Have you ever stayed in a tall hotel while on vacation? Upon checking in, you might have learned that your room number was 423. Wow! You're all the way up on the fourth floor. With your bags in your hands, you head out of the lobby and you're faced with a decision: elevator or stairs?

If you're tired and your bags are heavy, you probably head straight for the elevator. If you want a short workout instead, you probably head for the stairs. Since we've all climbed stairs before, you probably know that walking up even a short flight of stairs is a good way to get your heart pumping faster.

When you think of vigorous cardiovascular exercise — the kind that really gets your heart beating — you might think of power walking, jogging, or running. Fitness experts will tell you that you should also add stair climbing to that list.

When you climb up stairs, you're forced to move your body weight upward, against the force of gravity. This requires more effort than simply walking on a flat surface. In fact, stair climbing burns roughly two to three times more energy than walking.

How many calories can you burn when climbing stairs? Experts estimate that climbing up a flight of 20 stairs burns about three calories. While that might not sound like a lot, it's more calories per minute than jogging. You also burn about one calorie for every 20 stairs you walk down.

In addition to the health benefits of cardiovascular exercise that stair climbing provides, taking the stairs can also save you time. If you work in an office building, you can waste a lot of time waiting for elevators. Researchers estimate that office workers could save up to 15 minutes per day just by taking the stairs.

If you want to improve your health by climbing stairs, you may be WONDERing where in the world the longest stairway is. According to the Guinness Book of World Records, the world's longest stairway is the service stairway for the railway that travels up Mt. Niesen near Spiez, Switzerland.

The stairway has 11,674 steps that span over two miles! Although the stairway is usually closed for safety reasons, once each year it is opened for the "Niesenlauf," an annual race in which up to 500 participants climb the stairs as quickly as they can. Think you could climb that many stairs? Getting to the top would be equivalent to climbing to the top of the Empire State Building more than seven times!

Wonder What's Next?

Tomorrow’s Wonder of the Day features a juicy fruit that could really use a shave!