Need an edge to land that big promotion at work? Are you nervous about an upcoming presentation? There is a secret that most successful CEOs share. They work out — almost every day.

Staying in shape and eating right makes you work more efficiently and productively. What’s more, working out on a regular basis leads you to make better eating choices. For example, you’re more likely to have a healthy salad then eat yourself into a carb coma at lunch when you have a regular fitness routine.

You’re stress level will also be reduced if you hop on the Stairmaster. Fitness improves oxygen delivery to organs, heightens circulation, and cuts back on doctor visits and sick days.

Regular exercise and proper diet can improve your performance at work in many ways. Here’s how:

• 7 a.m.: Do you find yourself constantly running late? Do you rush to catch the subway or rush to get into work on time? If you exercise regularly you won’t be sweaty, stressed, and or too winded to say hello to the people you do business with.

• 9 a.m.: Early morning presentation? If you're used to that 6 a.m. spin class, this speech will be a breeze to get through, with less hills to climb.

• Noon: People who walk around town or the park during lunch feel less ragged and overworked. Some of the best work ideas have come to me while running around the reservoir track in Central Park.

• 3 p.m.: Big meeting at the end of the day but feeling the 3 p.m. slump? If you’re not fit, coffee may be the only thing that gets you through the day, still half in a fog. But instead of dehydrating on caffeine, a lunch-time walk has you more focused and gives you time to think quietly and plan your talking points. If you’re a stay-at-home mom or day, you won’t feel sluggish and wish for a 3 p.m. nap lust if you’re used to pumping iron at 5 p.m.

• 6 p.m.: At the end of the day your back muscles may be tight and you may have a headache.  If you can't work out in the morning try taking a class at the gym or exercising after work. It may help those muscles loosen up.

• 11 p.m.: Are the stressors of the day keeping you up at night? If you jogged during the day, you’ll be sleepy with a clear mind, and better rested when you awake to tackle your tasks. More exercise = better sleep = better work day.