Most stationary bikes have a display to tell you how far you've pedaled.
Take a look at stationary bicycles in a gym or a fitness store and you're likely to see models with a variety of bells and whistles. One fairly typical item on the control panel of stationary bikes is a display that converts pedaling into distance. The bike doesn't move, of course, but the distance reading offers a frame of reference to help you measure your effort and your workout's intensity - assuming, of course, that the numbers are accurate.
Measure Your Distance
As with most machines, the accuracy of an exercise bike's odometer, or distance display, depends on how well the bicycle is built. Each stationary bicycle manufacturer programs its bike displays based on the company's formula. In theory, determining the distance on a bike is a straightforward calculation. Just multiply the tire's circumference by the number of revolutions. As long as the bike's electronics are working properly, most machines are accurate when performing a simple distance measurement, and this includes stationary bicycles.
Compare Distance and Speed
If you increase your pedaling speed on a stationary bike, you will also increase the distance if your workout time remains the same. Even if the bike's distance display isn't 100-percent accurate, it can remain a usable resource because you'll still see your distance increase from workout to workout, if you increase your speed. For example, if you pedal at 10 mph for 30 minutes, you'll travel 5 miles. Increase your speed to 15 mph and you'll pedal 7.5 miles in a half hour. There is also a benefit to working more intensely for a shorter distance. Performing an interval workout in which you alternate high- and low-intensity pedaling can burn more calories than pedaling at the same pace over a longer distance.
Take a Ride
Riding a stationary bike is an efficient, non-impact cardio exercise that's very friendly on your joints. Make sure the bike is on a level surface, with the bike's seat parallel with the floor. Adjust the seat if necessary so your knee is very slightly bent when your foot is at the bottom of the pedaling cycle. Riding the bike regularly - about 30 minutes per day, five days per week - can help you burn calories and reduce your risk for conditions such as high blood pressure and type 2 diabetes. If you weigh 185 pounds, a moderate, 30-minute session on a stationary bike burns about 311 calories, while a vigorous workout will burn about 466 calories.
Other Tracking Ideas
If you don't want to use a stationary bike's distance display, you have other options for tracking your workout. You can time your session using the bike's display, a stopwatch or a clock on the wall. You can also judge your workout according to your exertion level. If you're sweating lightly and can talk fairly normally but can't sing, then you're doing moderate exercise. If you're sweating heavily and must stop speaking to breathe after just a few words, you're exercising vigorously. Finally, you can also monitor your heart rate. Subtract your age from 220 if you're a man and 226 if you're a woman to estimate your maximum heart rate. Keep your pulse rate between 50 to 70 percent of your maximum to exercise moderately and between 70 to 85 percent for a vigorous workout.