It's one thing to want to get fit, but it's a whole other thing to actually do it. Going from couch potato to enthusiastic exerciser takes some serious motivation and a fitness plan that's easy to follow.

We went to celebrity fitness guru David Kirsch—the man behind the bodies of Heidi Klum and Anne Hathaway—to get his tips for getting your butt off the couch and working out. His simple plan will help you get toned, without having to morph into a total gym rat.

Set Reasonable Goals

The easiest way to discourage yourself is to set an unreasonable goal—there will be no way for you to hit it and you'll wind up getting frustrated and giving up. Kirsch recommends setting an obtainable goal, such as "I want to lose five pounds," or "I want to fit into my skinny jeans."

It's also important to be realistic about your time frame and the amount of exercise you do each day. Don't start off at two hours a day—you'll burn out. If you are not sure what you're doing, find a good trainer or training material to guide you.

Movement = Exercise

"You don't need to go to the gym to exercise," says Kirsch. The easiest way to start your new fitness routine is to incorporate exercise into your daily routine. When you get out of bed in the morning, before heading to the shower, do 15 knee bends, 15 lunges and 15 crunches. When you're making breakfast, do some isometric contractions: squeeze and release your abs, your butt, your thighs.

Get your body moving with a 10 minute express workout—be it yoga or stretching or cardio—every day before work. If you start that way and build from that, you're more likely to stick with a program.

Find Time For Fitness

Feel like there's no time in the day to squeeze in exercise? Kirsch says that any exercise is beneficial, no matter how little. The reality is that our lifestyles are conflicting and everyone has different physical needs for exercise. Ideally, you should be doing an hour of exercise a day, but if you can only find time for 10 minutes, than 10 minutes of focused training beats doing nothing.

Stay Focused

According to Kirsch, the number one biggest mistake women make while exercising is not focusing on what they are doing. That means no more cell phone, no more magazines and no more TV while you are working out. You need to make the most of your time at the gym while you are there. Sitting on the treadmill and talking on the phone doesn't give you the exercise you really need. Whatever you are doing, focus. Connect your brain and your body so you can really focus on what you are trying to accomplish.