aerobic

http://www.yourrunning.com/blog-half_a_minute_faster

I still don't know how this works, but after 3 weeks of easy running, I turned up for our second sub-5 miling assessment time trial and saw a massive improvement.

The object of the day (after warm-up and drills) is to run the same distance at the same heart rate -- 80% of heart rate reserve, or around 153 bpm for me -- as we did three weeks ago. Back then I ran it at 8:00 per mile pace, or even a bit slower; today I ran at 7:30 pace for the same effort. This stuff works!

http://www.yourrunning.com/forum-metronome_training#comment-4303

Q: When training, is it best to learn to run at a pace using a metronome? Or is it more important to use a heart monitor and focus on aerobic vs. anaerobic?

Simon says:
You can't learn the fine art of pace judgement using a metronome. What you can use it for is to check and, if you need to, to improve your cadence -- your footstrikes per minute.