This intermediate program is an offshoot from my previously published Core Focused (Big 6 @Gym) workout that you should check out too. This is a 2-day bodyweight only, core program, which can be done at home or basically anywhere. One of the sessions is interval based only. The idea is to get as many repetitions (using good form) in the suggested interval time. The second session is more of your traditional-based core workout, where you will do sets/repetitions. Day 1: Includes 6 exercises, workout time is about 20-minutes in this interval session. There is also a superset that pairs mountain climbers with plank for 3 sets, using minimal recovery time between supersets. Day 2: Also has 6 exercises. This workout, however, is a longer session, at about 32-minutes, if you follow the suggested rest time between all sets that is. Stay Strong, MICHAEL WOOD, CSCS Jefit Team