Today I did my 3rd treadmill tabata since starting up cardio again a little under a month ago. Today I did my usual 5 min warm up, then put the treadmill to a 12% grade and ran 20 seconds on and 10 seconds off for 4 minutes. I did the first 2 minutes of the work set at a 12 mile an hour pace, the 2nd 2 minutes at an 11:45 pace. I felt like it was a struggle to keep that pace up, but I like pushing myself. Next Thursday I'll attempt the full 4 minute work set at an 11:45 pace.
Everything I've ever read says you can tell your getting in shape if your heart rate returns to normal after being elevated through exersion. My heart rate is lowering more quickly after cardio now, and also I'm not as out of breath when I'm training at olympic weightlifting. Progress baby. Progress.