This 2-day a week core program is based off a 2019 research study that was published in the Journal of Sports Science Medicine. The research looked at the efficacy of foam rolling and a core strengthening program on different athletic and health outcomes. The results from the original program, based on 2 weekly sessions for 8-weeks, concluded the following: 1. Eight weeks of core-stability training two times per week improved dorsal trunk strength with no changes in a foam rolling group or the control. 2. Hamstring flexibility was improved both by an eight-week core-strength and foam rolling training intervention. In this Jefit core program, the first four-weeks use less intensity and overall time and includes 5-6 core exercises. In weeks 5-8, the focus is on similar core movements with longer old times, slight progressions and about a 2-minute longer workout session.. It is up to you to increase the duration of the exercises as you deem fit. Make sure you rest 24-48 hours between day 1 and day 2 sessions. Stay Strong Together, MICHAEL WOOD, CSCS Jefit