With my busy schedule I often find it difficult to dedicate some time to working out. However, with a little effort, I manage to squeeze in 10 minutes a day for some much-needed strength training. Doing so has enabled me to see a big difference in my core muscles. I was also pretty amazed to discover how quickly my body responded to the exercises. These days, no matter where I am, I find a way to get a workout done, and though I don't have the set of abs I did in my twenties, I have never looked or felt better.

Check out the following four core exercises by trainer Larysa DiDio, who created this Fit in 10 routine. To add more moves to your work out, check out her Fit in 10 DVD.

Perform each exercise for 45 seconds, resting for 30 seconds between each one. Repeat each workout twice.

1. Upper Ab Crunch

Here's how: Keep your knees bent and your feet flat on the floor. To make this exercise easier to do, place a mini exercise ball or a rolled up towel underneath your shoulder blades. Bring your hands behind your head and keep your elbows out to the sides. As you lift your upper torso, crunch your abs and lift, lifting your chin and chest a few inches higher. Return to the starting position and continue the movement for 45 seconds.

Image by Mitch Mandel