Midsection Shred is a core and cardio workout that goes after the midsection the way it actually gets built: not with crunches, but with a heart rate that stays honest while the core holds everything together. High knees, plank holds and plank jump-ins - three exercises that alternate between running in place and bracing on the floor, so the abs work both as movers and as anchors within the same set.

The circuit runs without rest between exercises, and the design is a conversation between two positions. Three blocks of 20 high knees supply the cardio - every knee driven to hip height is a rep for the hip flexors and lower abs as much as the legs - while two 20-count plank holds and two pairs of plank jump-ins supply the bracing. The alternation is the shredding mechanism: high knees demand the core stabilize a moving torso at speed, then the plank holds demand it stabilize a static one under load, then the jump-ins ask for both at once - an explosive hip flexion performed from a braced plank. Cycling between dynamic and isometric core work keeps the midsection under some form of tension for the entire set, and the elevated heart rate does the quiet caloric bookkeeping the workout's name is promising.

Drive high knees to hip height with a tall torso - leaning back to lift the knees higher is a rep that flatters and lies. In the plank holds, stack hands under shoulders and keep one straight line from head to heels for the full 20-count. On plank jump-ins, jump the feet forward to land under the hips with control, then jump back to a full, locked-out plank before the next rep counts.

The shred doesn't happen in one heroic set. It happens because the core never got a set off - and today, it didn't.

Make it Harder: Double the plank jump-ins to 4 per block.

Make it Easier: March the high knees and take the plank holds from your knees.