Want to see your progress as you get fit? You could write it down, or try a device that will give you data on every step you take, the calories you burn, your heart rate, and even your movements as you sleep.
You don't need to -- what matters is that you get out there and exercise. But seeing the numbers can be motivating.
If you need motivation to get moving, pedometers that count each step can help.
"People are often surprised when they strap on a step counter to see how inactive they are during the day," says Ruth Ann Carpenter, a wellness consultant and co-author of Active Living Every Day.
"With a step counter, you can set a goal of how many steps to take every day and track your progress," she says. "If you're falling short, you may be motivated to take a walk after dinner instead of watching TV."
Step counters are valuable for people who get their exercise by walking or running. It won't accurately register other exercise, such as bicycling or weightlifting. About 5,000 steps is the minimum you should log in a day, and 10,000 steps is ideal.
The most basic and inexpensive pedometers measure steps only when worn or held upright. More expensive models use triaxial or 3D technology to record steps no matter how they are positioned, so they tend to be easier to use and more reliable.
2. GPS-Based Fitness Monitors
GPS signals monitor your exact location. GPS-equipped devices can record how far and how fast you walk or run. You can also use them to chart a path when you're running or walking in an unfamiliar place.
GPS devices are generally more accurate than basic step counters at estimating the distance you've walked or run.
3. Calorie Counters
Some pedometers and GPS devices use your steps and speed to estimate the number of calories you burned. The most sophisticated of these programs let you enter information about your weight, which improves accuracy.
Some devices are better than others at making the calculation. "You usually get what you pay for," says Catherine G.R. Jackson, PhD, kinesiology professor at California State University, Fresno. "The more expensive units are typically more accurate."
Even the best give only an estimate.
4. Heart Rate Monitors
Your heart rate is the number of times your heart beats each minute, which goes up when you exercise. So heart rate monitors measure the intensity of your workout. Along with displaying heart rate in real time, many devices let you set a target heart rate and then alert you when you reach your target.
Heart rate monitors can help beginning exercisers tell if their workout is moderate or challenging. High-level athletes can use heart rate monitors to make sure they reach and remain in their target heart rate zone.