When you think of core work, crunches, sit ups, and planks may come to mind. However, one big function of the midsection is to prevent movement. A bicep curl is a great example. As the weight gets away from your body, during the middle of the movement, you have to use more muscles to keep the spine and hips aligned. Think of this next time you do the movement, and go lighter or less reps if you can’t control it. Also-never curl in the squat rack!