Recently (2007) Helgerud, Hoydale, et. al reported that higher intensity training (90% Heart Rate Max) significantly increased their VO2 max compared to other training methods. This means that for fit individuals looking to improve their maximal oxygen capacity, trade in the long slow distance running for a workout that consists of short bursts of high intensity running (90% of Heart Rate Max) with three minutes of active low intensity work (i.e. walking, jogging at 70% of Heart Rate Max). The subjects in this study participated in the High Intensity Interval training three training sessions per week for a period of eight weeks. If you're a fit individual looking for an added challenge to take your cardio fitness to the next level... give this workout a try.