I'm in a pretty standard base phase right now building up to indoor track, and im wondering how much an easy fast-paced workout will affect my condition. specifically, im interested in doing a marathon-type speed workout of 30 seconds hard, 30-60 seconds easy, alternating between 3k pace and recovery pace for a total of 3-5 miles. the goal is to accomplish a metabolic workout something like an easy tempo run by averaging 5:30-6:00 pace for the duration (depending on the intensity of the "on" segment), as well as a neurological stimulus by running ~2 miles total of "on" at around 3k to 5k pace.
will this get me "in shape" too quickly by acting like a VO2max workout metabolically? or is this a safe threshold-type workout that will improve my aerobic base as well?
any experience with this kind of workout is appreciated.