"From there, you need to take your heart rate as high as you can and maintain that one number on your heart rate monitor that you can sustain without increasing or decreasing your heart rate for 20 minutes."-koffee

This may sound naive, but how do you know you can sustain such an elevated heart rate for 20 minutes? I know if my legs are burning and I'm out of breath I go into protection mode and slow down and recover so to ensure I can go the distance. I guess I don't understand how you sustain such a challenge and then repeat it.

"The way you know you've reached anaerobic intensity is by going by rate of perceived exertion. The feeling you'll have is that you'll be out of breath and soreness and pain in the legs (from lactic acid accumulation)." - koffee


I'm also confused by the word 'perceived'. I know the reason I want a heart rate monitor is to challenge myself physically. I feel that I am too kind to my body. I am very aware of a physical goal and want to finish and not burnout. So, I pace myself...sometimes I think my fear of burnout costs me speed and improvement. What my mind perceives as exhaustion seems very different than what my body perceives as exhaustion. I think my mind is very kind. Does this make sense? So, how do you truly know you are at the desired point to sustain a 20 minute pace? I guess this is why I'd only every do these tests with the supervision of a professional.

This is a very informative thread...thanks!