For our ancestors, "work" was related to basic survival -- hunting for food, toiling away under a blazing sun or lugging water from a source miles away. Sitting, when it happened, was used as a way to recuperate from the tough physical labor required to survive. These days, it's hard to find a job that doesn't involve sitting in a chair and click-clacking away at a keyboard for eight hours a day. But instead of the cushy office chairs leaving us well-rested, our sedentary lifestyle is taking its toll. The truth of the matter is, it isn't just your imagination -- your desk job is slowly killing you.

Even if you work out regularly, a single burst of activity doesn't combat the damage done by sitting for eight to nine hours a day. One study found that each hour spent sitting, regardless of time spent exercising, increases your chance of heart disease by 14 percent. The solution: small, frequent breaks that activate your muscles and your metabolism. And while "deskercise" sounds great in theory, unless you work at Lululemon, you're going to get some raised eyebrows if you try doing lunges from your desk to the break room.

That's why we've come up with a full day of exercises and tips to combat the sitting disease. Here, the best workouts you can do at work -- without getting called into HR for curling with your cubicle partner's stapler or stealing paper reams for leg presses.

It's a battle you face daily: to take the stairs, or not to take the stairs? But saying "yes" to the steps -- a two-minute commitment -- could help you live longer. In one long-term study of 10,000 men, those who climbed about three to five flights of stairs per day had a 29 percent reduction of their risk of stroke.

Three flights of stairs four times a day (entering, lunch and exiting) will burn an extra 60 calories per day. And since U.S. adults gain, on average, about a pound per year, an extra two minutes of stair-walking can help eliminate that.

Plus, every time your heart rate goes up, your body releases chemical endorphins that make you feel happy and calm. That's a better way to start the workday than, say, making awkward small talk with someone in the elevator before you've had your coffee.

Experts suggest moving every hour to counteract the effects of a sedentary lifestyle. Get up and move around for at least five minutes -- get some water (it's a natural appetite suppressant, if you're trying to avoid the office treat jar), refill your coffee mug (a recent study shows that drinking four cups a day reduces your risk of melanoma by 20 percent) or just take a step outside.

Bonus points if you leave your phone at your desk during your five-minute break. Giving your eyes a break is just as important as getting up every hour. Eyestrain from looking at a computer all day can cause dry eyes, blurred vision and headaches.

While most of your muscles are at rest during the average workday, there is a body part that is getting one heck of a workout: the wrist. Carpal tunnel syndrome (CTS) is on the rise, and anyone who's spent a day in front of a keyboard knows that tingling, aching feeling can last a lot longer than working hours. To ward off CTS, the Chartered Society of Physiotherapy recommends these exercises:

Wrist bend:
Rest your elbow on a table, arm pointing up, wrist straight. Gently bend your wrist forward at a right angle and hold for five seconds. Straighten your wrist. Gently bend it backwards and hold for five seconds. Do three sets of 10 repetitions.

Wrist flex:
Keeping your arm straight in front with your palm facing down, gently bend your wrist down. Use the opposite hand to press the stretching hand back towards your body and hold for 15 to 30 seconds. Straighten your wrist. Gently bend the stretching hand backwards and use the opposite hand to pull the fingers back. Hold for 15 to 30 seconds. Do three sets with each wrist

Hand squeeze:
Squeeze a rubber ball (or ball your hands into a fist) and hold for five seconds. Do three sets of 10 repetitions.

Time to walk away from your desk for the full lunch hour. Resisting the urge to shovel food into your mouth while you work through your lunch hour can have a big payoff -- for your health and for your job. Studies suggest that taking a break can actually improve your concentration and engagement, improving both individual and company performance.