According to my treadmill, I work out in the Anaerobic Zone. I run 3 to 4 miles in this zone with a significant incline (5-6.5) and it takes between 28-38 minutes.
My question is - is that long enough to reach my 'anaerobic threshold' and thus am I burning mostly glucose? Or do I need a longer workout to reach that level?
Assuming your treadmill has been accurately calibrated (most likely it has not), I'd say no to your question. Though I'm unsure how much that incline would affect things, the pace is considerably slower than AT pace.
Take a look at your treadmill again. I've never seen a treadmill that says "anaerobic zone". I've seen lots with HR charts that list "Aerobic Zone" or "Fat Burning Zone". I've seen some that list "High Intensity" or something like that. They really don't mean anything and are very vague. The ranges they list are very wide. All of those charts should be erased from the treadmill.
My question to you is....How do you feel after this run? Don't let the treadmill tell you how you should feel. If you run a high intensity run for 28-38 minutes you are going to be dead tired, breathing hard, sweating hard. What are you trying to do? What are you training for? If you're training for a local 5k then running hard for 28-38 minutes straight you might not be running fast enough. It is a good over-distance endurance run though. My suggestion, if you are training for a local 5k, would be run run hard for that amount of time or a little longer, let's say 20 minutes. Run faster than you did on this 28-38 min run.
Train according to what you plan to race, not what something says on a treadmill.
Alan
bump.
Why do these machines have such silly labels as "hard core zone" on them? All it does is serve to confuse people. What exactly IS the "Hard core Zone" anyways.
I would like to find it. And always be in it. I love being hard core.
I am training for a 5K. I have been running 3-4 miles a few days a week for the past couple of years. During the winter (I'm in Michigan) I run on the treadmill, and during the Spring/Summer/Fall I usually run outdoors.
So I am looking into figuring out the best way for me to train for this 5K run...my first race ever. And also just curious what kind of training is needed to reach my anaerobic threshold.
Anaerobic threshold training has but a small part in 5K preparation. You would be better advised to be doing aerobic capacity workouts twice a week (intervals at 100% vVO2max). A bump in your mileage is advised also. Good luck.