DVD-Based High Intensity Interval Exercise vs. Moderate Continuous Exercise: Which Type is More Beneficial to Overall Fitness?

Abstract

High intensity interval training (HIIT) has previously been shown to increase physical fitness to a greater extent than continuous moderate intensity exercise performed for the same or greater duration. However, most studies of HIIT have utilized stationary bicycles for training. This study examined HIIT using the DVD-based program “Insanity”. Participants volunteered to be in either the Insanity group (n=9) or a control group (n=7). The Insanity group completed the DVD exercise for 30 minutes, 3 times/week, while the control group completed 30 minutes of continuous moderate intensity cardiovascular activity 2 times per week along with 30 minutes of strength training 1 time per week. VO2 max, body fat percentage, vertical jump, timed push-ups and sit ups were assessed prior to and following 5.5 weeks of training. Following training there were no differences between the groups for VO2 max, body composition or sit ups. There was a trend for improved vertical jumps in both groups (Insanity pre: 22.17±1.17, post: 23.2±1.3 inches; Control pre: 17.5±1.33, post: 17.64±1.46 inches. p=0.08). There was also a significant improvement in both groups for the push-up test (Insanity pre: 44.67±15.54, post: 58.22±17.28; Control pre: 31.0±14.8, post: 37.71±12.24. p=0.000) with the Insanity group showing a greater increase in response to training compared to the control group (p=0.05). Although there were not many differences between groups, positive trends in the results suggest it is possible that a longer duration of study may yield more significant results