Building a strong core does not mean doing the same few exercises over and over for a long period of time, it has to include variety to keep your muscles guessing what’s next. These next two exercises work on the obliques to trim your waistline and also the rectus abdominis, which are the muscles that we think about when hoping to get a six-pack.
Using a medium sized stability ball, place both feet on top of the ball. Make sure your core is tight and your back isn’t caving in in order to protect your back and be most effective for the abs. Keeping wrists, elbows and shoulders in alignment, extend your legs and come into a plank position. 
Bring your knees back under your hips and repeat 15-20 times for three sets. This exercise will focus mainly on your abs, and the secondary muscles worked include the hamstrings and shoulders. It should also challenge your balance, as we know that strength to balance comes from the core muscles.
Side planks are common, but don’t forget to add variation, like this tree pose. Start in a regular side plank with feet stacked over each other, wrist, elbow and shoulder should create a straight line to provide the most stability and stay safe. When you feel stable, bring the top leg in and place your foot on your inner thigh. After you have held it for about 30 seconds, lift your hips a little for the remainder of the minute, and don’t forget to do both sides!
It’s easy to get bored of doing abdominal work, often repeating the same few exercises and not being creative, but when you change it up, your muscles will be surprised and give you quicker results. Continuously adding variety into your routine will not only keep your muscles guessing, it will also make it more enjoyable for you.
By Leslie Awdykowyz
OTL Magazine