Strengthening your core muscles not only improves your posture, but it also makes it easier to carry out your most challenging workout routines. Dancers, gymnasts and other athletes do a number of exercises to strengthen and tone up their core muscles - the obliques, abdominals and lower back - because it helps them maintain balance and allows them to shift and control their body weight easily.

Strong core muscles will also reduce the risk of back pain and injury when you're working out. So how do you go about strengthening and toning that midriff? You'll need to start with a set of simple floor exercises that will train your muscles to move in a certain way.

You can begin with some simple oblique stretches and ab-lengthening exercises. Lie flat on your back with your toes pointed forward, then slowly raise each leg for a count of five, then lower it. Do the same with the other leg, and make sure you inhale on the lift and exhale as you lower the leg. Do the same movement with both legs to warm up the lower abdominal muscles, then slowly move your legs to the left or to the right to warm up the obliques.

Another great midriff-strengthening exercise is the standing twist. Here, you can hold two light weights at your side and lift your arms to shoulder length. The next step is to twist to the left, then the right in a fluid motion, all while keeping your abs tucked in. You won't feel a burn until you do several twists, but it's a simple and effective exercise for training your core muscles.

Finally, enhance the effects of your average floor-based crunch movement by focusing on keeping your shoulder blades off the floor, and not doing a complete sit up. Sit ups don't work if you have weak abdominal muscles. You need to focus on contracting the abdominals and obliques, then holding them in place for several seconds in an isolation move.

Don't think you have time to strengthen your core? Just grab your yoga mat and yoga gear during a commercial break and squeeze in some posture-enhancing stretches and crunches to tighten that midriff. Just a few quick spurts of intensive activity is all it really takes to help train those core muscles and start seeing results!