Crunches are a powerful core workout that hold many benefits and work out rectus abdominis and external obliques like no other! But some people make mistakes that can seriously mess with their results. Here are the top 3, and how to fix them! 1) You hold your breath. Depriving your body of oxygen during any exercise is very unhealthy. Jacquelyn Brennan, collegiate trainer and registered kinesiologist, recommends exhaling on the way up. This breathing technique will make you automatically inhale on the way down. It will also deeply target your core muscles. 2) You relax going down. Giving your body a break on the way down won't give you all the benefits of this workout, as you're only doing half the work! Squeeze your abs as you lower yourself, and ease your way down. This will work your core harder. 3) You crunch too high. Remember, these aren't sit-ups! Keep your focus on bringing your ribs to your belly button and raising your chest a few inches off the ground. Getting those killer abs is as easy as implementing that one simple movement! What are your tips for getting a hard hitting core workout? Share them with us in the comments below!