If you don't track it, did you really even do it? (haha)
That is a joke, but it is a common thought when people share about their workouts or workout achievements. I think people just like to see proof of said workout and could be for any number of reasons. For my "proof" I use Endomondo. I use it for hiking, walking and riding mainly, but have been thinking of getting a step tracker and track what I do at work. I did a test run with a step counter and I do about 9-12k steps just at work.
If you have not used Endomondo or have not heard of it, it is a free application that offers a wide array of services. Some of the more detailed information is in the premium service such as weather and heart rate, but I have gotten by on the free service for years and it gives me a good idea of how much I’m getting outside and for how long. You can get maps, routes, set goals for yourself and allow others to join in a challenge. It is overall good functional app that doesn’t take a lot of battery life and can help keep you on track of your workouts for personal goals or just challenge yourself to exercise more.