WARNING: Do not attempt these techniques yourself without consulting a doctor. You could injure yourself or worse. Bad things could happen to you. You might even die.
Do you know your maximum heart rate? I recently started to wear my Polar heart rate monitor again and wanted to know my max heart rate (MHR). After a quick internet search, I learned that the most commonly used formula is 220 minus your age. If this is true, my MHR should be around 172 beats per minute. (OK, so now you know how old I am if you are any good at math.) My target aerobic zone should be between 120-145 bpm.
I set out on a few runs with this knowledge and noticed right off that I was training beyond my target zone; my rate was usually in the 150-170 range. On a recent Run El Paso Club run, I ran at my max HR for over one and a half hours while carrying on a conversation the entire time. Is my MHR really 172?
After a more thorough internet search, I discovered that the only way to really know your MHR is to push yourself until you experience “fibrillations”. One article gave the instructions to basically find a good hill and run up it as fast as you can until you fall down. (read here) OK, that sounds like a reasonable test to me, so I set out to try it.