I don't think this is a healthy way to run. Plus it may work while you're young, but past 30 there's no way that you go on like this. Buy a heart rate monitor,

I don't think this is a healthy way to run. Plus it may work while you're young, but past 30 there's no way that you go on like this. Buy a heart rate monitor, and run at a reasonable speed for longer times, run faster once a week only to improve your performance and endurance.