That's why we spoke with a fitness pro who outlines a stellar seven-day core strength challenge for a flatter stomach ... 3 sets of 15 reps per side. Sit on the floor with your knees bent and ...
That's why we spoke with a fitness pro who outlines a stellar seven-day core strength challenge for a flatter stomach ... 3 sets of 15 reps per side. Sit on the floor with your knees bent and ...