT1 causes heart muscles to grow in a more healthy way and it also stimulates blood vessel growth in the heart.”